<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Apache Dubbo – Configuration Framework and Service Behavior</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/</link><description>Recent content in Configuration Framework and Service Behavior on Apache Dubbo</description><generator>Hugo -- gohugo.io</generator><language>en</language><atom:link href="https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/index.xml" rel="self" type="application/rss+xml"/><item><title>Docs3-V2: Check at startup</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/preflight-check/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/preflight-check/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>By default, Dubbo will check whether the dependent service is available at startup, and will throw an exception when it is unavailable, preventing Spring initialization from completing, so that problems can be detected early when going online. The default &lt;code>check=&amp;quot;true&amp;quot;&lt;/code>.&lt;/p>
&lt;p>Checking can be turned off by &lt;code>check=&amp;quot;false&amp;quot;&lt;/code>. For example, when testing, some services do not care, or there is a circular dependency, and one of them must be started first.&lt;/p>
&lt;p>In addition, if your Spring container is lazy-loaded, or if you delay the reference service through API programming, please turn off check, otherwise when the service is temporarily unavailable, an exception will be thrown and a null reference will be obtained. If &lt;code>check=&amp;quot;false&amp;quot;&lt;/code>, always Yes, it will return the reference, and when the service is restored, it can be connected automatically.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;ul>
&lt;li>One-way dependency: with dependency (recommended default setting) and without dependency (check=false can be set)&lt;/li>
&lt;li>Interdependence: that is, circular dependency, (it is not recommended to set check=false)&lt;/li>
&lt;li>Lazy loading handling&lt;/li>
&lt;/ul>
&lt;blockquote>
&lt;p>check is only used to check at startup, if there is no corresponding dependency at runtime, an error will still be reported.&lt;/p>
&lt;/blockquote>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="via-spring-configuration-file">via spring configuration file&lt;/h3>
&lt;p>Turn off startup checks for a service&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> check=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Turn off startup checks for all services&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:consumer&lt;/span> check=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Turn off registry checks at startup&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> check=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="via-dubboproperties">via dubbo.properties&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-properties" data-lang="properties">&lt;span style="display:flex;">&lt;span>dubbo.reference.com.foo.BarService.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">false&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>dubbo.consumer.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">false&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>dubbo.registry.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">false&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="via-the--d-parameter">via the -D parameter&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-sh" data-lang="sh">&lt;span style="display:flex;">&lt;span>java -Ddubbo.reference.com.foo.BarService.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#b58900">false&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>java -Ddubbo.consumer.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#b58900">false&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>java -Ddubbo.registry.check&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#b58900">false&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="meaning-of-configuration">Meaning of configuration&lt;/h2>
&lt;p>&lt;code>dubbo.reference.com.foo.BarService.check&lt;/code>, overrides the check value of the reference of &lt;code>com.foo.BarService&lt;/code>, even if there is a statement in the configuration, it will be overwritten.&lt;/p>
&lt;p>&lt;code>dubbo.consumer.check=false&lt;/code> is the default value of &lt;code>check&lt;/code> for setting reference. If there is an explicit statement in the configuration, such as: &lt;code>&amp;lt;dubbo:reference check=&amp;quot;true&amp;quot;/&amp;gt;&lt;/code>, it will not be affected influences.&lt;/p>
&lt;p>&lt;code>dubbo.registry.check=false&lt;/code>, the first two means that the subscription is successful, but whether the provider list is empty or whether an error is reported, if the registration subscription fails, it is also allowed to start, you need to use this option, and will retry periodically in the background .&lt;/p></description></item><item><title>Docs3-V2: Distributed Transactions</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/transaction/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/transaction/</guid><description>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="first-step">&lt;strong>First step&lt;/strong>&lt;/h3>
&lt;p>First visit: &lt;a href="https://seata.io/zh-cn/blog/download.html">https://seata.io/zh-cn/blog/download.html&lt;/a>&lt;/p>
&lt;p>Download the seata1.5.2 service we need to use&lt;/p>
&lt;h3 id="second-step">&lt;strong>Second step&lt;/strong>&lt;/h3>
&lt;ol>
&lt;li>Add the undo_log table to your database participating in global transactions (TCC, SAGA, XA can skip this step)&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-sql" data-lang="sql">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">-- for AT mode you must to init this sql for you business database. the seata server not need it.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">CREATE&lt;/span> &lt;span style="color:#719e07">TABLE&lt;/span> &lt;span style="color:#719e07">IF&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">EXISTS&lt;/span> &lt;span style="color:#719e07">`&lt;/span>undo_log&lt;span style="color:#719e07">`&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>(
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span>(&lt;span style="color:#2aa198">20&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;branch transaction id&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">100&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;global transaction id&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>context&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">128&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;undo_log context, such as serialization&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>rollback_info&lt;span style="color:#719e07">`&lt;/span> LONGBLOB &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;rollback info&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>log_status&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">INT&lt;/span>(&lt;span style="color:#2aa198">11&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;0: normal status,1: defense status&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>log_created&lt;span style="color:#719e07">`&lt;/span> DATETIME(&lt;span style="color:#2aa198">6&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;create datetime&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>log_modified&lt;span style="color:#719e07">`&lt;/span> DATETIME(&lt;span style="color:#2aa198">6&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span> &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#2aa198">&amp;#39;modify datetime&amp;#39;&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">UNIQUE&lt;/span> &lt;span style="color:#719e07">KEY&lt;/span> &lt;span style="color:#719e07">`&lt;/span>ux_undo_log&lt;span style="color:#719e07">`&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span>, &lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span>)
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>) ENGINE &lt;span style="color:#719e07">=&lt;/span> InnoDB
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> AUTO_INCREMENT &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">1&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">DEFAULT&lt;/span> CHARSET &lt;span style="color:#719e07">=&lt;/span> utf8 &lt;span style="color:#719e07">COMMENT&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#39;AT transaction mode undo table&amp;#39;&lt;/span>;
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="2">
&lt;li>Create a library named seata in your mysql database, and use the following sql&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-sql" data-lang="sql">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">-- -------------------------------- The script used when storeMode is &amp;#39;db&amp;#39; ------- -------------------------
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">-- the table to store GlobalSession data
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">CREATE&lt;/span> &lt;span style="color:#719e07">TABLE&lt;/span> &lt;span style="color:#719e07">IF&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">EXISTS&lt;/span> &lt;span style="color:#719e07">`&lt;/span>global_table&lt;span style="color:#719e07">`&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>(
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">128&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>transaction_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>status&lt;span style="color:#719e07">`&lt;/span> TINYINT &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>application_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">32&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>transaction_service_group&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">32&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>transaction_name&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">128&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>timeout&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">INT&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>begin_time&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>application_data&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">2000&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_create&lt;span style="color:#719e07">`&lt;/span> DATETIME,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_modified&lt;span style="color:#719e07">`&lt;/span> DATETIME,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">PRIMARY&lt;/span> &lt;span style="color:#719e07">KEY&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">KEY&lt;/span> &lt;span style="color:#719e07">`&lt;/span>idx_gmt_modified_status&lt;span style="color:#719e07">`&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>gmt_modified&lt;span style="color:#719e07">`&lt;/span>, &lt;span style="color:#719e07">`&lt;/span>status&lt;span style="color:#719e07">`&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">KEY&lt;/span> &lt;span style="color:#719e07">`&lt;/span>idx_transaction_id&lt;span style="color:#719e07">`&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>transaction_id&lt;span style="color:#719e07">`&lt;/span>)
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>) ENGINE &lt;span style="color:#719e07">=&lt;/span> InnoDB
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">DEFAULT&lt;/span> CHARSET &lt;span style="color:#719e07">=&lt;/span> utf8;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">-- the table to store BranchSession data
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">CREATE&lt;/span> &lt;span style="color:#719e07">TABLE&lt;/span> &lt;span style="color:#719e07">IF&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">EXISTS&lt;/span> &lt;span style="color:#719e07">`&lt;/span>branch_table&lt;span style="color:#719e07">`&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>(
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">128&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>transaction_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>resource_group_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">32&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>resource_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">256&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>branch_type&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">8&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>status&lt;span style="color:#719e07">`&lt;/span> TINYINT,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>client_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">64&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>application_data&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">2000&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_create&lt;span style="color:#719e07">`&lt;/span> DATETIME(&lt;span style="color:#2aa198">6&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_modified&lt;span style="color:#719e07">`&lt;/span> DATETIME(&lt;span style="color:#2aa198">6&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">PRIMARY&lt;/span> &lt;span style="color:#719e07">KEY&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">KEY&lt;/span> &lt;span style="color:#719e07">`&lt;/span>idx_xid&lt;span style="color:#719e07">`&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span>)
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>) ENGINE &lt;span style="color:#719e07">=&lt;/span> InnoDB
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">DEFAULT&lt;/span> CHARSET &lt;span style="color:#719e07">=&lt;/span> utf8;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">-- the table to store lock data
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">CREATE&lt;/span> &lt;span style="color:#719e07">TABLE&lt;/span> &lt;span style="color:#719e07">IF&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">EXISTS&lt;/span> &lt;span style="color:#719e07">`&lt;/span>lock_table&lt;span style="color:#719e07">`&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>(
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>row_key&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">128&lt;/span>) &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>xid&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">96&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>transaction_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">BIGINT&lt;/span> &lt;span style="color:#719e07">NOT&lt;/span> &lt;span style="color:#719e07">NULL&lt;/span>,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>resource_id&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">256&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>&lt;span style="color:#719e07">table_name&lt;/span>&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">32&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>pk&lt;span style="color:#719e07">`&lt;/span> &lt;span style="color:#b58900">VARCHAR&lt;/span>(&lt;span style="color:#2aa198">36&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_create&lt;span style="color:#719e07">`&lt;/span> DATETIME,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">`&lt;/span>gmt_modified&lt;span style="color:#719e07">`&lt;/span> DATETIME,
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">PRIMARY&lt;/span> &lt;span style="color:#719e07">KEY&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>row_key&lt;span style="color:#719e07">`&lt;/span>),
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">KEY&lt;/span> &lt;span style="color:#719e07">`&lt;/span>idx_branch_id&lt;span style="color:#719e07">`&lt;/span> (&lt;span style="color:#719e07">`&lt;/span>branch_id&lt;span style="color:#719e07">`&lt;/span>)
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>) ENGINE &lt;span style="color:#719e07">=&lt;/span> InnoDB
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">DEFAULT&lt;/span> CHARSET &lt;span style="color:#719e07">=&lt;/span> utf8;
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="third-step">&lt;strong>third step&lt;/strong>&lt;/h3>
&lt;p>Introduce seata dependency into your project&lt;/p>
&lt;p>spring-boot application:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-fallback" data-lang="fallback">&lt;span style="display:flex;">&lt;span> &amp;lt;dependency&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;groupId&amp;gt;io.seata&amp;lt;/groupId&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;artifactId&amp;gt;seata-spring-boot-starter&amp;lt;/artifactId&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;version&amp;gt;1.5.2&amp;lt;/version&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;/dependency&amp;gt;
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>spring application:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-fallback" data-lang="fallback">&lt;span style="display:flex;">&lt;span> &amp;lt;dependency&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;groupId&amp;gt;io.seata&amp;lt;/groupId&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;artifactId&amp;gt;seata-all&amp;lt;/artifactId&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;version&amp;gt;1.5.2&amp;lt;/version&amp;gt;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &amp;lt;/dependency&amp;gt;
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="the-fourth-step">&lt;strong>the fourth step&lt;/strong>&lt;/h3>
&lt;p>spring-boot application:&lt;/p>
&lt;p>Reference &lt;a href="https://github.com/seata/seata/tree/develop/script/client/spring">seata/script/client/spring at develop seata/seata (github.com)&lt;/a>&lt;/p>
&lt;p>Add it to your project&amp;rsquo;s application.yml.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-yaml" data-lang="yaml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">seata&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">enabled&lt;/span>: &lt;span style="color:#cb4b16">true&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">application-id&lt;/span>: applicationName
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">tx-service-group&lt;/span>: my_test_tx_group
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">enable-auto-data-source-proxy&lt;/span>: &lt;span style="color:#cb4b16">true&lt;/span> &lt;span style="color:#586e75">#Only AT and XA modes need to be true, and the data source will be automatically proxied after opening&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">data-source-proxy-mode&lt;/span>: AT &lt;span style="color:#586e75">#Optional AT&amp;amp;XA&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">config&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">type&lt;/span>: nacos
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">nacos&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#namespace: If the configuration is created in a non-default namespace, please fill in the id of the namespace here&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">serverAddr&lt;/span>: &lt;span style="color:#2aa198">127.0.0.1&lt;/span>:&lt;span style="color:#2aa198">8848&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">group&lt;/span>: SEATA_GROUP
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">username&lt;/span>: &lt;span style="color:#2aa198">&amp;#34;nacos&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">password&lt;/span>: &lt;span style="color:#2aa198">&amp;#34;nacos&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">data-id&lt;/span>: seata.properties
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">registry&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">type&lt;/span>: nacos
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">nacos&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">application&lt;/span>: seata-server
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">server-addr&lt;/span>: &lt;span style="color:#2aa198">127.0.0.1&lt;/span>:&lt;span style="color:#2aa198">8848&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">group&lt;/span>: SEATA_GROUP
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#namespace: If the configuration is created in a non-default namespace, please fill in the id of the namespace here&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">username&lt;/span>: &lt;span style="color:#2aa198">&amp;#34;nacos&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">password&lt;/span>: &lt;span style="color:#2aa198">&amp;#34;nacos&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>spring application:&lt;/p>
&lt;p>Add &lt;a href="https://github.com/seata/seata/tree/develop/script/client/conf">seata/script/client/conf at develop · seata/seata (github.com)&lt;/a> under registry.conf, because High-availability deployment uses a third-party configuration center, so file.conf is not required&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-fallback" data-lang="fallback">&lt;span style="display:flex;">&lt;span>registry {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> # file, nacos, eureka, redis, zk, consul, etcd3, sofa, custom
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> type = &amp;#34;nacos&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> nacos {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> application = &amp;#34;seata-server&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serverAddr = &amp;#34;127.0.0.1:8848&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> group = &amp;#34;SEATA_GROUP&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> namespace = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> username = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> password = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ##if use MSE Nacos with auth, mutex with username/password attribute
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> #accessKey = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> #secretKey = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ##if use Nacos naming meta-data for SLB service registry, specify nacos address pattern rules here
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> #slbPattern = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> }
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>config {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> # file, nacos, apollo, zk, consul, etcd3, springCloudConfig, custom
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> type = &amp;#34;nacos&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> nacos {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serverAddr = &amp;#34;127.0.0.1:8848&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> namespace = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> group = &amp;#34;SEATA_GROUP&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> username = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> password = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ##if use MSE Nacos with auth, mutex with username/password attribute
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> #accessKey = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> #secretKey = &amp;#34;&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> dataId = &amp;#34;seata.properties&amp;#34;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> }
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="the-fifth-step">&lt;strong>the fifth step&lt;/strong>&lt;/h3>
&lt;p>Run the nacos you downloaded, and refer to [https://github.com/seata/seata/tree/develop/script/config-center](&lt;a href="https://gitee.com/link?target=https%3A%2F%25">https://gitee.com/link?target=https%3A%2F%&lt;/a> 2Fgithub.com%2Fseata%2Fseata%2Ftree%2Fdevelop%2Fscript%2Fconfig-center) and modify the config.txt&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-properties" data-lang="properties">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">#Only used by client&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">#The transaction group is called my_test_tx_group and the corresponding seata-server cluster is default&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service.vgroupMapping.my_test_tx_group&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">default&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">#The following are only used by server&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.mode&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">db&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.datasource&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">druid&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.dbType&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">mysql&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.driverClassName&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">com.mysql.jdbc.Driver&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.url&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.user&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">username&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.password&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">password&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.minConn&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">5&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.maxConn&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">30&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.globalTable&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">global_table&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.branchTable&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">branch_table&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.queryLimit&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">100&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.lockTable&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">lock_table&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>store.db.maxWait&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">5000&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Open the nacos console, create a configuration whose dataId is seata.properties under the corresponding namespace, fill in the group as SEATA_GROUP, and fill in the above content and select the type as properties to save
&lt;img src="https://dubbo.apache.org/imgs/blog/Dingtalk_20220724021635.jpg" alt="Dingtalk_20220724021635.jpg.png" style="zoom:50%;" />&lt;/p>
&lt;h3 id="step-6">&lt;strong>Step 6&lt;/strong>&lt;/h3>
&lt;p>Change application.yml in server&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-yaml" data-lang="yaml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">server&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">port&lt;/span>: &lt;span style="color:#2aa198">7091&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">spring&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">application&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">name&lt;/span>: seata-server
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">record&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">config&lt;/span>: classpath:logback-spring.xml
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">file&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">path&lt;/span>: ${user.home}/logs/seata
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">console&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">user&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">username&lt;/span>: seata
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">password&lt;/span>: seata
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">seata&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">config&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75"># support: nacos, consul, apollo, zk, etcd3&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">type&lt;/span>: nacos
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">nacos&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">server-addr&lt;/span>: &lt;span style="color:#2aa198">127.0.0.1&lt;/span>:&lt;span style="color:#2aa198">8848&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#namespace: If the configuration is created in a non-default namespace, please fill in the id of the namespace here&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">group&lt;/span>: SEATA_GROUP
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">username&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">password&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">##if use MSE Nacos with auth, mutex with username/password attribute&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#access-key: &amp;#34;&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#secret-key: &amp;#34;&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">data-id&lt;/span>: seata.properties
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">registry&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75"># support: nacos, eureka, redis, zk, consul, etcd3, sofa&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">type&lt;/span>: nacos
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">nacos&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">application&lt;/span>: seata-server
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">server-addr&lt;/span>: &lt;span style="color:#2aa198">127.0.0.1&lt;/span>:&lt;span style="color:#2aa198">8848&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">group&lt;/span>: SEATA_GROUP
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">namespace&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">cluster&lt;/span>: default
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#namespace: If the configuration is created in a non-default namespace, please fill in the id of the namespace here&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">password&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">##if use MSE Nacos with auth, mutex with username/password attribute&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#access-key: &amp;#34;&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">#secret-key: &amp;#34;&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"># server:&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"># service-port: 8091 #If not configured, the default is &amp;#39;${server.port} + 1000&amp;#39;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">security&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">secretKey&lt;/span>: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">tokenValidityInMilliseconds&lt;/span>: &lt;span style="color:#2aa198">1800000&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">ignore&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">urls&lt;/span>: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*. png, /**/*.ico, /console-fe/public/**, /api/v1/auth/login
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="step-seven">&lt;strong>Step Seven&lt;/strong>&lt;/h3>
&lt;p>An example of adding @GlobalTransactional to the interface of the global transaction caller (the service that initiates the global transaction) is as follows:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@GetMapping&lt;/span>&lt;span style="color:#719e07">(&lt;/span>value &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;testCommit&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@GlobalTransactional&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> Object &lt;span style="color:#268bd2">testCommit&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#268bd2">@RequestParam&lt;/span>&lt;span style="color:#719e07">(&lt;/span>name &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;id&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>defaultValue &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span> Integer id&lt;span style="color:#719e07">,&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@RequestParam&lt;/span>&lt;span style="color:#719e07">(&lt;/span>name &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;sum&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> defaultValue &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span> Integer sum&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Boolean ok &lt;span style="color:#719e07">=&lt;/span> productService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">reduceStock&lt;/span>&lt;span style="color:#719e07">(&lt;/span>id&lt;span style="color:#719e07">,&lt;/span> sum&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">if&lt;/span> &lt;span style="color:#719e07">(&lt;/span>ok&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> LocalDateTime now &lt;span style="color:#719e07">=&lt;/span> LocalDateTime&lt;span style="color:#719e07">.&lt;/span>now&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Orders orders &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Orders&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> orders&lt;span style="color:#719e07">.&lt;/span>setCreateTime&lt;span style="color:#719e07">(&lt;/span>now&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> orders&lt;span style="color:#719e07">.&lt;/span>setProductId&lt;span style="color:#719e07">(&lt;/span>id&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> orders&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">setReplaceTime&lt;/span>&lt;span style="color:#719e07">(&lt;/span>now&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> orders&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">setSum&lt;/span>&lt;span style="color:#719e07">(&lt;/span>sum&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> orderService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">save&lt;/span>&lt;span style="color:#719e07">(&lt;/span>orders&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;ok&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">else&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;fail&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Spring applications need to manually proxy the data source to select the transaction mode and initialize the transaction scanner when using AT or XA mode&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@Primary&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@Bean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;dataSource&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> DataSource &lt;span style="color:#268bd2">dataSource&lt;/span>&lt;span style="color:#719e07">(&lt;/span>DataSource druidDataSource&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//AT agent choose one of the two
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> DataSourceProxy&lt;span style="color:#719e07">(&lt;/span>druidDataSource&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//XA Proxy
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> DataSourceProxyXA&lt;span style="color:#719e07">(&lt;/span>druidDataSource&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Bean&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> GlobalTransactionScanner &lt;span style="color:#268bd2">globalTransactionScanner&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> GlobalTransactionScanner&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;application name&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;my_test_tx_group&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>If you use tcc mode, you need to additionally define two-stage try and confirm(commit) cancel(rollback) in the serviceimpl of the corresponding provider&lt;/p>
&lt;p>The spring-boot application needs to close the data source proxy&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-yaml" data-lang="yaml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">seata&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">enable-auto-data-source-proxy&lt;/span>: &lt;span style="color:#cb4b16">false&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">/**
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * Define two-phase commit name = the bean name of the tcc, globally unique commitMethod = commit is the two-phase confirmation method rollbackMethod = rollback is the two-phase cancellation method
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * useTCCFence=true is to enable anti-hanging
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * BusinessActionContextParameter annotation to pass parameters to the second stage
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> *
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @param params - input parameters
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @return String
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> */&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@TwoPhaseBusinessAction&lt;/span>&lt;span style="color:#719e07">(&lt;/span>name &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;beanName&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> commitMethod &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;commit&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> rollbackMethod &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;rollback&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> useTCCFence &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">insert&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#268bd2">@BusinessActionContextParameter&lt;/span>&lt;span style="color:#719e07">(&lt;/span>paramName &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;params&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span> Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> String&lt;span style="color:#719e07">&amp;gt;&lt;/span> params&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> logger&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;You can reserve resources here, or use the characteristics of tcc to mix with AT. In the second stage, use the messages stored here in the first stage and send them out through the second stage, such as redis, mq and other operations&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">/**
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * The confirmation method can be named otherwise, but it must be consistent with the commitMethod. The context can pass the parameters of the try method
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> *
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @param context context
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @return boolean
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> */&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">commit&lt;/span>&lt;span style="color:#719e07">(&lt;/span>BusinessActionContext context&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> logger&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Reserved resources are actually processed, or send mq messages and redis storage&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">/**
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * Two-stage cancellation method
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> *
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @param context context
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @return boolean
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> */&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">rollback&lt;/span>&lt;span style="color:#719e07">(&lt;/span>BusinessActionContext context&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> logger&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Release reserved resources, or clear the message cache sent when the first phase is ready to be submitted by the second phase&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>linux/macos&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-shell" data-lang="shell">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#b58900">cd&lt;/span> bin
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>sh seata-server.sh
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>windows&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-shell" data-lang="shell">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#b58900">cd&lt;/span> bin
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>./seata-server.bat
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Run seata-server, after success, run your own service dubbo provider&amp;amp;consumer&lt;/p>
&lt;h3 id="the-eighth-step-is-to-build-a-highly-available-seata-server">&lt;strong>The eighth step is to build a highly available Seata-server&lt;/strong>&lt;/h3>
&lt;p>Since seata-server supports the separation mode of computing and storage, and supports exposing service addresses to multiple registration centers, it only needs to be configured according to the sixth step and then expanded horizontally&lt;/p>
&lt;p>For details, please visit: &lt;a href="https://seata.io/">https://seata.io/&lt;/a>&lt;/p></description></item><item><title>Docs3-V2: Group Aggregation</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/group-merger/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/group-merger/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Aggregate the results by grouping and return the aggregated results, such as menu service, use group to distinguish multiple implementations of the same interface, now the consumer needs to call once from each group and return the result, and return the result after merging, so You can implement aggregated menu items.&lt;/p>
&lt;p>For relevant codes, please refer to &lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-merge">Samples in the dubbo project&lt;/a>&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Service Grouping and Multiple Versions&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="search-all-groups">Search all groups&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="merge-specified-groups">Merge specified groups&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;aaa,bbb&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="specify-method-merge">Specify method merge&lt;/h3>
&lt;p>Combine the results of the specified method, and other unspecified methods will only call one Group&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;getMenuItems&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="a-method-is-not-merged">A method is not merged&lt;/h3>
&lt;p>One method does not combine results, others combine results&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;getMenuItems&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="specify-merge-strategy">Specify merge strategy&lt;/h3>
&lt;p>Specify the merge strategy, the default is to automatically match according to the return value type, if there are two combiners of the same type, you need to specify the name of the combiner [Merge result extension](../../../reference-manual/spi/ description/merger)&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;getMenuItems&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;mymerge&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="specify-merge-method">Specify merge method&lt;/h3>
&lt;p>Specify the merge method to merge the specified method that returns the result of the call. The parameter type of the merge method must be the return result type itself&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MenuService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;getMenuItems&amp;#34;&lt;/span> merger=&lt;span style="color:#2aa198">&amp;#34;.addAll&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="hint">hint:&lt;/h4>
&lt;p>Supported since &lt;code>2.1.0&lt;/code> version&lt;/p></description></item><item><title>Docs3-V2: Port Protocol Multiplexing</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/port-unification/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/port-unification/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>By configuring the protocol, dubbo3 can support port protocol multiplexing.
For example, after using the Triple protocol to enable port multiplexing, you can add
Dubbo protocol support, and Qos protocol support. These protocols are identified by a unified port multiplexing
It can be used for service protocol migration, which is processed by the server, and can save ports and related resources and reduce the complexity of operation and maintenance.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/pu-server/pu-server-flow.png" alt="pu-server-image1">&lt;/p>
&lt;ul>
&lt;li>
&lt;p>In the service creation phase, different Protocol objects are created for export by obtaining the protocol configuration exported by the service from the Config layer. in the process of exporting
In , if it is not the first time to create a server with port multiplexing, the Exchanger will save the data passed by the protocol layer to the server for subsequent processing of messages of this protocol type.&lt;/p>
&lt;/li>
&lt;li>
&lt;p>When the client&amp;rsquo;s message is delivered, it will first be passed to the ProtocolDetector through the server. If the identification is completed, the client will be marked as the corresponding protocol. And configure the corresponding processing logic through WireProtocol, and finally hand it over to ChannelOperator to complete the binding of the underlying IO framework and the processing logic of the corresponding Dubbo framework.&lt;/p>
&lt;/li>
&lt;li>
&lt;p>After the above protocol identification is completed, the Channel has determined how to process the remote client message, and it can be processed through the corresponding ServerPipeline (the processing thread of the message will also be determined according to the configuration information during the processing).&lt;/p>
&lt;/li>
&lt;/ul>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>[https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-port-unification](&lt;a href="https://github.com/apache/dubbo-samples/tree/master/3-extensions/">https://github.com/apache/dubbo-samples/tree/master/3-extensions/&lt;/a> protocol/dubbo-samples-port-unification)&lt;/p>
&lt;h2 id="configuration-method">configuration method&lt;/h2>
&lt;p>For the configuration method supported by Dubbo, please refer to &lt;a href="https://dubbo.apache.org/zh-cn/overview/mannual/java-sdk/reference-manual/config/">Configuration Instructions&lt;/a>&lt;/p>
&lt;h3 id="service-multi-protocol-export">Service multi-protocol export&lt;/h3>
&lt;p>The ext-protocol parameter supports configuring multiple different protocols, and the protocols are separated by &amp;ldquo;,&amp;rdquo;.&lt;/p>
&lt;h4 id="xml-configuration">xml configuration&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;-1&amp;#34;&lt;/span> ext-protocol=&lt;span style="color:#2aa198">&amp;#34;tri,&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;greetingService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.demo.provider.GreetingServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> delay=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;greeting&amp;#34;&lt;/span> timeout=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.demo.GreetingService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;greetingService&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/ &amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="api-configuration">API configuration&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ProtocolConfig config &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>CommonConstants&lt;span style="color:#719e07">.&lt;/span>TRIPLE&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">-&lt;/span>1&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>config&lt;span style="color:#719e07">.&lt;/span>setExtProtocol&lt;span style="color:#719e07">(&lt;/span>CommonConstants&lt;span style="color:#719e07">.&lt;/span>DUBBO&lt;span style="color:#719e07">+&lt;/span>&lt;span style="color:#2aa198">&amp;#34;,&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="yaml-configuration">yaml configuration&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-yaml" data-lang="yaml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">dubbo&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">application&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">name&lt;/span>: dubbo-springboot-demo-provider
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">protocol&lt;/span>:
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">name&lt;/span>: tri
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">port&lt;/span>: -&lt;span style="color:#2aa198">1&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">ext-protocol&lt;/span>: dubbo,
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="properties-configuration">properties configuration&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-properties" data-lang="properties">&lt;span style="display:flex;">&lt;span>dubbo.protocol.name&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">tri&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>dubbo.protocol.ext-protocol&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">dubbo,&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>dubbo.protocol.port&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">20880&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="qos-access">Qos access&lt;/h3>
&lt;h4 id="qos-module-import">Qos module import&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.apache.dubbo&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>dubbo-qos&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>After importing the Qos module, related configuration items can be configured by referring to &lt;a href="https://dubbo.apache.org/zh-cn/overview/mannual/java-sdk/reference-manual/qos/overview/">Qos Operation Manual&lt;/a> .&lt;/p>
&lt;p>By default, the Qos service based on port multiplexing is started after the module is imported.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="qos-used">Qos used&lt;/h3>
&lt;p>When the Qos protocol is connected to the port multiplexing scenario, after the connection is established, the client needs to send a message to the server first. Compared with the Qos protocol that provides services through a single port, the port multiplexing version of the Qos protocol handles the telnet connection. In some cases, the user needs to perform some operations to complete the protocol identification (choose one of the two).&lt;/p>
&lt;ol>
&lt;li>
&lt;p>Call the command directly&lt;/p>
&lt;p>The recognition can also be completed by directly calling the commands supported by telnet. If the user is not familiar with it, the help command can be called to complete the recognition.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/pu-server/qos-telnet-directcall.png" alt="pu-server-image2">&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Send telnet command to identify&lt;/p>
&lt;p>After establishing a connection through the telnet command, perform the following steps:&lt;/p>
&lt;ol>
&lt;li>Use crtl + &amp;ldquo;]&amp;rdquo; to enter the telnet interactive interface (telnet default escape character)&lt;/li>
&lt;li>Call &amp;ldquo;send ayt&amp;rdquo; to send a special identification field to the server (a special field of the telnet protocol)&lt;/li>
&lt;li>Press Enter to complete the message sending and enter the interactive interface of dubbo&lt;/li>
&lt;/ol>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/pu-server/qos-telnet-sendayt.png" alt="pu-server-imgs3">&lt;/p>
&lt;/li>
&lt;/ol>
&lt;h3 id="service-reference">Service reference&lt;/h3>
&lt;p>Based on the example in &lt;a href="https://github.com/apache/dubbo-samples/tree/master/3-extensions/protocol/dubbo-samples-port-unification">dubbo-samples-port-unification&lt;/a>, quote The configuration of services of different protocols and non-port multiplexing is consistent. Next, the URL information in the calling process is output through the InvokerListener on the Consumer side.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GreetingService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reference &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>GreetingService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setListener&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;consumer&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setProtocol&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span>protocol&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// reference.setProtocol(CommonConstants.DUBBO);
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// reference.setProtocol(CommonConstants.TRIPLE);
&lt;/span>&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/pu-server/reference-service.png" alt="pu-server-imgs4">&lt;/p></description></item><item><title>Docs3-V2: Reactive Programming</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/reactive/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/reactive/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>This feature is implemented based on the Triple protocol and Project Reactor, and is supported in versions above &lt;code>3.1.0&lt;/code>. Users only need to write the IDL file and specify the corresponding Generator of the protobuf plug-in to generate and use the Stub code that supports the responsive API.&lt;/p>
&lt;p>There are four call modes, namely OneToOne, OneToMany, ManyToOne, and ManyToMany, corresponding to Unary calls, server streams, client streams, and bidirectional streams. In the implementation of Reactor, One corresponds to Mono, and Many corresponds to Flux.&lt;/p>
&lt;h4 id="background">background&lt;/h4>
&lt;p>Reactive Stream provides a set of standard asynchronous stream processing APIs. While allowing applications to write event-driven programs, it also ensures node stability through BackPressure. The Triple protocol adds support for streaming scenarios to the Dubbo framework at the communication protocol level. On this basis, it can realize the business requirements of the upper layer including large file transmission and push mechanisms.&lt;/p>
&lt;p>The combined mode of Dubbo + Reactive Stream Stub can bring users the most convenient way of streaming and improve the asynchronous performance of the whole link.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>[https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-triple-reactor](&lt;a href="https://github.com/apache/dubbo-samples/tree/master/3-extensions/">https://github.com/apache/dubbo-samples/tree/master/3-extensions/&lt;/a> protocol/dubbo-samples-triple-reactor)&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>The system needs to handle a large number of concurrent requests without overloading any servers. Systems with large numbers of users providing real-time data and want to ensure that the system can handle the load without crashing or slowing down.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>For Triple usage and configuration, please refer to &lt;a href="https://dubbo.apache.org/zh-cn/overview/mannual/java-sdk/reference-manual/protocol/triple/idl/">Using Triple in IDL&lt;/a>, and ensure that the Dubbo version&amp;gt; = 3.1.0.&lt;/p>
&lt;h3 id="add-the-necessary-dependencies">Add the necessary dependencies&lt;/h3>
&lt;p>To use Reactor Triple, you need to add the following additional dependencies.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.reactivestreams&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>reactive-streams&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>io.projectreactor&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>reactor-core&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="setup-protobuf-maven-plugin">Setup protobuf Maven plugin&lt;/h3>
&lt;p>Just change mainClass to &lt;code>org.apache.dubbo.gen.tri.reactive.ReactorDubbo3TripleGenerator&lt;/code> and make sure &lt;code>${compiler.version}&lt;/code> &amp;gt;= 3.1.0&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;build&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;plugins&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;plugin&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.xolstice.maven.plugins&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>protobuf-maven-plugin&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>0.6.1&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;configuration&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;protocArtifact&amp;gt;&lt;/span>com.google.protobuf:protoc:${protoc.version}:exe:${os.detected.classifier}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/protocArtifact&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;pluginId&amp;gt;&lt;/span>grpc-java&lt;span style="color:#268bd2">&amp;lt;/pluginId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;pluginArtifact&amp;gt;&lt;/span>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/pluginArtifact&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;protocPlugins&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;protocPlugin&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;id&amp;gt;&lt;/span>dubbo&lt;span style="color:#268bd2">&amp;lt;/id&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.apache.dubbo&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>dubbo-compiler&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>${compiler.version}&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;mainClass&amp;gt;&lt;/span>org.apache.dubbo.gen.tri.reactive.ReactorDubbo3TripleGenerator&lt;span style="color:#268bd2">&amp;lt;/mainClass&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/protocPlugin&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/protocPlugins&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/configuration&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;executions&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;execution&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;goals&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;goal&amp;gt;&lt;/span>compile&lt;span style="color:#268bd2">&amp;lt;/goal&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/goals&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/execution&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/executions&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/plugin&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/plugins&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/build&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="write-and-compile-the-idl-file">Write and compile the IDL file&lt;/h3>
&lt;p>The writing of the IDL file is completely consistent with the native Triple protocol, and the corresponding code will be seen in the &lt;code>target/generated-sources/protobuf/java&lt;/code> directory by default after compilation.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-protobuf" data-lang="protobuf">&lt;span style="display:flex;">&lt;span>syntax &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;proto3&amp;#34;&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">option&lt;/span> java_multiple_files &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#cb4b16">true&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org&lt;span style="color:#719e07">.&lt;/span>apache.dubbo.samples.triple.reactor;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// The request message containing the user&amp;#39;s name.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">message&lt;/span> &lt;span style="color:#268bd2">GreeterRequest&lt;/span> {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">string&lt;/span> name &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">1&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// The response message containing the greetings
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">message&lt;/span> &lt;span style="color:#268bd2">GreeterReply&lt;/span> {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">string&lt;/span> &lt;span style="color:#268bd2">message&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">1&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">service&lt;/span> GreeterService {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">rpc&lt;/span> greetOneToOne(GreeterRequest) &lt;span style="color:#719e07">returns&lt;/span> (GreeterReply);
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">rpc&lt;/span> greetOneToMany(GreeterRequest) &lt;span style="color:#719e07">returns&lt;/span> (stream GreeterReply);
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">rpc&lt;/span> greetManyToOne(stream GreeterRequest) &lt;span style="color:#719e07">returns&lt;/span> (GreeterReply);
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">rpc&lt;/span> greetManyToMany(stream GreeterRequest) &lt;span style="color:#719e07">returns&lt;/span> (stream GreeterReply);
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="use">use&lt;/h3>
&lt;ol>
&lt;li>Add server interface implementation&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org.apache.dubbo.samples.triple.reactor.impl&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.samples.triple.reactor.DubboGreeterServiceTriple&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.samples.triple.reactor.GreeterReply&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.samples.triple.reactor.GreeterRequest&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.slf4j.Logger&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.slf4j.LoggerFactory&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> reactor.core.publisher.Flux&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">GreeterServiceImpl&lt;/span> &lt;span style="color:#268bd2">extends&lt;/span> DubboGreeterServiceTriple&lt;span style="color:#719e07">.&lt;/span>GreeterServiceImplBase &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> Logger LOGGER &lt;span style="color:#719e07">=&lt;/span> LoggerFactory&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getLogger&lt;/span>&lt;span style="color:#719e07">(&lt;/span>GreeterServiceImpl&lt;span style="color:#719e07">.&lt;/span> class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Flux&lt;span style="color:#719e07">&amp;lt;&lt;/span>GreeterReply&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">greetManyToMany&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Flux&lt;span style="color:#719e07">&amp;lt;&lt;/span>GreeterRequest&lt;span style="color:#719e07">&amp;gt;&lt;/span> request&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> request&lt;span style="color:#719e07">.&lt;/span>doOnNext&lt;span style="color:#719e07">(&lt;/span>req &lt;span style="color:#719e07">-&amp;gt;&lt;/span> LOGGER&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;greetManyToMany get data: {}&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> req&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>map&lt;span style="color:#719e07">(&lt;/span>req &lt;span style="color:#719e07">-&amp;gt;&lt;/span> GreeterReply&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">newBuilder&lt;/span>&lt;span style="color:#719e07">().&lt;/span> setMessage&lt;span style="color:#719e07">(&lt;/span>req&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getName&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#2aa198">&amp;#34; -&amp;gt; server get&amp;#34;&lt;/span>&lt;span style="color:#719e07">).&lt;/span> build&lt;span style="color:#719e07">())&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>doOnNext&lt;span style="color:#719e07">(&lt;/span>res &lt;span style="color:#719e07">-&amp;gt;&lt;/span> LOGGER&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;greetManyToMany response data: {}&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> res&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="2">
&lt;li>Add the server interface startup class&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org.apache.dubbo.samples.triple.reactor&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.common.constants.CommonConstants&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.ApplicationConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.ProtocolConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.RegistryConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.ServiceConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.bootstrap.DubboBootstrap&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.samples.triple.reactor.impl.GreeterServiceImpl&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">ReactorServer&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> PORT &lt;span style="color:#719e07">=&lt;/span> 50052&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GreeterService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reactorService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> reactorService&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>GreeterService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> reactorService&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> GreeterServiceImpl&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> DubboBootstrap bootstrap &lt;span style="color:#719e07">=&lt;/span> DubboBootstrap&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getInstance&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> bootstrap&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">application&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;tri-reactor-stub-server&amp;#34;&lt;/span>&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>registry&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> RegistryConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>protocol&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>CommonConstants&lt;span style="color:#719e07">.&lt;/span>TRIPLE&lt;span style="color:#719e07">,&lt;/span> PORT&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>service&lt;span style="color:#719e07">(&lt;/span>reactorService&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="3">
&lt;li>Add client startup class and consumer program&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org.apache.dubbo.samples.triple.reactor&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.common.constants.CommonConstants&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.ApplicationConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.ReferenceConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.RegistryConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.config.bootstrap.DubboBootstrap&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.slf4j.Logger&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.slf4j.LoggerFactory&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> reactor.core.publisher.Flux&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> reactor.core.publisher.Mono&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.io.IOException&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">ReactorConsumer&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> Logger LOGGER &lt;span style="color:#719e07">=&lt;/span> LoggerFactory&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getLogger&lt;/span>&lt;span style="color:#719e07">(&lt;/span>ReactorConsumer&lt;span style="color:#719e07">.&lt;/span> class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> GreeterService greeterService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">ReactorConsumer&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GreeterService&lt;span style="color:#719e07">&amp;gt;&lt;/span> referenceConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>GreeterService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setProtocol&lt;span style="color:#719e07">(&lt;/span>CommonConstants&lt;span style="color:#719e07">.&lt;/span>TRIPLE&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setProxy&lt;span style="color:#719e07">(&lt;/span>CommonConstants&lt;span style="color:#719e07">.&lt;/span>NATIVE_STUB&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setTimeout&lt;span style="color:#719e07">(&lt;/span>10000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> DubboBootstrap bootstrap &lt;span style="color:#719e07">=&lt;/span> DubboBootstrap&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getInstance&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> bootstrap&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">application&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;tri-reactor-stub-server&amp;#34;&lt;/span>&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>registry&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> RegistryConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>reference&lt;span style="color:#719e07">(&lt;/span>referenceConfig&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> GreeterService greeterService &lt;span style="color:#719e07">=&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> IOException &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ReactorConsumer reactorConsumer &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReactorConsumer&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> reactorConsumer&lt;span style="color:#719e07">.&lt;/span>consumeManyToMany&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>in&lt;span style="color:#719e07">.&lt;/span>read&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">consumeManyToMany&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> greeterService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">greetManyToMany&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Flux&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">range&lt;/span>&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">,&lt;/span> 10&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>map&lt;span style="color:#719e07">(&lt;/span>num&lt;span style="color:#719e07">-&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> GreeterRequest&lt;span style="color:#719e07">.&lt;/span>newBuilder&lt;span style="color:#719e07">().&lt;/span>setName&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">.&lt;/span>valueOf&lt;span style="color:#719e07">(&lt;/span>num&lt;span style="color:#719e07">)).&lt;/span>build&lt;span style="color:#719e07">())&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>doOnNext&lt;span style="color:#719e07">(&lt;/span>req &lt;span style="color:#719e07">-&amp;gt;&lt;/span> LOGGER&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;consumeManyToMany request data: {}&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> req&lt;span style="color:#719e07">)))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>subscribe&lt;span style="color:#719e07">(&lt;/span>res &lt;span style="color:#719e07">-&amp;gt;&lt;/span> LOGGER&lt;span style="color:#719e07">.&lt;/span>info&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;consumeManyToMany get response: {}&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> res&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="4">
&lt;li>
&lt;p>Start the server&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Start the consumer&lt;/p>
&lt;/li>
&lt;/ol></description></item><item><title>Docs3-V2: Service Version</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-versions/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-versions/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>&lt;strong>Follow the steps below for version migration&lt;/strong>&lt;/p>
&lt;ol>
&lt;li>During low-stress periods, first upgrade half of the providers to the new version&lt;/li>
&lt;li>Upgrade all consumers to the new version&lt;/li>
&lt;li>Then upgrade the remaining half of the providers to the new version&lt;/li>
&lt;/ol>
&lt;h4 id="configuration">Configuration&lt;/h4>
&lt;ul>
&lt;li>Old and new versions of service providers&lt;/li>
&lt;li>New and old version service consumers&lt;/li>
&lt;/ul>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When an interface is implemented and an incompatible upgrade occurs, the version number can be used for transition, and services with different version numbers do not refer to each other.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-version">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-version&lt;/a>&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="service-provider">service provider&lt;/h3>
&lt;p>Old version service provider configuration&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>New Version Service Provider Configuration&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;2.0.0&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer">Service Consumer&lt;/h3>
&lt;p>Old version service consumer configuration&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;barService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>New Version Service Consumer Configuration&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;barService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;2.0.0&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="does-not-distinguish-between-versions">Does not distinguish between versions&lt;/h3>
&lt;p>If you don&amp;rsquo;t need to distinguish between versions, you can configure it in the following way&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;barService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Cluster Fault Tolerance</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/fault-tolerent-strategy/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/fault-tolerent-strategy/</guid><description>
&lt;p>When the cluster call fails, Dubbo provides a variety of fault tolerance schemes, and the default is failover retry.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/cluster.jpg" alt="cluster">&lt;/p>
&lt;p>Each node relationship:&lt;/p>
&lt;ul>
&lt;li>Here &lt;code>Invoker&lt;/code> is an abstraction of &lt;code>Provider&lt;/code> that can call &lt;code>Service&lt;/code>, &lt;code>Invoker&lt;/code> encapsulates &lt;code>Provider&lt;/code> address and &lt;code>Service&lt;/code> interface information&lt;/li>
&lt;li>&lt;code>Directory&lt;/code> represents multiple &lt;code>Invoker&lt;/code>, which can be regarded as &lt;code>List&amp;lt;Invoker&amp;gt;&lt;/code>, but different from &lt;code>List&lt;/code>, its value may change dynamically, such as the registration center pushing changes&lt;/li>
&lt;li>&lt;code>Cluster&lt;/code> disguises multiple &lt;code>Invoker&lt;/code> in &lt;code>Directory&lt;/code> as an &lt;code>Invoker&lt;/code>, which is transparent to the upper layer. The masquerading process includes fault-tolerant logic. After the call fails, try another one&lt;/li>
&lt;li>&lt;code>Router&lt;/code> is responsible for selecting subsets from multiple &lt;code>Invoker&lt;/code> according to routing rules, such as read-write separation, application isolation, etc.&lt;/li>
&lt;li>&lt;code>LoadBalance&lt;/code> is responsible for selecting a specific one from multiple &lt;code>Invoker&lt;/code>s for this call. The selection process includes a load balancing algorithm. After the call fails, it needs to be re-selected&lt;/li>
&lt;/ul>
&lt;h2 id="cluster-fault-tolerance-mode">Cluster fault tolerance mode&lt;/h2>
&lt;p>You can expand the cluster fault-tolerant strategy by yourself, see: &lt;a href="../../../reference-manual/spi/description/cluster/">Cluster Expansion&lt;/a>&lt;/p>
&lt;h3 id="failover-cluster">Failover Cluster&lt;/h3>
&lt;p>Automatic switching on failure, when a failure occurs, retry other servers. Usually used for read operations, but retries can introduce longer delays. The number of retries can be set by &lt;code>retries=&amp;quot;2&amp;quot;&lt;/code> (excluding the first time).&lt;/p>
&lt;p>The number of retries is configured as follows:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> retries=&lt;span style="color:#2aa198">&amp;#34;2&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>or&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> retries=&lt;span style="color:#2aa198">&amp;#34;2&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>or&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;findFoo&amp;#34;&lt;/span> retries=&lt;span style="color:#2aa198">&amp;#34;2&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>
&lt;div class="alert alert-primary" role="alert">
&lt;h4 class="alert-heading">Prompt&lt;/h4>
This configuration is the default configuration
&lt;/div>
&lt;h3 id="failfast-cluster">Failfast Cluster&lt;/h3>
&lt;p>Fail fast, only one call is made, and an error will be reported immediately if it fails. Usually used for non-idempotent write operations, such as adding new records.&lt;/p>
&lt;h3 id="failsafe-cluster">Failsafe Cluster&lt;/h3>
&lt;p>Fail safe, when an exception occurs, just ignore it. Typically used for operations such as writing to audit logs.&lt;/p>
&lt;h3 id="failback-cluster">Failback Cluster&lt;/h3>
&lt;p>The failure is automatically recovered, and the failed request is recorded in the background and resent at regular intervals. Typically used for message notification operations.&lt;/p>
&lt;h3 id="forking-cluster">Forking Cluster&lt;/h3>
&lt;p>Call multiple servers in parallel, and return as long as one succeeds. It is usually used for read operations with high real-time requirements, but more service resources need to be wasted. The maximum parallelism can be set by &lt;code>forks=&amp;quot;2&amp;quot;&lt;/code>.&lt;/p>
&lt;h3 id="broadcast-cluster">Broadcast Cluster&lt;/h3>
&lt;p>Broadcast calls all providers one by one, and if any one reports an error, it will report an error. Usually used to notify all providers to update local resource information such as cache or logs.&lt;/p>
&lt;p>Now in the broadcast call, you can configure the failure ratio of the node call through broadcast.fail.percent. When this ratio is reached, the BroadcastClusterInvoker
No other nodes will be called, and an exception will be thrown directly. broadcast.fail.percent ranges from 0 to 100. By default, an exception is thrown when all calls fail.
broadcast.fail.percent only controls whether to continue to call other nodes after failure, and does not change the result (if any node reports an error, it will report an error). broadcast.fail.percent parameter
Effective in dubbo2.7.10 and above.&lt;/p>
&lt;p>Broadcast Cluster configuration broadcast.fail.percent.&lt;/p>
&lt;p>broadcast.fail.percent=20 means that when 20% of the nodes fail to call, an exception will be thrown, and no other nodes will be called.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-text" data-lang="text">&lt;span style="display:flex;">&lt;span>@reference(cluster = &amp;#34;broadcast&amp;#34;, parameters = {&amp;#34;broadcast. fail. percent&amp;#34;, &amp;#34;20&amp;#34;})
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>
&lt;div class="alert alert-primary" role="alert">
&lt;h4 class="alert-heading">Prompt&lt;/h4>
&lt;code>2.1.0&lt;/code> started to support
&lt;/div>
&lt;h3 id="available-cluster">Available Cluster&lt;/h3>
&lt;p>Calls the currently available instance (only one is called), or throws an exception if no instance is currently available. Usually used in scenarios that do not require load balancing.&lt;/p>
&lt;h3 id="mergeable-cluster">Mergeable Cluster&lt;/h3>
&lt;p>Aggregate the call results in the cluster and return the result, usually used together with group. Aggregate the results by grouping and return the aggregated results, such as menu services, use group to distinguish multiple implementations of the same interface, now the consumer needs to call once from each group and return the results, and return the results after merging, so that You can implement aggregated menu items.&lt;/p>
&lt;h3 id="zoneaware-cluster">ZoneAware Cluster&lt;/h3>
&lt;p>In the scenario of multi-registry subscription, load balancing between registry clusters. There are four strategies for address selection between multiple registries:&lt;/p>
&lt;ol>
&lt;li>Specify the priority: &lt;code>preferred=&amp;quot;true&amp;quot;&lt;/code>The address of the registration center will be selected first&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span> preferred=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="2">
&lt;li>Same center priority: check the area to which the current request belongs, and give priority to registration centers with the same area&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span> zone=&lt;span style="color:#2aa198">&amp;#34;beijing&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="3">
&lt;li>Weight polling: distribute traffic according to the weight of each registry&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;beijing&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span> weight=&lt;span style="color:#2aa198">&amp;#34;100&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;shanghai&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2182&amp;#34;&lt;/span> weight=&lt;span style="color:#2aa198">&amp;#34;10&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="4">
&lt;li>Default: Select an available registry&lt;/li>
&lt;/ol>
&lt;h2 id="cluster-mode-configuration">Cluster mode configuration&lt;/h2>
&lt;p>Follow the example below to configure cluster mode on the service provider and consumer&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> cluster=&lt;span style="color:#2aa198">&amp;#34;failsafe&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>or&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> cluster=&lt;span style="color:#2aa198">&amp;#34;failsafe&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Parameter Validation</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/parameter-validation/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/parameter-validation/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The parameter verification function is implemented based on &lt;a href="https://jcp.org/en/jsr/detail?id=303">JSR303&lt;/a>, users only need to identify the verification annotation of the JSR303 standard, and realize the verification by declaring the filter.&lt;/p>
&lt;h4 id="maven-dependencies">Maven dependencies&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>javax.validation&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>validation-api&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>1.0.0.GA&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.hibernate&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>hibernate-validator&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>4.2.0.Final&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When the server provides interface services to the outside, it solves various interface parameter verification problems.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-validation">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-validation&lt;/a>&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="parameter-annotation-example">Parameter annotation example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.io.Serializable&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.util.Date&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Future&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Max&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Min&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.NotNull&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Past&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Pattern&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Size&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">ValidationParameter&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> Serializable &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> &lt;span style="color:#dc322f">long&lt;/span> serialVersionUID &lt;span style="color:#719e07">=&lt;/span> 7158911668568000392L&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@NotNull&lt;/span> &lt;span style="color:#586e75">// not allowed to be null
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Size&lt;/span>&lt;span style="color:#719e07">(&lt;/span>min &lt;span style="color:#719e07">=&lt;/span> 1&lt;span style="color:#719e07">,&lt;/span> max &lt;span style="color:#719e07">=&lt;/span> 20&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#586e75">// length or size range
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> String name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@NotNull&lt;/span>&lt;span style="color:#719e07">(&lt;/span>groups &lt;span style="color:#719e07">=&lt;/span> ValidationService&lt;span style="color:#719e07">.&lt;/span>Save&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#586e75">// It is not allowed to be empty when saving, and it is allowed to be empty when updating, indicating that the field will not be updated
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Pattern&lt;/span>&lt;span style="color:#719e07">(&lt;/span>regexp &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;^\\s*\\w+(?:\\.{0,1}[\\w-]+)*@[a-zA-Z0-9]+(?:[- .][a-zA-Z0-9]+)*\\.[a-zA-Z]+\\s*$&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> String email&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Min&lt;/span>&lt;span style="color:#719e07">(&lt;/span>18&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#586e75">// minimum value
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Max&lt;/span>&lt;span style="color:#719e07">(&lt;/span>100&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#586e75">// maximum value
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Past&lt;/span> &lt;span style="color:#586e75">// must be a past time
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> Date loginDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Future&lt;/span> &lt;span style="color:#586e75">// must be a future time
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> Date expiryDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">getName&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setName&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span>name &lt;span style="color:#719e07">=&lt;/span> name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">getEmail&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> email&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setEmail&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String email&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span>email &lt;span style="color:#719e07">=&lt;/span> email&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> &lt;span style="color:#268bd2">getAge&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setAge&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#dc322f">int&lt;/span> age&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span> age &lt;span style="color:#719e07">=&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Date &lt;span style="color:#268bd2">getLoginDate&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> loginDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setLoginDate&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Date loginDate&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span> loginDate &lt;span style="color:#719e07">=&lt;/span> loginDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Date &lt;span style="color:#268bd2">getExpiryDate&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> expiryDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setExpiryDate&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Date expiryDate&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span>expiryDate &lt;span style="color:#719e07">=&lt;/span> expiryDate&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="group-verification-example">Group verification example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">ValidationService&lt;/span> &lt;span style="color:#719e07">{&lt;/span> &lt;span style="color:#586e75">// By default, validation scenarios can be distinguished by service interface, such as: @NotNull(groups = ValidationService.class)
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@interface&lt;/span> Save&lt;span style="color:#719e07">{}&lt;/span> &lt;span style="color:#586e75">// The interface with the same name as the method, the first letter is capitalized, used to distinguish validation scenarios, such as: @NotNull(groups = ValidationService.Save.class), optional
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">save&lt;/span>&lt;span style="color:#719e07">(&lt;/span>ValidationParameter parameter&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">update&lt;/span>&lt;span style="color:#719e07">(&lt;/span>ValidationParameter parameter&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="association-validation-example">Association Validation Example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.GroupSequence&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">ValidationService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@GroupSequence&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Update&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#586e75">// Verify Update group rules at the same time
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@interface&lt;/span> Save&lt;span style="color:#719e07">{}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">save&lt;/span>&lt;span style="color:#719e07">(&lt;/span>ValidationParameter parameter&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@interface&lt;/span> Update&lt;span style="color:#719e07">{}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">update&lt;/span>&lt;span style="color:#719e07">(&lt;/span>ValidationParameter parameter&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="parameter-validation-example">Parameter validation example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.Min&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.constraints.NotNull&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">ValidationService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">save&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#268bd2">@NotNull&lt;/span> ValidationParameter parameter&lt;span style="color:#719e07">);&lt;/span> &lt;span style="color:#586e75">// validation parameter is not empty
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">delete&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#268bd2">@Min&lt;/span>&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> id&lt;span style="color:#719e07">);&lt;/span> &lt;span style="color:#586e75">// directly verify the basic type parameters
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="validate-parameters-on-the-client-side">Validate parameters on the client side&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;validationService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.examples.validation.api.ValidationService&amp;#34;&lt;/span> validation=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="validate-parameters-on-the-server-side">Validate parameters on the server side&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.examples.validation.api.ValidationService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;validationService&amp;#34;&lt;/span> validation=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;blockquote>
&lt;p>&lt;strong>Dubbo supports hibernate-validator version &amp;lt;=6.x by default, if you use hibernate-validator 7.x version, please declare the validation parameter as jvalidatorNew&lt;/strong>&lt;/p>
&lt;/blockquote>
&lt;h3 id="verify-exception-information">Verify exception information&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.ConstraintViolationException&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> javax.validation.ConstraintViolationException&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.springframework.context.support.ClassPathXmlApplicationContext&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.examples.validation.api.ValidationParameter&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.examples.validation.api.ValidationService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> org.apache.dubbo.rpc.RpcException&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">ValidationConsumer&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> Exception &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String config &lt;span style="color:#719e07">=&lt;/span> ValidationConsumer&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">.&lt;/span>getPackage&lt;span style="color:#719e07">().&lt;/span>getName&lt;span style="color:#719e07">().&lt;/span>replace&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#39;.&amp;#39;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#39;/&amp;#39;&lt;/span>&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#2aa198">&amp;#34;/validation-consumer.xml&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ClassPathXmlApplicationContext context &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ClassPathXmlApplicationContext&lt;span style="color:#719e07">(&lt;/span>config&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">start&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ValidationService validationService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>ValidationService&lt;span style="color:#719e07">)&lt;/span>context&lt;span style="color:#719e07">.&lt;/span>getBean&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;validationService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Error
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> parameter &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ValidationParameter&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> validationService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">save&lt;/span>&lt;span style="color:#719e07">(&lt;/span>parameter&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Validation ERROR&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>RpcException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span> &lt;span style="color:#586e75">// What is thrown is RpcException
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ConstraintViolationException ve &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>ConstraintViolationException&lt;span style="color:#719e07">)&lt;/span> e&lt;span style="color:#719e07">.&lt;/span>getCause&lt;span style="color:#719e07">();&lt;/span> &lt;span style="color:#586e75">// A ConstraintViolationException is embedded in it
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> Set&lt;span style="color:#719e07">&amp;lt;&lt;/span>ConstraintViolation&lt;span style="color:#719e07">&amp;lt;?&amp;gt;&amp;gt;&lt;/span> violations &lt;span style="color:#719e07">=&lt;/span> ve&lt;span style="color:#719e07">.&lt;/span>getConstraintViolations&lt;span style="color:#719e07">();&lt;/span> &lt;span style="color:#586e75">// You can get a collection of verification error details
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>violations&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;blockquote>
&lt;p>&lt;strong>The validation method can be extended, see &lt;a href="../../../reference-manual/spi/description/validation">Validation Extension&lt;/a> in the developer manual for the extension method&lt;/strong>&lt;/p>
&lt;/blockquote></description></item><item><title>Docs3-V2: Service Group</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/service-group/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/service-group/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The same interface can use service grouping to distinguish different implementation methods for different business scenarios, different usage requirements, or different functional modules. At the same time, the services provided by these different implementations can coexist and support mutual calls.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When an interface has multiple implementations, it can be distinguished by group.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-group">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-group&lt;/a>&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="annotation-configuration">Annotation configuration&lt;/h3>
&lt;h4 id="service-provider-annotation-configuration">Service provider (annotation configuration)&lt;/h4>
&lt;p>Use @DubboService annotation, add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@DubboService&lt;/span>&lt;span style="color:#719e07">(&lt;/span>group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">DemoServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> DemoService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@DubboService&lt;/span>&lt;span style="color:#719e07">(&lt;/span>group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">Demo2ServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> DemoService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Start the Dubbo service, and you can see services with the same service name and different groups in the registry. Taking Nacos as the registry as an example, the following content is displayed:&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-1.png" alt="image-service-group-1.png">&lt;/p>
&lt;h4 id="service-consumer-annotation-configuration">Service consumer (annotation configuration)&lt;/h4>
&lt;p>Use @DubboReference annotation to add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@DubboReference&lt;/span>&lt;span style="color:#719e07">(&lt;/span>group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">private&lt;/span> DemoService demoService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@DubboReference&lt;/span>&lt;span style="color:#719e07">(&lt;/span>group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">private&lt;/span> DemoService demoService2&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">//group value is *, the identifier matches any service group
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">@DubboReference&lt;/span>&lt;span style="color:#719e07">(&lt;/span>group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">private&lt;/span> DemoService demoService2&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>After starting the Dubbo service, you can see the references of the same service name in different groups in the registration center. Taking Nacos as the registration center as an example, the following content is displayed:
&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-2.png" alt="image-service-group-2.png">&lt;/p>
&lt;h3 id="xml-configuration">xml configuration&lt;/h3>
&lt;h4 id="service-provider-xml-configuration">Service provider (xml configuration)&lt;/h4>
&lt;p>Use &amp;lt;dubbo:service /&amp;gt; tag, add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://dubbo.apache.org/schema/dubbo
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>...
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.example.service.DemoService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.example.service.DemoService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>...
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Start the Dubbo service, and you can see services with the same service name and different groups in the registry. Taking Nacos as the registry as an example, the following content is displayed:&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-1.png" alt="image-service-group-1.png">&lt;/p>
&lt;h4 id="service-consumer-xml-configuration">Service consumer (xml configuration)&lt;/h4>
&lt;p>Use &lt;a href="dubbo:reference/">dubbo:reference/&lt;/a> annotation to add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://dubbo.apache.org/schema/dubbo
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ...
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- reference service interface --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.example.service.DemoService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService2&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.example.service.DemoService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- The group value is *, and the identifier matches any service group --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService3&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.example.service.DemoService&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ...
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>After starting the Dubbo service, you can see the references of the same service name in different groups in the registration center. Taking Nacos as the registration center as an example, the following content is displayed:&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-2.png" alt="image-service-group-2.png">&lt;/p>
&lt;h3 id="api-configuration">API configuration&lt;/h3>
&lt;h4 id="service-provider-api-configuration">Service provider (API configuration)&lt;/h4>
&lt;p>Use org.apache.dubbo.config.ServiceConfig class, add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// ServiceConfig is a heavy object, which internally encapsulates the connection with the registration center and opens the service port
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Please cache by yourself, otherwise it may cause memory and connection leaks
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> service &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service&lt;span style="color:#719e07">.&lt;/span>setGroup&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> service2 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service&lt;span style="color:#719e07">.&lt;/span>setGroup&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Start the Dubbo service, and you can see services with the same service name and different groups in the registry. Taking Nacos as the registry as an example, the following content is displayed:&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-1.png" alt="image-service-group-1.png">&lt;/p>
&lt;h4 id="service-consumer-api-configuration">Service consumer (API configuration)&lt;/h4>
&lt;p>Use org.apache.dubbo.config.ReferenceConfig, add group parameter&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// ReferenceConfig is a heavy object, which internally encapsulates the connection with the registration center and opens the service port
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Please cache by yourself, otherwise it may cause memory and connection leaks
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reference &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setGroup&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demo&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reference2 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference2&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference2&lt;span style="color:#719e07">.&lt;/span>setGroup&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demo2&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reference3 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference3&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference3&lt;span style="color:#719e07">.&lt;/span>setGroup&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;*&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>After starting the Dubbo service, you can see the references of the same service name in different groups in the registration center. Taking Nacos as the registration center as an example, the following content is displayed:
&lt;img src="https://dubbo.apache.org/imgs/blog/service-group-2.png" alt="image-service-group-2.png">&lt;/p>
&lt;blockquote>
&lt;p>Always &lt;em>call&lt;/em>* only one available group implementation&lt;/p>
&lt;/blockquote></description></item><item><title>Docs3-V2: Asynchronous call</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/async-call/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/async-call/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;h4 id="background">background&lt;/h4>
&lt;p>Starting from 2.7.0, all asynchronous programming interfaces of Dubbo are based on &lt;a href="https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletableFuture.html">CompletableFuture&lt;/a>&lt;/p>
&lt;p>Based on NIO&amp;rsquo;s non-blocking implementation of parallel calls, the client does not need to start multi-threads to complete parallel calls to multiple remote services, and the overhead of multi-threading is relatively small.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/future.jpg" alt="/user-guide/images/future.jpg">&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-async">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-async&lt;/a>&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Send the user request content to the target request. When the target request encounters high traffic or needs to be processed for a long time, the asynchronous call function will allow the response to be returned to the user immediately, while the target request continues to process the request in the background. When the target request returns the result, the content will be sent displayed to the user.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="interface-signed-with-completablefuture">Interface signed with CompletableFuture&lt;/h3>
&lt;p>For services that require service providers to define CompletableFuture signatures in advance, the interface definition guidelines are as follows:&lt;/p>
&lt;p>The asynchronous execution of the provider side switches the blocked business from Dubbo&amp;rsquo;s internal thread pool to the business-defined thread, avoiding excessive occupation of the Dubbo thread pool, and helping to avoid the mutual influence between different services. Asynchronous execution is tantamount to saving resources or improving RPC response performance, because if business execution needs to be blocked, there is always a thread to be responsible for execution.&lt;/p>
&lt;blockquote>
&lt;p>&lt;strong>Provider-side asynchronous execution and Consumer-side asynchronous call are independent of each other, any orthogonal combination of two configurations&lt;/strong>&lt;/p>
&lt;ul>
&lt;li>Consumer Synchronization - Provider Synchronization&lt;/li>
&lt;li>Consumer asynchronous - Provider synchronous&lt;/li>
&lt;li>Consumer synchronous - Provider asynchronous&lt;/li>
&lt;li>Consumer asynchronous - Provider asynchronous&lt;/li>
&lt;/ul>
&lt;/blockquote>
&lt;h3 id="define-the-interface-of-completablefuture-signature">Define the interface of CompletableFuture signature&lt;/h3>
&lt;p>service interface definition&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">AsyncService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>service realization&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">AsyncServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> AsyncService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> CompletableFuture&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">supplyAsync&lt;/span>&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;async response from provider.&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Through &lt;code>return CompletableFuture.supplyAsync()&lt;/code>, the business execution has been switched from the Dubbo thread to the business thread, avoiding the blocking of the Dubbo thread pool.&lt;/p>
&lt;h3 id="using-asynccontext">Using AsyncContext&lt;/h3>
&lt;p>Dubbo provides an asynchronous interface &lt;code>AsyncContext&lt;/code> similar to Servlet 3.0, which can also implement asynchronous execution on the Provider side without the CompletableFuture signature interface.&lt;/p>
&lt;p>service interface definition&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">AsyncService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Service exposure, exactly the same as ordinary services&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.governance.impl.AsyncServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.governance.api.AsyncService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>service realization&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">AsyncServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> AsyncService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">final&lt;/span> AsyncContext asyncContext &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">startAsync&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// If you want to use the context, it must be executed in the first sentence
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> asyncContext&lt;span style="color:#719e07">.&lt;/span>signalContextSwitch&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>500&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// write back the response
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> asyncContext&lt;span style="color:#719e07">.&lt;/span>write&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Hello &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#2aa198">&amp;#34;, response from provider.&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Note that the return type of the interface is &lt;code>CompletableFuture&amp;lt;String&amp;gt;&lt;/code>.&lt;/p>
&lt;p>XML Reference Service&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span> timeout=&lt;span style="color:#2aa198">&amp;#34;10000&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.dubbo.samples.async.api.AsyncService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>call remote service&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// The call directly returns CompletableFuture
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> asyncService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;async call request&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// add callback
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>future&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">whenComplete&lt;/span>&lt;span style="color:#719e07">((&lt;/span>v&lt;span style="color:#719e07">,&lt;/span> t&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">if&lt;/span> &lt;span style="color:#719e07">(&lt;/span>t &lt;span style="color:#719e07">!=&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> t&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">printStackTrace&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">else&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Response: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> v&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// earlier than the result output
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Executed before response return.&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="using-rpccontext">Using RpcContext&lt;/h3>
&lt;p>Configure in consumer.xml&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.governance.api.AsyncService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span> async=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>calling code&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// this call returns null immediately
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>asyncService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Get the Future reference of the call, when the result is returned, it will be notified and set to this Future
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> helloFuture &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>getCompletableFuture&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// add callback for Future
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>helloFuture&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">whenComplete&lt;/span>&lt;span style="color:#719e07">((&lt;/span>retValue&lt;span style="color:#719e07">,&lt;/span> exception&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">if&lt;/span> &lt;span style="color:#719e07">(&lt;/span>exception &lt;span style="color:#719e07">==&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>retValue&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">else&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> exception&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">printStackTrace&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Alternatively, it is also possible to do this asynchronously by calling&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>asyncCall&lt;span style="color:#719e07">(&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> asyncService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;oneway call request1&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>future&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;strong>Asynchronous always does not wait for return&lt;/strong>, you can also set whether to wait for the message to be sent&lt;/p>
&lt;ul>
&lt;li>&lt;code>sent=&amp;quot;true&amp;quot;&lt;/code> waits for the message to be sent, and an exception will be thrown if the message fails to be sent.&lt;/li>
&lt;li>&lt;code>sent=&amp;quot;false&amp;quot;&lt;/code> does not wait for the message to be sent, puts the message in the IO queue, and returns immediately.&lt;/li>
&lt;/ul>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;findFoo&amp;#34;&lt;/span> async=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> sent=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>If you just want to be asynchronous and completely ignore the return value, you can configure &lt;code>return=&amp;quot;false&amp;quot;&lt;/code> to reduce the cost of creating and managing Future objects&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;findFoo&amp;#34;&lt;/span> async=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> return=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Service Downgrade</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/service-downgrade/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/service-downgrade/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>It is recommended to use relevant current limiting and downgrading components (such as &lt;a href="https://sentinelguard.io/zh-cn/docs/open-source-framework-integrations.html">Sentinel&lt;/a>) to achieve the best experience. Reference example practice: &lt;a href="https://dubbo.apache.org/zh-cn/overview/tasks/ecosystem/rate-limit/">Microservice Governance/Limit and Downgrade&lt;/a>&lt;/p>
&lt;p>Service degradation refers to the emergency treatment of service degradation under abnormal circumstances.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;ul>
&lt;li>When the load of a certain service or interface exceeds the maximum carrying capacity range, downgrade emergency treatment is required to avoid system crash&lt;/li>
&lt;li>When a non-critical service or interface called is temporarily unavailable, simulated data or null is returned, and the business can continue to be available&lt;/li>
&lt;li>Downgrade non-core business services or interfaces, free up system resources, and try to ensure the normal operation of core business&lt;/li>
&lt;li>When an upstream basic service times out or is unavailable, execute a downgrade plan that can respond quickly to avoid the overall avalanche of services&lt;/li>
&lt;/ul>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>Take xml configuration as an example: (configuration through annotations is similar)&lt;/p>
&lt;h3 id="1-configure-mocktrue">1. Configure &lt;code>mock=&amp;quot;true&amp;quot;&lt;/code>&lt;/h3>
&lt;p>example:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>This method requires an implementation class with the class name + &lt;code>Mock&lt;/code> suffix under the same package, that is, there is a &lt;code>DemoServiceMock&lt;/code> class under the &lt;code>com.xxx.service&lt;/code> package.&lt;/p>
&lt;h3 id="2-configure-mockcomxxxservicedemoservicemock">2. Configure &lt;code>mock=&amp;quot;com.xxx.service.DemoServiceMock&amp;quot;&lt;/code>&lt;/h3>
&lt;p>example:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoServiceMock&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>This method specifies the full path of the Mock class.&lt;/p>
&lt;h3 id="3-configure-mockfailforcereturnthrow-xxx">3. Configure &lt;code>mock=&amp;quot;[fail|force]return|throw xxx&amp;quot;&lt;/code>&lt;/h3>
&lt;ul>
&lt;li>The fail or force keyword is optional, indicating that the call fails or does not call to enforce the mock method, if no keyword is specified, the default is fail&lt;/li>
&lt;li>return indicates the specified return result, and throw indicates that the specified exception is thrown&lt;/li>
&lt;li>xxx is parsed according to the return type of the interface, you can specify the return value or throw a custom exception&lt;/li>
&lt;/ul>
&lt;p>example:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;return&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;return null&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;fail:return aaa&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;force:return true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;fail:throw&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.service.DemoService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;force:throw java.lang.NullPointException&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="4-use-with-dubbo-admin">4. Use with dubbo-admin&lt;/h3>
&lt;ul>
&lt;li>
&lt;p>Introduce &lt;a href="https://github.com/apache/dubbo-spi-extensions/tree/master/dubbo-mock-extensions" target="_blank">&lt;code>dubbo-mock-admin&lt;/code>&amp;lt; /a&amp;gt;dependency&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Set the JVM parameters when the application consumer starts, &lt;code>-Denable.dubbo.admin.mock=true&lt;/code>&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Start dubbo-admin, set the Mock rule under the service Mock-&amp;gt;rule configuration menu&lt;/p>
&lt;/li>
&lt;/ul>
&lt;p>Set rules in the dimension of service methods, set return mock data, and dynamically enable/disable rules&lt;/p>
&lt;h2 id="precautions">Precautions&lt;/h2>
&lt;p>When Dubbo starts, it will check the configuration. When the configuration of the mock attribute value is wrong, it will fail to start. You can troubleshoot according to the error message&lt;/p>
&lt;ul>
&lt;li>
&lt;p>The configuration format is wrong, such as &lt;code>return+null&lt;/code> will report an error, and it will be treated as a mock type. &lt;code>return&lt;/code> can be omitted or followed by a space followed by the return value&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Type not found error, such as custom mock class, throw custom exception, please check if the type exists or if there is a typo&lt;/p>
&lt;/li>
&lt;/ul></description></item><item><title>Docs3-V2: Generalization call (client generalization)</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/generic-reference/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/generic-reference/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Generalized call refers to calling the server without the API (SDK) provided by the server, and the call result can be obtained normally.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>The generalization call is mainly used to implement a general remote service mock framework, which can handle all service requests by implementing the GenericService interface. For example, the following scenario:&lt;/p>
&lt;ol>
&lt;li>
&lt;p>Gateway service: If you want to build a gateway service, then the service gateway should be the calling end of all RPC services. However, the gateway itself should not depend on the interface API of the service provider (this will cause the code of the gateway to be modified and redeployed every time a new service is released), so support for generalization calls is required.&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Test platform: If you want to build a platform that can test RPC calls, the user can test the corresponding RPC service by inputting information such as group name, interface, method name, etc. Then, for the same reason (that is, every time a new service is released, the code of the gateway needs to be modified and redeployed), the platform itself should not depend on the interface API of the service provider. So support for generalized calls is needed.&lt;/p>
&lt;/li>
&lt;/ol>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>The demo can be seen &lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-generic">sample code in the dubbo project&lt;/a>&lt;/p>
&lt;p>The API part uses this demo as an example to explain how to use it.&lt;/p>
&lt;h3 id="service-definition">Service definition&lt;/h3>
&lt;h4 id="service-interface">Service interface&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">HelloService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsync&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsyncComplex&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericType&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsyncGenericComplex&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="service-implementation-class">Service implementation class&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">HelloServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> HelloService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;sayHello: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsync&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> future&lt;span style="color:#719e07">.&lt;/span>complete&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHelloAsync: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> future&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsyncComplex&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Person person &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Person&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;sayHelloAsyncComplex: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> future&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">complete&lt;/span>&lt;span style="color:#719e07">(&lt;/span>person&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> future&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericType&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHelloAsyncGenericComplex&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Person person &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Person&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;sayHelloAsyncGenericComplex: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> GenericType&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&lt;/span> genericType &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> GenericType&lt;span style="color:#719e07">&amp;lt;&amp;gt;(&lt;/span>person&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericType&lt;span style="color:#719e07">&amp;lt;&lt;/span>Person&lt;span style="color:#719e07">&amp;gt;&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> future&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">complete&lt;/span>&lt;span style="color:#719e07">(&lt;/span>genericType&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> future&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="using-generic-calls-through-the-api">Using generic calls through the API&lt;/h3>
&lt;h4 id="service-initiator">Service initiator&lt;/h4>
&lt;ol>
&lt;li>
&lt;p>When setting &lt;code>ServiceConfig&lt;/code>, use &lt;code>setGeneric(&amp;quot;true&amp;quot;)&lt;/code> to enable generic calls&lt;/p>
&lt;/li>
&lt;li>
&lt;p>When setting &lt;code>ServiceConfig&lt;/code>, when using setRef to specify the implementation class, you must set a &lt;code>GenericService&lt;/code> object. instead of the real service implementation class object&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Other settings are consistent with normal Api service startup&lt;/p>
&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> String zookeeperAddress &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;zookeeper://&amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> System&lt;span style="color:#719e07">.&lt;/span>getProperty&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;zookeeper.address&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;127.0.0.1&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#2aa198">&amp;#34;:2181&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> Exception &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Embedded &lt;span style="color:#268bd2">ZooKeeper&lt;/span>&lt;span style="color:#719e07">(&lt;/span>2181&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#cb4b16">false&lt;/span>&lt;span style="color:#719e07">).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create ApplicationConfig
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ApplicationConfig applicationConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> applicationConfig&lt;span style="color:#719e07">.&lt;/span>setName&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;generic-impl-provider&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create registry configuration
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> RegistryConfig registryConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> RegistryConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> registryConfig&lt;span style="color:#719e07">.&lt;/span>setAddress&lt;span style="color:#719e07">(&lt;/span>zookeeperAddress&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create a new service implementation class, pay attention to use GenericService to receive
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> GenericService helloService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> GenericImplOfHelloService&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create service related configuration
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;&lt;/span> service &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> service&lt;span style="color:#719e07">.&lt;/span>setApplication&lt;span style="color:#719e07">(&lt;/span>applicationConfig&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> service&lt;span style="color:#719e07">.&lt;/span>setRegistry&lt;span style="color:#719e07">(&lt;/span>registryConfig&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> service&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.generic.call.api.HelloService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> service&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>helloService&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Key point: set to generalization call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">// Note: it is no longer recommended to use the setGeneric function whose parameter is a Boolean value
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">//should use referenceConfig.setGeneric(&amp;#34;true&amp;#34;) instead
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> service&lt;span style="color:#719e07">.&lt;/span>setGeneric&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> service&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">export&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;dubbo service started&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> CountDownLatch&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">).&lt;/span> await&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="generalizing-the-caller">Generalizing the caller&lt;/h4>
&lt;p>step:&lt;/p>
&lt;ol>
&lt;li>
&lt;p>When setting &lt;code>ReferenceConfig&lt;/code>, use &lt;code>setGeneric(&amp;quot;true&amp;quot;)&lt;/code> to enable generic calls&lt;/p>
&lt;/li>
&lt;li>
&lt;p>After configuring &lt;code>ReferenceConfig&lt;/code>, use &lt;code>referenceConfig.get()&lt;/code> to get the instance of the &lt;code>GenericService&lt;/code> class&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Use its &lt;code>$invoke&lt;/code> method to get the result&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Other settings are consistent with normal Api service startup&lt;/p>
&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Define generalized call service class
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> GenericService genericService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> Exception &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create ApplicationConfig
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ApplicationConfig applicationConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> applicationConfig&lt;span style="color:#719e07">.&lt;/span>setName&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;generic-call-consumer&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create registry configuration
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> RegistryConfig registryConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> RegistryConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> registryConfig&lt;span style="color:#719e07">.&lt;/span>setAddress&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Create service reference configuration
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;&lt;/span> referenceConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Set the interface
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.generic.call.api.HelloService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> applicationConfig&lt;span style="color:#719e07">.&lt;/span>setRegistry&lt;span style="color:#719e07">(&lt;/span>registryConfig&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setApplication&lt;span style="color:#719e07">(&lt;/span>applicationConfig&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Key point: set to generalization call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">// Note: it is no longer recommended to use the setGeneric function whose parameter is a Boolean value
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">//should use referenceConfig.setGeneric(&amp;#34;true&amp;#34;) instead
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setGeneric&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Set asynchronous, not necessary, it depends on the business.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setAsync&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Set the timeout
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span>setTimeout&lt;span style="color:#719e07">(&lt;/span>7000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Get the service, because it is a generalized call, so it must be of the GenericService type
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> genericService &lt;span style="color:#719e07">=&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Using the $invoke method of the GenericService class object can be used instead of the original method
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">//The first parameter is the name of the method to call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">//The second parameter is the parameter type array of the method to be called, which is a String array, and the full class name of the parameter is stored in it.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">//The third parameter is the parameter array of the method to be called, which is an Object array, and the required parameters are stored in it.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> Object result &lt;span style="color:#719e07">=&lt;/span> genericService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">$invoke&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> String&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;java. lang. String&amp;#34;&lt;/span>&lt;span style="color:#719e07">},&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Object&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Use CountDownLatch, if you use synchronous calls, you don&amp;#39;t need to do this.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> CountDownLatch latch &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> CountDownLatch&lt;span style="color:#719e07">(&lt;/span>1&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Get the result
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> future &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getContext&lt;span style="color:#719e07">().&lt;/span>getCompletableFuture&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> future&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">whenComplete&lt;/span>&lt;span style="color:#719e07">((&lt;/span>value&lt;span style="color:#719e07">,&lt;/span> t&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>err&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;invokeSayHello(whenComplete): &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> value&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> latch&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">countDown&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// print the result
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> System&lt;span style="color:#719e07">.&lt;/span>err&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;invokeSayHello(return): &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> result&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> latch&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">await&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="using-generic-calls-with-spring">Using generic calls with Spring&lt;/h3>
&lt;p>There are many ways to use service exposure and service discovery in Spring, such as xml and annotations. Take xml as an example here.
step:&lt;/p>
&lt;ol>
&lt;li>
&lt;p>There is no need to change the producer side&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Add the attribute of &lt;code>generic=true&lt;/code> to the original &lt;code>dubbo:reference&lt;/code> tag on the consumer side.&lt;/p>
&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> generic = &lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.generic.call.api.HelloService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="3">
&lt;li>
&lt;p>Get the Bean container, and get the &lt;code>GenericService&lt;/code> instance through the Bean container.&lt;/p>
&lt;/li>
&lt;li>
&lt;p>Call the &lt;code>$invoke&lt;/code> method to get the result&lt;/p>
&lt;/li>
&lt;/ol>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> GenericService genericService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">main&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> Exception &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ClassPathXmlApplicationContext context &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ClassPathXmlApplicationContext&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;spring/generic-impl-consumer.xml&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">start&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//The name of the bean corresponding to the service is determined by the id of the xml tag
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> genericService &lt;span style="color:#719e07">=&lt;/span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">//Get the result
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> Object result &lt;span style="color:#719e07">=&lt;/span> genericService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">$invoke&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> String&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;java. lang. String&amp;#34;&lt;/span>&lt;span style="color:#719e07">},&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Object&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="protobuf-object-generalization-call">Protobuf object generalization call&lt;/h3>
&lt;p>General generalization calls can only be used when the generated service parameters are POJOs, while GoogleProtobuf objects are abnormal POJOs generated based on Builder, which can be generalized and called through protobuf-json.&lt;/p>
&lt;p>GoogleProtobuf serialization-related Demo can refer to &lt;a href="https://github.com/apache/dubbo-samples/tree/master/3-extensions/serialization/dubbo-samples-protobuf">protobuf-demo&lt;/a>&lt;/p>
&lt;h4 id="generic-calls-to-google-protobuf-objects-through-spring">Generic calls to Google Protobuf objects through Spring&lt;/h4>
&lt;p>Configure the declaration generic = &amp;ldquo;protobuf-json&amp;rdquo; in Spring&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;barService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> generic=&lt;span style="color:#2aa198">&amp;#34;protobuf-json&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Get barService in Java code and start generalizing calls:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>GenericService barService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>GenericService&lt;span style="color:#719e07">)&lt;/span> applicationContext&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;barService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>Object result &lt;span style="color:#719e07">=&lt;/span> barService&lt;span style="color:#719e07">.&lt;/span>$invoke&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>&lt;span style="color:#719e07">new&lt;/span> String&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.protobuf.GooglePbBasic$CDubboGooglePBRequestType&amp;#34;&lt;/span>&lt;span style="color:#719e07">},&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Object&lt;span style="color:#719e07">[]{&lt;/span>&lt;span style="color:#2aa198">&amp;#34;{\&amp;#34;double\&amp;#34;:0.0,\&amp;#34;float \&amp;#34;:0.0,\&amp;#34;bytesType\&amp;#34;:\&amp;#34;Base64String\&amp;#34;,\&amp;#34;int32\&amp;#34;:0}&amp;#34;&lt;/span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="generalized-calls-to-google-protobuf-objects-through-api">Generalized calls to Google Protobuf objects through API&lt;/h4>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;&lt;/span> reference &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Weakly typed interface name
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>reference&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>GenericService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">.&lt;/span>getName&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>reference&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;com.xxx.XxxService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Declare as Protobuf-json
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>reference&lt;span style="color:#719e07">.&lt;/span>setGeneric&lt;span style="color:#719e07">(&lt;/span>Constants&lt;span style="color:#719e07">.&lt;/span>GENERIC_SERIALIZATION_PROTOBUF&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>GenericService genericService &lt;span style="color:#719e07">=&lt;/span> reference&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;&lt;/span> person &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;fixed64&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;0&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;int64&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;0&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Referring to Google&amp;#39;s official protobuf 3 syntax, only one POJO object is transmitted in each method of the service
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// The generalized call of protobuf only allows passing a json object of type String to represent the request parameter
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>String requestString &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Gson&lt;span style="color:#719e07">().&lt;/span>toJson&lt;span style="color:#719e07">(&lt;/span>person&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// The return object is the json string of the GoolgeProtobuf response object.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>Object result &lt;span style="color:#719e07">=&lt;/span> genericService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">$invoke&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> String&lt;span style="color:#719e07">[]&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#2aa198">&amp;#34;com.xxx.XxxService.GooglePbBasic$CDubboGooglePBRequestType&amp;#34;&lt;/span>&lt;span style="color:#719e07">},&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Object&lt;span style="color:#719e07">[]&lt;/span> &lt;span style="color:#719e07">{&lt;/span>requestString&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="processing-of-googleprotobuf-objects">Processing of GoogleProtobuf objects&lt;/h4>
&lt;p>The GoogleProtobuf object is generated by the Protocol contract. For related knowledge, please refer to &lt;a href="https://developers.google.com/protocol-buffers/?hl=zh-CN">ProtocolBuffers Documentation&lt;/a>. If there is the following Protobuf contract&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-proto" data-lang="proto">&lt;span style="display:flex;">&lt;span>syntax &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;proto3&amp;#34;&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com&lt;span style="color:#719e07">.&lt;/span>xxx.XxxService.GooglePbBasic.basic;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">message&lt;/span> &lt;span style="color:#268bd2">CDubboGooglePBRequestType&lt;/span> {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">double&lt;/span> &lt;span style="color:#dc322f">double&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">1&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">float&lt;/span> &lt;span style="color:#dc322f">float&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">2&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">int32&lt;/span> &lt;span style="color:#dc322f">int32&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">3&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">bool&lt;/span> &lt;span style="color:#dc322f">bool&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">13&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">string&lt;/span> &lt;span style="color:#dc322f">string&lt;/span> &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">14&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">bytes&lt;/span> bytesType &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">15&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">message&lt;/span> &lt;span style="color:#268bd2">CDubboGooglePBResponseType&lt;/span> {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">string&lt;/span> msg &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">1&lt;/span>;
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">service&lt;/span> CDubboGooglePBService {
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">rpc&lt;/span> sayHello (CDubboGooglePBRequestType) &lt;span style="color:#719e07">returns&lt;/span> (CDubboGooglePBResponseType);
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>}
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Then the corresponding request is constructed according to the following method&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;&lt;/span> person &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;double&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1.000&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;float&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1.00&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;int32&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>&lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;bool&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">//String objects need to be base64 encoded
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;string&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>&lt;span style="color:#2aa198">&amp;#34;someBaseString&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>person&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;bytesType&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span>&lt;span style="color:#2aa198">&amp;#34;150&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="googleprotobuf-service-metadata-analysis">GoogleProtobuf service metadata analysis&lt;/h4>
&lt;p>Google Protobuf objects lack standard JSON formatting and the resulting service metadata information is incorrect. Please add the following dependencies that depend on metadata parsing.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.apache.dubbo&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>dubbo-metadata-definition-protobuf&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>${dubbo.version}&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>It is also relatively easy to construct generalized call objects from service metadata.&lt;/p>
&lt;h2 id="precautions">Precautions&lt;/h2>
&lt;ol>
&lt;li>
&lt;p>If the parameter is a basic type or Date, List, Map, etc., there is no need to convert it, just call it directly.&lt;/p>
&lt;/li>
&lt;li>
&lt;p>If the parameter is another POJO, use Map instead.&lt;/p>
&lt;/li>
&lt;/ol>
&lt;p>Such as:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">Student&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">int&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">getName&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setName&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span>name &lt;span style="color:#719e07">=&lt;/span> name&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> &lt;span style="color:#268bd2">getAge&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setAge&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#dc322f">int&lt;/span> age&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span> age &lt;span style="color:#719e07">=&lt;/span> age&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Should be converted to:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;&lt;/span> student &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>student&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;name&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;xxx&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>student&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;age&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;xxx&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol start="3">
&lt;li>For other serialization formats, special configuration is required&lt;/li>
&lt;/ol></description></item><item><title>Docs3-V2: Stream Communication</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/streaming/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/streaming/</guid><description>
&lt;p>TBD&lt;/p></description></item><item><title>Docs3-V2: Thread Pool Isolation</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/isolation-executor/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/isolation-executor/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>A new thread pool management method enables the thread pools of each service in the provider application to be isolated and independent from each other. The exhaustion of the thread pool resources of a certain service will not affect other normal services. Support thread pool configurable, manually specified by the user.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>Currently, it can be configured in the form of API, XML, and Annotation&lt;/p>
&lt;p>&lt;strong>Configuration parameters&lt;/strong>&lt;/p>
&lt;ul>
&lt;li>&lt;code>ApplicationConfig&lt;/code> adds &lt;code>String executor-management-mode&lt;/code> parameter, the configuration values are &lt;code>default&lt;/code> and &lt;code>isolation&lt;/code>, and the default is &lt;code>default&lt;/code>.
&lt;ul>
&lt;li>&lt;code>executor-management-mode = default&lt;/code> use the original &lt;strong>thread pool management mode with the protocol port as the granularity and sharing between services&lt;/strong>&lt;/li>
&lt;li>&lt;code>executor-management-mode = isolation&lt;/code> uses the newly added thread pool management method with &lt;strong>service triplet as granularity and isolation between services&lt;/strong>&lt;/li>
&lt;/ul>
&lt;/li>
&lt;li>&lt;code>ServiceConfig&lt;/code> adds &lt;code>Executor executor&lt;/code> parameter, &lt;strong>thread pool for isolation between services&lt;/strong>, can be configured by the user to provide the thread pool you want, if not specified, it will be configured according to the protocol (&lt;code> ProtocolConfig&lt;/code>) information to build a default thread pool for service isolation.&lt;/li>
&lt;/ul>
&lt;blockquote>
&lt;p>&lt;code>ServiceConfig&lt;/code> adds the &lt;code>Executor executor&lt;/code> configuration parameter to take effect only if &lt;code>executor-management-mode = isolation&lt;/code> is specified.&lt;/p>
&lt;/blockquote>
&lt;h3 id="apis">APIs&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">test&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// provider app
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> DubboBootstrap providerBootstrap &lt;span style="color:#719e07">=&lt;/span> DubboBootstrap&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">newInstance&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ServiceConfig serviceConfig1 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig1&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>DemoService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig1&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> DemoServiceImpl&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig1&lt;span style="color:#719e07">.&lt;/span>setVersion&lt;span style="color:#719e07">(&lt;/span>version1&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// set executor1 for serviceConfig1, max threads is 10
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> NamedThreadFactory threadFactory1 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> NamedThreadFactory&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;DemoService-executor&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ExecutorService executor1 &lt;span style="color:#719e07">=&lt;/span> Executors&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">newFixedThreadPool&lt;/span>&lt;span style="color:#719e07">(&lt;/span>10&lt;span style="color:#719e07">,&lt;/span> threadFactory1&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig1&lt;span style="color:#719e07">.&lt;/span>setExecutor&lt;span style="color:#719e07">(&lt;/span>executor1&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ServiceConfig serviceConfig2 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig2&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>HelloService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig2&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> HelloServiceImpl&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig2&lt;span style="color:#719e07">.&lt;/span>setVersion&lt;span style="color:#719e07">(&lt;/span>version2&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// set executor2 for serviceConfig2, max threads is 100
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> NamedThreadFactory threadFactory2 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> NamedThreadFactory&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;HelloService-executor&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ExecutorService executor2 &lt;span style="color:#719e07">=&lt;/span> Executors&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">newFixedThreadPool&lt;/span>&lt;span style="color:#719e07">(&lt;/span>100&lt;span style="color:#719e07">,&lt;/span> threadFactory2&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig2&lt;span style="color:#719e07">.&lt;/span>setExecutor&lt;span style="color:#719e07">(&lt;/span>executor2&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ServiceConfig serviceConfig3 &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig3&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>HelloService&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig3&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> HelloServiceImpl&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> serviceConfig3&lt;span style="color:#719e07">.&lt;/span>setVersion&lt;span style="color:#719e07">(&lt;/span>version3&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Because executor is not set for serviceConfig3, the default executor of serviceConfig3 is built using
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#586e75">// the threadpool parameter of the protocolConfig ( FixedThreadpool , max threads is 200)
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> serviceConfig3&lt;span style="color:#719e07">.&lt;/span>setExecutor&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// It takes effect only if [executor-management-mode=isolation] is configured
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> ApplicationConfig applicationConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;provider-app&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> applicationConfig&lt;span style="color:#719e07">.&lt;/span>setExecutorManagementMode&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;isolation&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> providerBootstrap
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>application&lt;span style="color:#719e07">(&lt;/span>applicationConfig&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>registry&lt;span style="color:#719e07">(&lt;/span>registryConfig&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// export with tri and dubbo protocol
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">.&lt;/span>protocol&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;tri&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> 20001&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>protocol&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> 20002&lt;span style="color:#719e07">))&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>service&lt;span style="color:#719e07">(&lt;/span>serviceConfig1&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>service&lt;span style="color:#719e07">(&lt;/span>serviceConfig2&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">.&lt;/span>service&lt;span style="color:#719e07">(&lt;/span>serviceConfig3&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> providerBootstrap&lt;span style="color:#719e07">.&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="xml">XML&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#2aa198"> http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- NOTE: we need config executor-management-mode=&amp;#34;isolation&amp;#34; --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;demo-provider&amp;#34;&lt;/span> executor-management-mode=&lt;span style="color:#2aa198">&amp;#34;isolation&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/dubbo:application&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:config-center&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:metadata-report&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;registry1&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181?registry-type=service&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;-1&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;tri&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;-1&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- expose three service with dubbo and tri protocol--&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoServiceV1&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.impl.DemoServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;helloServiceV2&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.impl.HelloServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;helloServiceV3&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.impl.HelloServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- customized thread pool --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;executor-demo-service&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.isolation.spring.support.DemoServiceExecutor&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;executor-hello-service&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.isolation.spring.support.HelloServiceExecutor&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- this service use [executor=&amp;#34;executor-demo-service&amp;#34;] as isolated thread pool--&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> executor=&lt;span style="color:#2aa198">&amp;#34;executor-demo-service&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.api.DemoService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;Group1&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> timeout=&lt;span style="color:#2aa198">&amp;#34;3000&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;demoServiceV1&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;registry1&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo,tri&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- this service use [executor=&amp;#34;executor-hello-service&amp;#34;] as isolated thread pool--&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> executor=&lt;span style="color:#2aa198">&amp;#34;executor-hello-service&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;2.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;Group2&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> timeout=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;helloServiceV2&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;registry1&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo,tri&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- not set executor for this service, the default executor built using threadpool parameter of the protocolConfig --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;3.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;Group3&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> timeout=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;helloServiceV3&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;registry1&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo,tri&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="annotation">Annotation&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@Configuration&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@EnableDubbo&lt;/span>&lt;span style="color:#719e07">(&lt;/span>scanBasePackages &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.config.spring.isolation.spring.annotation.provider&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">ProviderConfiguration&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Bean&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> RegistryConfig &lt;span style="color:#268bd2">registryConfig&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> RegistryConfig registryConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> RegistryConfig&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> registryConfig&lt;span style="color:#719e07">.&lt;/span>setAddress&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> registryConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// NOTE: we need config executor-management-mode=&amp;#34;isolation&amp;#34;
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Bean&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> ApplicationConfig &lt;span style="color:#268bd2">applicationConfig&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ApplicationConfig applicationConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ApplicationConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;provider-app&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> applicationConfig&lt;span style="color:#719e07">.&lt;/span>setExecutorManagementMode&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;isolation&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> applicationConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// expose services with dubbo protocol
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Bean&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> ProtocolConfig &lt;span style="color:#268bd2">dubbo&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ProtocolConfig protocolConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> protocolConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// expose services with tri protocol
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Bean&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> ProtocolConfig &lt;span style="color:#268bd2">tri&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ProtocolConfig protocolConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ProtocolConfig&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;tri&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> protocolConfig&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// customized thread pool
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Bean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;executor-demo-service&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Executor &lt;span style="color:#268bd2">demoServiceExecutor&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> DemoServiceExecutor&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// customized thread pool
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">@Bean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;executor-hello-service&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Executor &lt;span style="color:#268bd2">helloServiceExecutor&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HelloServiceExecutor&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// customized thread pool
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">DemoServiceExecutor&lt;/span> &lt;span style="color:#268bd2">extends&lt;/span> ThreadPoolExecutor &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">DemoServiceExecutor&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">super&lt;/span>&lt;span style="color:#719e07">(&lt;/span>10&lt;span style="color:#719e07">,&lt;/span> 10&lt;span style="color:#719e07">,&lt;/span> 60&lt;span style="color:#719e07">,&lt;/span> TimeUnit&lt;span style="color:#719e07">.&lt;/span> SECONDS&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> LinkedBlockingDeque&lt;span style="color:#719e07">&amp;lt;&amp;gt;(),&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> NamedThreadFactory&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;DemoServiceExecutor&amp;#34;&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// customized thread pool
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">HelloServiceExecutor&lt;/span> &lt;span style="color:#268bd2">extends&lt;/span> ThreadPoolExecutor &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">HelloServiceExecutor&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">super&lt;/span>&lt;span style="color:#719e07">(&lt;/span>100&lt;span style="color:#719e07">,&lt;/span> 100&lt;span style="color:#719e07">,&lt;/span> 60&lt;span style="color:#719e07">,&lt;/span> TimeUnit&lt;span style="color:#719e07">.&lt;/span> SECONDS&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> LinkedBlockingDeque&lt;span style="color:#719e07">&amp;lt;&amp;gt;(),&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> NamedThreadFactory&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;HelloServiceExecutor&amp;#34;&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// &amp;#34;executor-hello-service&amp;#34; is beanName
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">@DubboService&lt;/span>&lt;span style="color:#719e07">(&lt;/span>executor &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;executor-demo-service&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> version &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;Group1&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">DemoServiceImplV1&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> DemoService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayName&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;server name&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Box &lt;span style="color:#268bd2">getBox&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// not set executor for this service, the default executor built using threadpool parameter of the protocolConfig
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#268bd2">@DubboService&lt;/span>&lt;span style="color:#719e07">(&lt;/span>version &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;3.0.0&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;Group3&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">HelloServiceImplV2&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> HelloService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> Logger logger &lt;span style="color:#719e07">=&lt;/span> LoggerFactory&lt;span style="color:#719e07">.&lt;/span>getLogger&lt;span style="color:#719e07">(&lt;/span>HelloServiceImplV2&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;server hello&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@DubboService&lt;/span>&lt;span style="color:#719e07">(&lt;/span>executor &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;executor-hello-service&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> version &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;2.0.0&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> group &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#2aa198">&amp;#34;Group2&amp;#34;&lt;/span>&lt;span style="color:#719e07">)&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">HelloServiceImplV3&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> HelloService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> Logger logger &lt;span style="color:#719e07">=&lt;/span> LoggerFactory&lt;span style="color:#719e07">.&lt;/span>getLogger&lt;span style="color:#719e07">(&lt;/span>HelloServiceImplV3&lt;span style="color:#719e07">.&lt;/span>class&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;server hello&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Call link to pass implicit parameters</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/attachment/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/attachment/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Parameters can be implicitly passed between the service consumer and the provider through &lt;code>setAttachment&lt;/code> and &lt;code>getAttachment&lt;/code> on &lt;code>RpcContext&lt;/code>.&lt;/p>
&lt;h4 id="background">background&lt;/h4>
&lt;p>Context information is a very important function of the RPC framework. Using RpcContext can specify different configurations for a single call. For example, in the distributed link tracking scenario, the implementation principle is to maintain a traceId in the context of the entire link. The Consumer and Provider connect an RPC call by passing the traceId. After reporting the logs respectively, they can be connected in series in the tracking system and display the complete call. process. In this way, it is easier to find abnormalities and locate problems.
RpcContext in Dubbo is a ThreadLocal temporary state recorder. When RPC requests are received or RPC requests are initiated, the state of RpcContext will change. For example: **A tunes B, B tunes C, then on machine B, before B tunes C, RpcContext records the information of A and B, after B tunes C, RpcContext records the information of B and C. **&lt;/p>
&lt;p>In Dubbo 3, RpcContext is split into four major modules (ServerContext, ClientAttachment, ServerAttachment and ServiceContext).&lt;/p>
&lt;p>They bear different accusations respectively:&lt;/p>
&lt;ul>
&lt;li>ServiceContext: Used internally by Dubbo to pass parameter information on the call link, such as invoker objects, etc.&lt;/li>
&lt;li>ClientAttachment: Used on the client side, the parameters written in ClientAttachment will be passed to the server side&lt;/li>
&lt;li>ServerAttachment: Used on the Server side, the parameters read from ServerAttachment are passed from the Client&lt;/li>
&lt;li>ServerContext: It is used on both the client side and the server side, and is used to pass back from the server side to the client side. The parameters written by the server side to the ServerContext can be obtained from the ServerContext on the client side after the call ends&lt;/li>
&lt;/ul>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/v3/concepts/rpccontext.png" alt="/imgs/v3/concepts/rpccontext.png">&lt;/p>
&lt;p>As shown in the figure above, when the consumer initiates an invocation, it can directly initiate a call to the remote service through Method Invoke, and at the same time, the data written by the consumer to RpcClientAttachment will be written into Invocation together with the parameter information of Invoke.
The Invocation on the consumer side is serialized and sent to the server through network transmission. The server parses the Invocation to generate the parameters of Method Invoke and RpcServerAttachment, and then initiates the real call.
After the processing on the server end, the Method Response result together with the RpcServiceContext will generate a Result object.
The Result object on the server is serialized and sent back to the consumer through network transmission. The consumer parses the Result to generate a Method Response result and RpcServiceContext, and returns the actual call result and context to the consumer.&lt;/p>
&lt;blockquote>
&lt;p>path, group, version, dubbo, token, timeout several keys are reserved fields, please use other values.&lt;/p>
&lt;/blockquote>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>How to transparently transmit traceId to the service provider when the internal system calls through Dubbo.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;blockquote>
&lt;p>The KV pair set by &lt;code>setAttachment&lt;/code> will be cleared after the following remote call is completed, that is, multiple remote calls need to be set multiple times.&lt;/p>
&lt;/blockquote>
&lt;h3 id="set-implicit-parameters-on-the-service-consumer-side">Set implicit parameters on the service consumer side&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>RpcContext&lt;span style="color:#719e07">.&lt;/span>getClientAttachment&lt;span style="color:#719e07">().&lt;/span>setAttachment&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;index&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span> &lt;span style="color:#586e75">// Implicit parameter passing, subsequent remote calls will implicitly send these parameters to the server, similar to cookies, used for framework integration, not recommended business use
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>xxxService&lt;span style="color:#719e07">.&lt;/span>xxx&lt;span style="color:#719e07">();&lt;/span> &lt;span style="color:#586e75">// remote call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">//...
&lt;/span>&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="obtain-implicit-parameters-on-the-service-provider-side">Obtain implicit parameters on the service provider side&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">XxxServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> XxxService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">xxx&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Obtain the parameters implicitly passed in by the client for framework integration, not recommended for general business use
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> String index &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServerAttachment&lt;span style="color:#719e07">().&lt;/span>getAttachment&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;index&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="write-return-parameters-in-the-service-provider">Write return parameters in the service provider&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">XxxServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> XxxService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">xxx&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String index &lt;span style="color:#719e07">=&lt;/span> xxx&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServerContext&lt;span style="color:#719e07">().&lt;/span>setAttachment&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;result&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> index&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="obtain-the-return-parameters-on-the-consumer-side">Obtain the return parameters on the consumer side&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>xxxService&lt;span style="color:#719e07">.&lt;/span>xxx&lt;span style="color:#719e07">();&lt;/span> &lt;span style="color:#586e75">// remote call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>String result &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServerContext&lt;span style="color:#719e07">().&lt;/span>getAttachment&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;result&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">//...
&lt;/span>&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="parameter-transparent-transmission-problem">Parameter transparent transmission problem&lt;/h2>
&lt;p>In Dubbo 2.7, after the parameters set on the A side are called, if B continues to call C, the parameters originally set in A will also be brought to the C side, causing the problem of parameter pollution.
Dubbo 3 has refactored RpcContext to support optional parameter transparent transmission, and parameter transparent transmission is enabled by default.&lt;/p>
&lt;p>The following SPI is provided in Dubbo 3. There is no implementation by default. Users can define their own implementation. The result of &lt;code>select&lt;/code> (you can get all the current parameters from RpcClientAttachment) will be passed to the next hop as a key-value pair that needs to be transparently transmitted. If Returning null means that parameters are not transparently passed.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">@SPI&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">PenetrateAttachmentSelector&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">/**
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * Select some attachments to pass to next hop.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * These attachments can fetch from {@link RpcContext#getServerAttachment()} or user defined.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> *
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> * @return attachment pass to next hop
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75"> */&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">select&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Direct Connection Provider</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/explicit-target/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/explicit-target/</guid><description>
&lt;div class="pageinfo pageinfo-primary">
&lt;p>This document is no longer maintained. You are currently viewing a snapshot version. If you want to view the latest version of the documentation, see &lt;a href="https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/specify-ip/">Latest Version&lt;/a>.&lt;/p>
&lt;/div>
&lt;p>In the development and testing environment, it is often necessary to bypass the registration center and only test the specified service provider. At this time, point-to-point direct connection may be required. The point-to-point direct connection method will use the service interface as the unit and ignore the provider list of the registration center. A The point-to-point interface configuration does not affect the B interface to obtain the list from the registration center.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/dubbo-directly.jpg" alt="/user-guide/images/dubbo-directly.jpg">&lt;/p>
&lt;h2 id="configuration-via-xml">Configuration via XML&lt;/h2>
&lt;p>If the online demand needs point-to-point, you can configure the url to point to the provider in &lt;code>&amp;lt;dubbo:reference&amp;gt;&lt;/code>, which will bypass the registration center. Multiple addresses are separated by semicolons, and the configuration is as follows:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;xxxService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.xxx.XxxService&amp;#34;&lt;/span> url=&lt;span style="color:#2aa198">&amp;#34;dubbo://localhost:20890&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>
&lt;div class="alert alert-primary" role="alert">
&lt;h4 class="alert-heading">Prompt&lt;/h4>
&lt;code>1.0.6&lt;/code> and above version support
&lt;/div>
&lt;h2 id="specified-by--d-parameter">Specified by -D parameter&lt;/h2>
&lt;p>Add the -D parameter mapping service address to the JVM startup parameters, such as:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-sh" data-lang="sh">&lt;span style="display:flex;">&lt;span>java -Dcom.alibaba.xxx.XxxService&lt;span style="color:#719e07">=&lt;/span>dubbo://localhost:20890
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>
&lt;div class="alert alert-primary" role="alert">
&lt;h4 class="alert-heading">Prompt&lt;/h4>
The key is the service name, and the value is the service provider url. This configuration has the highest priority and is supported by &lt;code>1.0.15&lt;/code> and above versions
&lt;/div>
&lt;h2 id="by-file-mapping">By file mapping&lt;/h2>
&lt;p>If there are many services, you can also use file mapping, use &lt;code>-Ddubbo.resolve.file&lt;/code> to specify the mapping file path, this configuration has a higher priority than the configuration [^3] in &lt;code>&amp;lt;dubbo:reference&amp;gt;&lt;/code>, such as:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-sh" data-lang="sh">&lt;span style="display:flex;">&lt;span>java -Ddubbo.resolve.file&lt;span style="color:#719e07">=&lt;/span>xxx.properties
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Then add the configuration to the mapping file &lt;code>xxx.properties&lt;/code>, where the key is the service name and the value is the service provider URL:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-properties" data-lang="properties">&lt;span style="display:flex;">&lt;span>com.alibaba.xxx.XxxService&lt;span style="color:#719e07">=&lt;/span>&lt;span style="color:#2aa198">dubbo://localhost:20890&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>
&lt;div class="alert alert-primary" role="alert">
&lt;h4 class="alert-heading">Prompt&lt;/h4>
&lt;code>1.0.15&lt;/code> and above versions support, &lt;code>2.0&lt;/code> and above versions automatically load the ${user.home}/dubbo-resolve.properties file, no configuration required
&lt;/div>
&lt;div class="alert alert-warning" role="alert">
&lt;h4 class="alert-heading">Attention&lt;/h4>
In order to avoid complicating the online environment, do not use this feature online, it should only be used during the testing phase.
&lt;/div></description></item><item><title>Docs3-V2: Dynamic IP call</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/specify-ip/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/specify-ip/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Use the extension of Dubbo to realize the specified IP call.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When initiating a request, you need to specify the server for this call, such as message callback, traffic isolation, etc.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="plugin-dependencies">Plugin dependencies&lt;/h3>
&lt;p>Adapt to Dubbo 3 version&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.apache.dubbo.extensions&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>dubbo-cluster-specify-address-dubbo3&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>1.0.0&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Adapt to Dubbo 2 version&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;groupId&amp;gt;&lt;/span>org.apache.dubbo.extensions&lt;span style="color:#268bd2">&amp;lt;/groupId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;artifactId&amp;gt;&lt;/span>dubbo-cluster-specify-address-dubbo2&lt;span style="color:#268bd2">&amp;lt;/artifactId&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;version&amp;gt;&lt;/span>1.0.0&lt;span style="color:#268bd2">&amp;lt;/version&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dependency&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="call-example">call example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> referenceConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// ...init
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>DemoService demoService &lt;span style="color:#719e07">=&lt;/span> referenceConfig&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// for invoke
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// 1. find 10.10.10.10:20880 exist
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// 2. if not exist, create a invoker to 10.10.10.10:20880 if `needToCreate` is true (only support in Dubbo 3.x&amp;#39;s implementation)
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>UserSpecifiedAddressUtil&lt;span style="color:#719e07">.&lt;/span>setAddress&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> Address&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;10.10.10.10&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> 20880&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>demoService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// for invoke
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// 1. find 10.10.10.10:any exist
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// 2. if not exist, create a invoker to 10.10.10.10:20880 if `needToCreate` is true (only support in Dubbo 3.x&amp;#39;s implementation)
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>UserSpecifiedAddressUtil&lt;span style="color:#719e07">.&lt;/span>setAddress&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> Address&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;10.10.10.10&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> 0&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>demoService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="parameter-description">Parameter Description&lt;/h3>
&lt;p>Parameters specifying an IP call wrap around an &lt;code>Address&lt;/code> object. The parameter type reference is as follows:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org.apache.dubbo.rpc.cluster.specifyaddress&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">Address&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> Serializable &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// ip - priority: 3
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> String ip&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// ip+port - priority: 2
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#dc322f">int&lt;/span> port&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// address - priority: 1
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">private&lt;/span> URL urlAddress&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#dc322f">boolean&lt;/span> needToCreate &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#cb4b16">false&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// ignore setter and getter
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;ol>
&lt;li>&lt;code>urlAddress&lt;/code> is the highest priority, if the URL address of the target is specified, it will be used first. (no longer matches follow-up)&lt;/li>
&lt;li>ip + port (non-0 port) is the second priority, and will be matched from the addresses that have been pushed by the registration center. (no longer matches follow-up)&lt;/li>
&lt;li>IP is the third priority, and it will be matched from the addresses that have been pushed by the registration center.&lt;/li>
&lt;/ol>
&lt;p>In particular, if &lt;code>needToCreate&lt;/code> is specified as &lt;code>true&lt;/code>, an invoker will be automatically built according to the parameters passed in. For addresses specified by specifying ip ( + port ),
It will automatically use the parameter of the first address in the registry to create the template; if there is no address, it will be automatically created based on the Dubbo protocol.
To customize the logic of creating invoker, please implement &lt;code>org.apache.dubbo.rpc.cluster.specifyaddress.UserSpecifiedServiceAddressBuilder&lt;/code> SPI interface. (This function is only supported by &lt;strong>Dubbo 3 implementation&lt;/strong>)&lt;/p>
&lt;p>Pass the &lt;code>UserSpecifiedAddressUtil&lt;/code> tool class to the Dubbo framework before constructing the &lt;code>Address&lt;/code> parameter for each request.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> org.apache.dubbo.rpc.cluster.specifyaddress&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">UserSpecifiedAddressUtil&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">static&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">setAddress&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Address address&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span> &lt;span style="color:#719e07">...&lt;/span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;blockquote>
&lt;p>&lt;strong>Must be set every time, and the call must be initiated immediately after setting&lt;/strong>, if there is an interceptor error (remove this value in the Dubbo framework is performed during the address selection process), it is recommended to set null to avoid ThreadLocal memory leaks that will affect the follow-up transfer.&lt;/p>
&lt;/blockquote></description></item><item><title>Docs3-V2: Consistent Hash Site Selection</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/consistent-hash/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/consistent-hash/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>[Analysis of Dubbo Consistent Hash Load Balancing Implementation](/zh-cn/blog/2019/05/01/dubbo-%E4%B8%80%E8%87%B4%E6%80%A7hash%E8%B4%9F%E8 %BD%BD%E5%9D%87%E8%A1%A1%E5%AE%9E%E7%8E%B0%E5%89%96%E6%9E%90/)&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When there are multiple servers, the server is selected according to the consistent hashing of the request parameters.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>There are many ways to configure consistent hashing, the most common are:&lt;/p>
&lt;h3 id="annotation-configuration">Annotation configuration&lt;/h3>
&lt;blockquote>
&lt;p>@DubboReference(loadbalance = &amp;ldquo;consistenthash&amp;rdquo;)&lt;/p>
&lt;/blockquote>
&lt;h3 id="api-configuration">API configuration&lt;/h3>
&lt;blockquote>
&lt;p>referenceConfig.setLoadBalance(&amp;ldquo;consistenthash&amp;rdquo;);&lt;/p>
&lt;/blockquote>
&lt;h3 id="properties-configuration">Properties configuration&lt;/h3>
&lt;blockquote>
&lt;p>dubbo.reference.loadbalance=consistenthash&lt;/p>
&lt;/blockquote>
&lt;h3 id="xml-configuration">XML configuration&lt;/h3>
&lt;blockquote>
&lt;p>&amp;lt;dubbo:reference loadbalance=&amp;ldquo;consistenthash&amp;rdquo; /&amp;gt;&lt;/p>
&lt;/blockquote>
&lt;p>By default, the first parameter is used as the hash key. If you need to switch parameters, you can specify the &lt;code>hash.arguments&lt;/code> property&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;&lt;/span> referenceConfig &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ReferenceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>DemoService&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// ...init
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> String&lt;span style="color:#719e07">&amp;gt;&lt;/span> parameters &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> String&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>parameters&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;hash. arguments&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>parameters&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello. hash. arguments&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;0,1&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>referenceConfig&lt;span style="color:#719e07">.&lt;/span>setParameters&lt;span style="color:#719e07">(&lt;/span>parameters&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>referenceConfig&lt;span style="color:#719e07">.&lt;/span>setLoadBalance&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;consistenthash&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>referenceConfig&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: RPC call context</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/context/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/context/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The context stores the environment information needed in the current calling process. All configuration information will be converted to URL parameters, see the &lt;strong>corresponding URL parameters&lt;/strong> column in &lt;a href="../../../reference-manual/config/properties/">schema configuration reference manual&lt;/a>.&lt;/p>
&lt;p>RpcContext is a temporary state recorder for ThreadLocal. When RPC requests are received or RPC requests are initiated, the state of RpcContext will change. For example: A tunes B, B then tunes C, then on machine B, before B tunes C, RpcContext records the information of A&amp;rsquo;s tune to B, after B tunes C, RpcContext records the information of B&amp;rsquo;s tune to C.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Global link tracking and hiding parameters.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="service-consumer">Service consumer&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// remote call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>xxxService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">xxx&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Whether this end is a consumer end, here will return true
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#dc322f">boolean&lt;/span> isConsumerSide &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>isConsumerSide&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Get the provider IP address of the last call
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>String serverIP &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>getRemoteHost&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Get the current service configuration information, all configuration information will be converted into URL parameters
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>String application &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>getUrl&lt;span style="color:#719e07">().&lt;/span>getParameter&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;application&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Note: Every time an RPC call is initiated, the context state will change
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>yyyService&lt;span style="color:#719e07">.&lt;/span>yyy&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-provider">Service Provider&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">XxxServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> XxxService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">xxx&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Whether this end is the provider end, here will return true
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#dc322f">boolean&lt;/span> isProviderSide &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>isProviderSide&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Get the IP address of the caller
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> String clientIP &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>getRemoteHost&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Get the current service configuration information, all configuration information will be converted into URL parameters
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> String application &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>getUrl&lt;span style="color:#719e07">().&lt;/span>getParameter&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;application&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// Note: Every time an RPC call is initiated, the context state will change
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> yyyService&lt;span style="color:#719e07">.&lt;/span>yyy&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// At this point, the local end becomes the consumer end, and false will be returned here
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#dc322f">boolean&lt;/span> isProviderSide &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>isProviderSide&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Subscription Only</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/subscribe-only/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/subscribe-only/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>In order to facilitate development and testing, a registration center that is available for all services is often shared offline. At this time, if a service provider under development registers, it may affect the normal operation of consumers.&lt;/p>
&lt;p>The service provider developer can only subscribe to the service (the developed service may depend on other services), without registering the service under development, and test the service under development through direct connection.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/subscribe-only.jpg" alt="/user-guide/images/subscribe-only.jpg">&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="disable-registration-configuration">Disable registration configuration&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.153.10:9090&amp;#34;&lt;/span> register=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;strong>or&lt;/strong>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.153.10:9090?register=false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Call trigger event notification</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/events-notify/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/events-notify/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Before calling, after calling, and when an exception occurs, three events &lt;code>oninvoke&lt;/code>, &lt;code>onreturn&lt;/code>, and &lt;code>onthrow&lt;/code> will be triggered. You can configure which method of which class to notify when an event occurs.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-notify">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-notify&lt;/a>&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Before calling the service method, we can record the start time, and after the call ends, we can count the entire call cost. When an exception occurs, we can warn or print error logs, or record request logs and response logs before and after calling the service.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="service-provider-and-consumer-share-service-interface">Service provider and consumer share service interface&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">IDemoService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Person &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#dc322f">int&lt;/span> id&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-provider-implementation">Service provider implementation&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">NormalDemoService&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> IDemoService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Person &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#dc322f">int&lt;/span> id&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Person&lt;span style="color:#719e07">(&lt;/span>id&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#2aa198">&amp;#34;charles`son&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> 4&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-provider-configuration">Service provider configuration&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;rpc-callback-demo&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;zookeeper://127.0.0.1:2181&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.callback.implicit.NormalDemoService&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.callback.implicit.IDemoService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;cn&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer-callback-interface">Service consumer Callback interface&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">Notify&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">onreturn&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Person msg&lt;span style="color:#719e07">,&lt;/span> Integer id&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">onthrow&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Throwable ex&lt;span style="color:#719e07">,&lt;/span> Integer id&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer-callback-implementation">Service consumer Callback implementation&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">NotifyImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> Notify &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>Integer&lt;span style="color:#719e07">,&lt;/span> Person&lt;span style="color:#719e07">&amp;gt;&lt;/span> ret &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>Integer&lt;span style="color:#719e07">,&lt;/span> Person&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>Integer&lt;span style="color:#719e07">,&lt;/span> Throwable&lt;span style="color:#719e07">&amp;gt;&lt;/span> errors &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> HashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>Integer&lt;span style="color:#719e07">,&lt;/span> Throwable&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">onreturn&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Person msg&lt;span style="color:#719e07">,&lt;/span> Integer id&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;onreturn:&amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> msg&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> ret&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>id&lt;span style="color:#719e07">,&lt;/span> msg&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">onthrow&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Throwable ex&lt;span style="color:#719e07">,&lt;/span> Integer id&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> errors&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>id&lt;span style="color:#719e07">,&lt;/span> ex&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer-callback-configuration">Service consumer Callback configuration&lt;/h3>
&lt;p>There are the following combinations of the two:&lt;/p>
&lt;ul>
&lt;li>Asynchronous callback mode: &lt;code>async=true onreturn=&amp;quot;xxx&amp;quot;&lt;/code>&lt;/li>
&lt;li>Synchronous callback mode: &lt;code>async=false onreturn=&amp;quot;xxx&amp;quot;&lt;/code>&lt;/li>
&lt;li>Asynchronous without callback: &lt;code>async=true&lt;/code>&lt;/li>
&lt;li>Synchronous without callback: &lt;code>async=false&lt;/code>&lt;/li>
&lt;/ul>
&lt;p>&lt;code>callback&lt;/code> and &lt;code>async&lt;/code> function are decomposed orthogonally, &lt;code>async=true&lt;/code> indicates whether the result is returned immediately, &lt;code>async=false&lt;/code> is the default, &lt;code>onreturn&lt;/code> indicates whether a callback is required.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoCallback&amp;#34;&lt;/span> class = &lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.callback.implicit.NotifyImpl&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.callback.implicit.IDemoService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> group=&lt;span style="color:#2aa198">&amp;#34;cn&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;get&amp;#34;&lt;/span> async=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> onreturn = &lt;span style="color:#2aa198">&amp;#34;demoCallback.onreturn&amp;#34;&lt;/span> onthrow=&lt;span style="color:#2aa198">&amp;#34;demoCallback.onthrow&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="test-code">Test code&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>IDemoService demoService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>IDemoService&lt;span style="color:#719e07">)&lt;/span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>NotifyImpl notify &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>NotifyImpl&lt;span style="color:#719e07">)&lt;/span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;demoCallback&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#dc322f">int&lt;/span> requestId &lt;span style="color:#719e07">=&lt;/span> 2&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>Person ret &lt;span style="color:#719e07">=&lt;/span> demoService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">get&lt;/span>&lt;span style="color:#719e07">(&lt;/span>requestId&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>Assert&lt;span style="color:#719e07">.&lt;/span>assertEquals&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">,&lt;/span> ret&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">//for Test: It is only used to illustrate that the callback is called normally, and the specific implementation of the business is determined by itself.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>&lt;span style="color:#719e07">for&lt;/span> &lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#dc322f">int&lt;/span> i &lt;span style="color:#719e07">=&lt;/span> 0&lt;span style="color:#719e07">;&lt;/span> i &lt;span style="color:#719e07">&amp;lt;&lt;/span> 10&lt;span style="color:#719e07">;&lt;/span> i&lt;span style="color:#719e07">++)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">if&lt;/span> &lt;span style="color:#719e07">(!&lt;/span>notify&lt;span style="color:#719e07">.&lt;/span>ret&lt;span style="color:#719e07">.&lt;/span>containsKey&lt;span style="color:#719e07">(&lt;/span>requestId&lt;span style="color:#719e07">))&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>200&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">else&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">break&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>Assert&lt;span style="color:#719e07">.&lt;/span>assertEquals&lt;span style="color:#719e07">(&lt;/span>requestId&lt;span style="color:#719e07">,&lt;/span> notify&lt;span style="color:#719e07">.&lt;/span>ret&lt;span style="color:#719e07">.&lt;/span>get&lt;span style="color:#719e07">(&lt;/span>requestId&lt;span style="color:#719e07">).&lt;/span>getId&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Multi-protocol</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-protocols/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-protocols/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Dubbo allows multi-protocol configuration, supports different protocols on different services or supports multiple protocols on the same service at the same time.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="different-protocols-for-different-services">Different protocols for different services&lt;/h3>
&lt;p>Different services apply different protocols for transmission in terms of performance. For example, short connection protocols are used for large data, and long connection protocols are used for small data and large concurrency.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;registry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> username=&lt;span style="color:#2aa198">&amp;#34;admin&amp;#34;&lt;/span> password=&lt;span style="color:#2aa198">&amp;#34;hello1234&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-protocol configuration --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;20880&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;rmi&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;1099&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Use dubbo protocol to expose services --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Use rmi protocol to expose services --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.DemoService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;rmi&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="multi-protocol-exposed-services">Multi-protocol exposed services&lt;/h3>
&lt;p>Needed to interoperate with http clients&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;registry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> username=&lt;span style="color:#2aa198">&amp;#34;admin&amp;#34;&lt;/span> password=&lt;span style="color:#2aa198">&amp;#34;hello1234&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-protocol configuration --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;dubbo&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;20880&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;hessian&amp;#34;&lt;/span> port=&lt;span style="color:#2aa198">&amp;#34;8080&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Exposing services using multiple protocols --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;dubbo,hessian&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: The server makes a callback to the client</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/callback-parameter/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/callback-parameter/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The parameter callback method is the same as calling a local callback or listener, you only need to declare which parameter is the callback type in the Spring configuration file. Dubbo will generate a reverse proxy based on the persistent connection, so that the client logic can be invoked from the server. You can refer to &lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-callback">sample code in the dubbo project&lt;/a>.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>The callback function notifies the client of the execution result, or sends a notification. When the method execution time is relatively long, it is similar to an asynchronous call, and the client approval result is called back in the approval workflow.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="service-interface-example">Service interface example&lt;/h3>
&lt;p>CallbackService.java&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com. callback&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">CallbackService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">addListener&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String key&lt;span style="color:#719e07">,&lt;/span> CallbackListener listener&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>CallbackListener.java&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com. callback&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">CallbackListener&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">changed&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String msg&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-provider-interface-implementation-example">Service provider interface implementation example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com.callback.impl&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.text.SimpleDateFormat&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.util.Date&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.util.Map&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> java.util.concurrent.ConcurrentHashMap&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> com.callback.CallbackListener&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">import&lt;/span> com.callback.CallbackService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">CallbackServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> CallbackService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> Map&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> CallbackListener&lt;span style="color:#719e07">&amp;gt;&lt;/span> listeners &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ConcurrentHashMap&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> CallbackListener&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">CallbackServiceImpl&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread t &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> Runnable&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">run&lt;/span>&lt;span style="color:#719e07">()&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">while&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">for&lt;/span>&lt;span style="color:#719e07">(&lt;/span>Map&lt;span style="color:#719e07">.&lt;/span>Entry&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">,&lt;/span> CallbackListener&lt;span style="color:#719e07">&amp;gt;&lt;/span> entry &lt;span style="color:#719e07">:&lt;/span> listeners&lt;span style="color:#719e07">.&lt;/span>entrySet&lt;span style="color:#719e07">()){&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> entry&lt;span style="color:#719e07">.&lt;/span>getValue&lt;span style="color:#719e07">().&lt;/span>changed&lt;span style="color:#719e07">(&lt;/span>getChanged&lt;span style="color:#719e07">(&lt;/span>entry&lt;span style="color:#719e07">.&lt;/span>getKey&lt;span style="color:#719e07">()));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>Throwable t&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> listeners&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">remove&lt;/span>&lt;span style="color:#719e07">(&lt;/span>entry&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getKey&lt;/span>&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span>sleep&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span> &lt;span style="color:#586e75">// Timely trigger change notification
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>Throwable t&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span> &lt;span style="color:#586e75">// defensive fault tolerance
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> t&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">printStackTrace&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> t&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">setDaemon&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> t&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">start&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">addListener&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String key&lt;span style="color:#719e07">,&lt;/span> CallbackListener listener&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> listeners&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">put&lt;/span>&lt;span style="color:#719e07">(&lt;/span>key&lt;span style="color:#719e07">,&lt;/span> listener&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> listener&lt;span style="color:#719e07">.&lt;/span>changed&lt;span style="color:#719e07">(&lt;/span>getChanged&lt;span style="color:#719e07">(&lt;/span>key&lt;span style="color:#719e07">));&lt;/span> &lt;span style="color:#586e75">// send change notification
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> String &lt;span style="color:#268bd2">getChanged&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String key&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;Changed: &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#719e07">new&lt;/span> SimpleDateFormat&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;yyyy-MM-dd HH:mm:ss&amp;#34;&lt;/span>&lt;span style="color:#719e07">).&lt;/span>format&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#719e07">new&lt;/span> Date&lt;span style="color:#719e07">());&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-provider-configuration-example">Service provider configuration example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;callbackService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;com.callback.impl.CallbackServiceImpl&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.callback.CallbackService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;callbackService&amp;#34;&lt;/span> connections=&lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span> callbacks=&lt;span style="color:#2aa198">&amp;#34;1000&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:method&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;addListener&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:argument&lt;/span> index=&lt;span style="color:#2aa198">&amp;#34;1&amp;#34;&lt;/span> callback=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!--You can also specify the type --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!--&amp;lt;dubbo:argument type=&amp;#34;com.demo.CallbackListener&amp;#34; callback=&amp;#34;true&amp;#34; /&amp;gt;--&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;/dubbo:method&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:service&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer-configuration-example">Service consumer configuration example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;callbackService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.callback.CallbackService&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="service-consumer-call-example">Service consumer call example&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>ClassPathXmlApplicationContext context &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ClassPathXmlApplicationContext&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;classpath:consumer.xml&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">start&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>CallbackService callbackService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>CallbackService&lt;span style="color:#719e07">)&lt;/span> context&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;callbackService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>callbackService&lt;span style="color:#719e07">.&lt;/span>addListener&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;foo.bar&amp;#34;&lt;/span>&lt;span style="color:#719e07">,&lt;/span> &lt;span style="color:#719e07">new&lt;/span> CallbackListener&lt;span style="color:#719e07">(){&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#dc322f">void&lt;/span> &lt;span style="color:#268bd2">changed&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String msg&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;callback1:&amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> msg&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Local Masquerade</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-mock/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-mock/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>There is a mechanism in Dubbo3 to achieve lightweight service degradation, which is local masquerade&lt;sup id="fnref:1">&lt;a href="#fn:1" class="footnote-ref" role="doc-noteref">1&lt;/a>&lt;/sup>.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Local masquerading is often used for service degradation. For example, for a verification service, when all the service providers hang up, if the service consumer initiates a remote call at this time, the call will fail and an &lt;code>RpcException&lt;/code> will be thrown.&lt;/p>
&lt;p>In order to avoid such a situation where an exception is thrown directly, the client can use local masquerade to provide Mock data and return authorization failure.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="enable-mock-configuration">Enable mock configuration&lt;/h3>
&lt;p>Configured in the following way in the Spring XML configuration file:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>or&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarServiceMock&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Provide Mock implementation in the project &lt;sup id="fnref:2">&lt;a href="#fn:2" class="footnote-ref" role="doc-noteref">2&lt;/a>&lt;/sup>:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com.foo&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">BarServiceMock&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> BarService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// You can fake fault-tolerant data, this method is only executed when RpcException occurs
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;fault tolerance data&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="use-the-return-keyword-to-mock-the-return-value">Use the return keyword to mock the return value&lt;/h3>
&lt;p>Use &lt;code>return&lt;/code> to return an object represented by a string as the return value of the Mock. Legal strings can be:&lt;/p>
&lt;ul>
&lt;li>&lt;em>empty&lt;/em>: stands for empty, returns the default value of the basic type, the empty value of the collection class, and the empty object of the custom entity class &lt;sup id="fnref:3">&lt;a href="#fn:3" class="footnote-ref" role="doc-noteref">3&lt;/a>&lt;/sup>&lt;/li>
&lt;li>&lt;em>null&lt;/em>: return &lt;code>null&lt;/code>&lt;/li>
&lt;li>&lt;em>true&lt;/em>: returns &lt;code>true&lt;/code>&lt;/li>
&lt;li>&lt;em>false&lt;/em>: return &lt;code>false&lt;/code>&lt;/li>
&lt;li>&lt;em>JSON string&lt;/em>: returns the object obtained after deserializing the JSON string&lt;/li>
&lt;/ul>
&lt;p>For example, if the consumer of the service often needs try-catch to catch exceptions, such as:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">DemoService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Offer &lt;span style="color:#268bd2">findOffer&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String offerId&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Offer offer &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> offer &lt;span style="color:#719e07">=&lt;/span> offerService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">findOffer&lt;/span>&lt;span style="color:#719e07">(&lt;/span>offerId&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>RpcException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> logger&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">error&lt;/span>&lt;span style="color:#719e07">(&lt;/span>e&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> offer&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Then consider changing to a Mock implementation, and &lt;code>return null&lt;/code> in the Mock implementation. If you just want to simply ignore exceptions, it is available in &lt;code>2.0.11&lt;/code> and above:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;return null&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="use-the-throw-keyword-mock-to-throw-an-exception">Use the throw keyword Mock to throw an exception&lt;/h3>
&lt;p>Use &lt;code>throw&lt;/code> to return an Exception object as the return value of the Mock.&lt;/p>
&lt;p>A default RPCException is thrown when the call fails:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;throw&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>When an error occurs in the call, throw the specified Exception &lt;sup id="fnref:4">&lt;a href="#fn:4" class="footnote-ref" role="doc-noteref">4&lt;/a>&lt;/sup>:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;throw com.foo.MockException&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="use-the-force-and-fail-keywords-to-configure-the-behavior-of-the-mock">Use the force and fail keywords to configure the behavior of the Mock&lt;/h3>
&lt;p>&lt;code>force:&lt;/code> means to force the use of Mock behavior, in which case no remote calls will be made.&lt;/p>
&lt;p>&lt;code>fail:&lt;/code> Consistent with the default behavior, the mock behavior is only used when an error occurs in the remote call. That is to say, it is actually possible not to use the &lt;code>fail&lt;/code> keyword when configuring, but to use &lt;code>throw&lt;/code> or &lt;code>return&lt;/code> directly.&lt;/p>
&lt;p>Both &lt;code>force:&lt;/code> and &lt;code>fail:&lt;/code> are supported in combination with &lt;code>throw&lt;/code> or &lt;code>return&lt;/code>.&lt;/p>
&lt;p>Force a specified value to be returned:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;force:return fake&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Force the specified exception to be thrown:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;force:throw com.foo.MockException&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>The specified value is returned when the call fails:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;fail:return fake&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&amp;lt;!-- Equivalent to the following writing --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;return fake&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>An exception is thrown when the call fails&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;fail:throw com.foo.MockException&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&amp;lt;!-- Equivalent to the following writing --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> mock=&lt;span style="color:#2aa198">&amp;#34;throw com.foo.MockException&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="configure-mock-at-method-level">Configure Mock at method level&lt;/h3>
&lt;p>Mock can be specified at the method level, assuming there are several methods on &lt;code>com.foo.BarService&lt;/code>, we can specify Mock behavior for the &lt;code>sayHello()&lt;/code> method separately.&lt;/p>
&lt;p>The specific configuration is as follows. In this example, whenever &lt;code>sayHello()&lt;/code> is called, it is forced to return &amp;ldquo;fake&amp;rdquo;:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> check=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:parameter&lt;/span> key=&lt;span style="color:#2aa198">&amp;#34;sayHello.mock&amp;#34;&lt;/span> value=&lt;span style="color:#2aa198">&amp;#34;force:return fake&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/dubbo:reference&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="precautions">Precautions&lt;/h2>
&lt;div class="footnotes" role="doc-endnotes">
&lt;hr>
&lt;ol>
&lt;li id="fn:1">
&lt;p>Mock is a subset of Stub, which is convenient for service providers to implement fault-tolerant logic on the client side. Because it is often necessary to perform fault-tolerant when RpcException (such as network failure, timeout, etc.) occurs, and when business exceptions (such as login Wrong username and password) does not require fault tolerance. If you use Stub, you may need to catch and rely on the RpcException class, but you can use Mock without relying on RpcException, because its agreement is to execute only when RpcException occurs.&amp;#160;&lt;a href="#fnref:1" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;li id="fn:2">
&lt;p>Next to the interface, put a Mock implementation that implements the BarService interface and has a no-argument constructor. At the same time, if the Mock class is not explicitly specified in the configuration file, then it is necessary to ensure that the fully qualified class name of the Mock class is in the form of &lt;code>original fully qualified class name+Mock&lt;/code>, such as &lt;code>com.foo.BarServiceMock&lt;/code>, otherwise it will be Mock will fail.&amp;#160;&lt;a href="#fnref:2" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;li id="fn:3">
&lt;p>If the return value is an entity class, then it will return an empty object with default values instead of &lt;code>null&lt;/code>.&amp;#160;&lt;a href="#fnref:3" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;li id="fn:4">
&lt;p>Custom exceptions must have a constructor with &lt;code>String&lt;/code> as the input parameter, which will be used to receive exception information.&amp;#160;&lt;a href="#fnref:4" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;/ol>
&lt;/div></description></item><item><title>Docs3-V2: Multiple Registries</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-registry/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/multi-registry/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>Dubbo supports the simultaneous registration of the same service to multiple registries, or the registration of different services to different registries, or even references to services with the same name registered on different registries at the same time. In addition, the registry is &lt;sup id="fnref:1">&lt;a href="#fn:1" class="footnote-ref" role="doc-noteref">1&lt;/a>&lt;/sup> that supports custom extensions.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="multi-registry-registration">Multi-registry registration&lt;/h3>
&lt;p>For example: Some services of the Chinese website are too late to be deployed in Qingdao, and are only deployed in Hangzhou, while other applications in Qingdao need to reference this service, so the service can be registered to two registration centers at the same time.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-registry configuration --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;hangzhouRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;qingdaoRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.151:9010&amp;#34;&lt;/span> default=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Register with multiple registries --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;hangzhouRegistry,qingdaoRegistry&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="different-services-use-different-registries">Different services use different registries&lt;/h3>
&lt;p>For example: some CRM services are specially designed for international websites, and some services are specially designed for Chinese websites.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-registry configuration --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;chinaRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;intlRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.154.177:9010&amp;#34;&lt;/span> default=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Register with the Chinese Station Registration Center --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;chinaRegistry&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Register with the International Station Registration Center --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.DemoService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;demoService&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;intlRegistry&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="multiple-registry-references">Multiple Registry References&lt;/h3>
&lt;p>For example: CRM needs to call the PC2 service of the Chinese station and the international station at the same time. PC2 is deployed in both the Chinese station and the international station. The interface and version number are the same, but the connected databases are different.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-registry configuration --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;chinaRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;intlRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.154.177:9010&amp;#34;&lt;/span> default=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Quote Chinese station service --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;chinaHelloService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;chinaRegistry&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Reference international station service --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;intlHelloService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> registry=&lt;span style="color:#2aa198">&amp;#34;intlRegistry&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>If only the test environment temporarily needs to connect to two different registration centers, use vertical symbols to separate multiple different registration center addresses:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">&amp;lt;?xml version=&amp;#34;1.0&amp;#34; encoding=&amp;#34;UTF-8&amp;#34;?&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;beans&lt;/span> xmlns=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:xsi=&lt;span style="color:#2aa198">&amp;#34;http://www.w3.org/2001/XMLSchema-instance&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xmlns:dubbo=&lt;span style="color:#2aa198">&amp;#34;http://dubbo.apache.org/schema/dubbo&amp;#34;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> xsi:schemaLocation=&lt;span style="color:#2aa198">&amp;#34;http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema /dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd&amp;#34;&lt;/span>&lt;span style="color:#268bd2">&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:application&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;world&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Multi-registry configuration, separated by a vertical sign means connecting to multiple different registries at the same time, and multiple cluster addresses of the same registrant are separated by commas --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090|10.20.154.177:9010&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">&amp;lt;!-- Reference service --&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;helloService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.alibaba.hello.api.HelloService&amp;#34;&lt;/span> version=&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;/beans&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="footnotes" role="doc-endnotes">
&lt;hr>
&lt;ol>
&lt;li id="fn:1">
&lt;p>You can extend the registry by yourself, see: &lt;a href="../../../reference-manual/spi/description/registry">Registry Extension&lt;/a>&amp;#160;&lt;a href="#fnref:1" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;/ol>
&lt;/div></description></item><item><title>Docs3-V2: Local Stub</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-stub/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-stub/</guid><description>
&lt;h2 id="feature-description">Feature description:&lt;/h2>
&lt;p>After the remote service, the client usually only has the interface, and the implementation is all on the server side, but the provider sometimes wants to execute some logic on the client side.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/stub.jpg" alt="/user-guide/images/stub.jpg">&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Do ThreadLocal cache, verify parameters in advance, forge fault-tolerant data after call failure, etc. At this time, you need to bring a Stub in the API, and the client generates a Proxy instance, which will pass the Proxy to the Stub through the constructor &lt;sup id="fnref:1">&lt;a href="#fn:1" class="footnote-ref" role="doc-noteref">1&lt;/a>&lt;/sup>, and then pass the The Stub is exposed to the user, and the Stub can decide whether to call the Proxy.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="spring-configuration-file-configuration">spring configuration file configuration&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:consumer&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> stub=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>or&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:consumer&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> stub=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarServiceStub&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="provide-stub-implementation-2">Provide Stub implementation &lt;sup id="fnref:2">&lt;a href="#fn:2" class="footnote-ref" role="doc-noteref">2&lt;/a>&lt;/sup>&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com.foo&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">BarServiceStub&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> BarService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">private&lt;/span> &lt;span style="color:#268bd2">final&lt;/span> BarService barService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// The constructor passes in the real remote proxy object
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">BarServiceStub&lt;/span>&lt;span style="color:#719e07">(&lt;/span>BarService barService&lt;span style="color:#719e07">){&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">this&lt;/span>&lt;span style="color:#719e07">.&lt;/span> barService &lt;span style="color:#719e07">=&lt;/span> barService&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// This code is executed on the client side, you can do ThreadLocal local cache on the client side, or pre-verify whether the parameters are legal, etc.
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> barService&lt;span style="color:#719e07">.&lt;/span>sayHello&lt;span style="color:#719e07">(&lt;/span>name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>Exception e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// You are fault tolerant and can do any AOP interception
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;fault tolerance data&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;div class="footnotes" role="doc-endnotes">
&lt;hr>
&lt;ol>
&lt;li id="fn:1">
&lt;p>Stub must have a constructor that can be passed to Proxy.&amp;#160;&lt;a href="#fnref:1" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;li id="fn:2">
&lt;p>Next to the interface put a Stub implementation that implements the BarService interface and has a constructor that passes in the remote BarService instance.&amp;#160;&lt;a href="#fnref:2" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;/ol>
&lt;/div></description></item><item><title>Docs3-V2: Echo Test</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/echo-service/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/echo-service/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The echo test is used to detect whether the service is available. The echo test is performed according to the normal request process. It can test whether the entire call is smooth and can be used for monitoring.&lt;/p>
&lt;h2 id="reference-use-case">Reference use case&lt;/h2>
&lt;p>&lt;a href="https://github.com/apache/dubbo-samples/tree/master/2-advanced/dubbo-samples-echo">https://github.com/apache/dubbo-samples/tree/master/dubbo-samples-echo&lt;/a>&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>All services automatically implement the &lt;code>EchoService&lt;/code> interface, just cast any service reference to &lt;code>EchoService&lt;/code> to use it.&lt;/p>
&lt;h3 id="spring-configuration">Spring configuration&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;memberService&amp;#34;&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.xxx.MemberService&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="code">code&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// remote service reference
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>MemberService memberService &lt;span style="color:#719e07">=&lt;/span> ctx&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getBean&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;memberService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>EchoService echoService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">(&lt;/span>EchoService&lt;span style="color:#719e07">)&lt;/span> memberService&lt;span style="color:#719e07">;&lt;/span> &lt;span style="color:#586e75">// Mandatory transformation to EchoService
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// echo test availability
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>String status &lt;span style="color:#719e07">=&lt;/span> echoService&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">$echo&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;OK&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">assert&lt;/span>&lt;span style="color:#719e07">(&lt;/span>status&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">equals&lt;/span>&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;OK&amp;#34;&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Call Information Record</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/accesslog/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/accesslog/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The log in dubbo3 is divided into log adaptation and access log. If you want to record each request information, you can enable the access log, which is similar to the apache access log.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>Based on audit needs, etc. similar to nginx accesslog output, etc.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="log4j-log">log4j log&lt;/h3>
&lt;p>Output access logs to the current application&amp;rsquo;s log4j log&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> accesslog=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="specify-the-file">specify the file&lt;/h3>
&lt;p>Output the access log to the specified file&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> accesslog=&lt;span style="color:#2aa198">&amp;#34;http://10.20.160.198/wiki/display/dubbo/foo/bar.log&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;blockquote>
&lt;p>The log volume is relatively large, please pay attention to the disk capacity.&lt;/p>
&lt;/blockquote></description></item><item><title>Docs3-V2: Achieving generalization (server-side generalization)</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/generic-service/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/generic-service/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The universal interface implementation method is mainly used when there is no API interface and model classifier on the server side. All POJOs in the parameters and return values are represented by Map, which is usually used for framework integration. For example, to implement a general remote service Mock framework, you can All service requests are handled by implementing the GenericService interface.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;p>Implement the &lt;code>GenericService&lt;/code> interface in Java code&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">package&lt;/span> com.foo&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">MyGenericService&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> GenericService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> Object &lt;span style="color:#268bd2">$invoke&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String methodName&lt;span style="color:#719e07">,&lt;/span> String&lt;span style="color:#719e07">[]&lt;/span> parameterTypes&lt;span style="color:#719e07">,&lt;/span> Object&lt;span style="color:#719e07">[]&lt;/span> args&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#268bd2">throws&lt;/span> GenericException &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">if&lt;/span> &lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;sayHello&amp;#34;&lt;/span>&lt;span style="color:#719e07">.&lt;/span>equals&lt;span style="color:#719e07">(&lt;/span>methodName&lt;span style="color:#719e07">))&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;Welcome &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> args&lt;span style="color:#719e07">[&lt;/span>0&lt;span style="color:#719e07">];&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="exposing-generic-implementations-via-spring">Exposing generic implementations via Spring&lt;/h3>
&lt;p>Declare the implementation of the service in the Spring configuration&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;genericService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;com. foo. MyGenericService&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;com.foo.BarService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;genericService&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="expose-the-generalization-implementation-through-the-api">Expose the generalization implementation through the API&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">...&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Use org.apache.dubbo.rpc.service.GenericService to replace all interface implementations
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>GenericService xxxService &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> XxxGenericService&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// This instance is very heavy, and it encapsulates all connections with the registry and service providers, please cache
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;&lt;/span> service &lt;span style="color:#719e07">=&lt;/span> &lt;span style="color:#719e07">new&lt;/span> ServiceConfig&lt;span style="color:#719e07">&amp;lt;&lt;/span>GenericService&lt;span style="color:#719e07">&amp;gt;();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// Weakly typed interface name
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>service&lt;span style="color:#719e07">.&lt;/span>setInterface&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;com.xxx.XxxService&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>service&lt;span style="color:#719e07">.&lt;/span>setVersion&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;1.0.0&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// point to a generic service implementation
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>service&lt;span style="color:#719e07">.&lt;/span>setRef&lt;span style="color:#719e07">(&lt;/span>xxxService&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">// expose and register services
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span>service&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">export&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Asynchronous execution</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/async-execute-on-provider/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/async-execute-on-provider/</guid><description>
&lt;div class="pageinfo pageinfo-primary">
&lt;p>This document is no longer maintained. You are currently viewing a snapshot version. If you want to see the latest version of the documentation, see &lt;a href="https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/attachment/">Latest Version&lt;/a>.&lt;/p>
&lt;/div>
&lt;p>The asynchronous execution of the provider side switches the blocked business from Dubbo&amp;rsquo;s internal thread pool to the business-defined thread, avoiding excessive occupation of the Dubbo thread pool, and helping to avoid the mutual influence between different services. Asynchronous execution is tantamount to saving resources or improving RPC response performance, because if business execution needs to be blocked, there is always a thread to be responsible for execution.&lt;/p>
&lt;div class="alert alert-warning" role="alert">
&lt;h4 class="alert-heading">Attention&lt;/h4>
&lt;p>The asynchronous execution on the Provider side and the asynchronous call on the Consumer side are independent of each other, and you can configure both ends in any orthogonal combination&lt;/p>
&lt;ul>
&lt;li>Consumer Synchronization - Provider Synchronization&lt;/li>
&lt;li>Consumer asynchronous - Provider synchronous&lt;/li>
&lt;li>Consumer synchronous - Provider asynchronous&lt;/li>
&lt;li>Consumer asynchronous - Provider asynchronous&lt;/li>
&lt;/ul>
&lt;/div>
&lt;h2 id="define-the-interface-of-completablefuture-signature">Define the interface of CompletableFuture signature&lt;/h2>
&lt;p>Service interface definition:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">AsyncService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Service implementation:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">AsyncServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> AsyncService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">@Override&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> CompletableFuture&lt;span style="color:#719e07">&amp;lt;&lt;/span>String&lt;span style="color:#719e07">&amp;gt;&lt;/span> &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> RpcContext savedContext &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">getContext&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// It is recommended to provide a custom thread pool for supplyAsync and avoid using the JDK public thread pool
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> &lt;span style="color:#719e07">return&lt;/span> CompletableFuture&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">supplyAsync&lt;/span>&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> System&lt;span style="color:#719e07">.&lt;/span>out&lt;span style="color:#719e07">.&lt;/span>println&lt;span style="color:#719e07">(&lt;/span>savedContext&lt;span style="color:#719e07">.&lt;/span>getAttachment&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;consumer-key1&amp;#34;&lt;/span>&lt;span style="color:#719e07">));&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>5000&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#2aa198">&amp;#34;async response from provider.&amp;#34;&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">});&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Through &lt;code>return CompletableFuture.supplyAsync()&lt;/code>, the business execution has been switched from the Dubbo thread to the business thread, avoiding the blocking of the Dubbo thread pool.&lt;/p>
&lt;h2 id="using-asynccontext">Using AsyncContext&lt;/h2>
&lt;p>Dubbo provides an asynchronous interface &lt;code>AsyncContext&lt;/code> similar to Servlet 3.0, which can also implement asynchronous execution on the Provider side without the CompletableFuture signature interface.&lt;/p>
&lt;p>Service interface definition:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">interface&lt;/span> &lt;span style="color:#268bd2">AsyncService&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Service exposure is exactly the same as ordinary services:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;bean&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span> class=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.governance.impl.AsyncServiceImpl&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> interface=&lt;span style="color:#2aa198">&amp;#34;org.apache.dubbo.samples.governance.api.AsyncService&amp;#34;&lt;/span> ref=&lt;span style="color:#2aa198">&amp;#34;asyncService&amp;#34;&lt;/span>&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Service implementation:&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">public&lt;/span> &lt;span style="color:#268bd2">class&lt;/span> &lt;span style="color:#268bd2">AsyncServiceImpl&lt;/span> &lt;span style="color:#268bd2">implements&lt;/span> AsyncService &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">public&lt;/span> String &lt;span style="color:#268bd2">sayHello&lt;/span>&lt;span style="color:#719e07">(&lt;/span>String name&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#268bd2">final&lt;/span> AsyncContext asyncContext &lt;span style="color:#719e07">=&lt;/span> RpcContext&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">startAsync&lt;/span>&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">new&lt;/span> Thread&lt;span style="color:#719e07">(()&lt;/span> &lt;span style="color:#719e07">-&amp;gt;&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// If you want to use the context, it must be executed in the first sentence
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> asyncContext&lt;span style="color:#719e07">.&lt;/span>signalContextSwitch&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">try&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> Thread&lt;span style="color:#719e07">.&lt;/span> &lt;span style="color:#268bd2">sleep&lt;/span>&lt;span style="color:#719e07">(&lt;/span>500&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span> &lt;span style="color:#719e07">catch&lt;/span> &lt;span style="color:#719e07">(&lt;/span>InterruptedException e&lt;span style="color:#719e07">)&lt;/span> &lt;span style="color:#719e07">{&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> e&lt;span style="color:#719e07">.&lt;/span>printStackTrace&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#586e75">// write back the response
&lt;/span>&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#586e75">&lt;/span> asyncContext&lt;span style="color:#719e07">.&lt;/span>write&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#2aa198">&amp;#34;Hello &amp;#34;&lt;/span> &lt;span style="color:#719e07">+&lt;/span> name &lt;span style="color:#719e07">+&lt;/span> &lt;span style="color:#2aa198">&amp;#34;, response from provider.&amp;#34;&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}).&lt;/span>start&lt;span style="color:#719e07">();&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">return&lt;/span> &lt;span style="color:#cb4b16">null&lt;/span>&lt;span style="color:#719e07">;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span> &lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#719e07">}&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Local call</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-call/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/local-call/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>The local call uses the injvm protocol, which is a pseudo-protocol. It does not open ports, does not initiate remote calls, and is only directly associated in the JVM, but executes Dubbo&amp;rsquo;s Filter chain.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;p>When we need to call a remote service, the remote service has not been developed yet, and similar services are implemented locally using the injvm protocol. When calling this service, we can call our local implementation service.&lt;/p>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="define-the-injvm-protocol">Define the injvm protocol&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:protocol&lt;/span> name=&lt;span style="color:#2aa198">&amp;#34;injvm&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="set-the-default-protocol">Set the default protocol&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:provider&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;injvm&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="set-service-protocol">Set service protocol&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> protocol=&lt;span style="color:#2aa198">&amp;#34;injvm&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="prioritize-the-use-of-injvm">Prioritize the use of injvm&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:consumer&lt;/span> injvm=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> ...&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:provider&lt;/span> injvm=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> ...&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;strong>or&lt;/strong>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> injvm=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> ...&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> injvm=&lt;span style="color:#2aa198">&amp;#34;true&amp;#34;&lt;/span> ...&lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h4 id="notice">Notice:&lt;/h4>
&lt;p>Dubbo from &lt;code>2.2.0&lt;/code>, each service will be exposed locally by default, and can be referenced locally without any configuration. If you do not want the service to be exposed remotely, you only need to set the protocol to injvm in the provider. **&lt;/p>
&lt;h3 id="automatic-exposure">Automatic exposure&lt;/h3>
&lt;p>Starting with &lt;code>2.2.0&lt;/code>, every service is exposed locally by default. When referencing services, local services are preferred by default. If you want to reference remote services, you can use the following configuration to force references to remote services.&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:reference&lt;/span> ... scope=&lt;span style="color:#2aa198">&amp;#34;remote&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h3 id="dynamic-configuration-call-behavior">Dynamic configuration call behavior&lt;/h3>
&lt;p>Starting with&amp;rsquo; 3.2&amp;rsquo;, the api provided by Dubbo allows users to dynamically configure whether a single call is a local call or a remote call, and when it is not configured, the local service will be referenced first by default.&lt;/p>
&lt;p>&lt;strong>Configure a single call as a remote call.&lt;/strong>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>setLocalInvoke&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">false&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;strong>Configure a single call as a local call.&lt;/strong>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-java" data-lang="java">&lt;span style="display:flex;">&lt;span>RpcContext&lt;span style="color:#719e07">.&lt;/span>getServiceContext&lt;span style="color:#719e07">().&lt;/span>setLocalInvoker&lt;span style="color:#719e07">(&lt;/span>&lt;span style="color:#cb4b16">true&lt;/span>&lt;span style="color:#719e07">);&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Delayed Exposure</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/delay-publish/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/delay-publish/</guid><description>
&lt;p>If your service needs warm-up time, such as initializing the cache, waiting for related resources to be in place, etc., you can use delay for delayed exposure. In Dubbo version 2.6.5, we made minor adjustments to the service delay exposure logic, and postponed the countdown action for services that require delay exposure (delay &amp;gt; 0) until Spring initialization is complete. You will not feel this change while using Dubbo, so please feel free to use it.&lt;/p>
&lt;h2 id="versions-before-dubbo-265">Versions before Dubbo 2.6.5&lt;/h2>
&lt;p>Delay until Spring initialization completes before exposing services&lt;sup id="fnref:1">&lt;a href="#fn:1" class="footnote-ref" role="doc-noteref">1&lt;/a>&lt;/sup>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> delay=&lt;span style="color:#2aa198">&amp;#34;-1&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>Expose service with 5 second delay&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> delay=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="dubbo-265-and-later-versions">Dubbo 2.6.5 and later versions&lt;/h2>
&lt;p>All services will be exposed after Spring initialization is complete. If you do not need to delay exposing services, you do not need to configure delay.&lt;/p>
&lt;p>Expose service with 5 second delay&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:service&lt;/span> delay=&lt;span style="color:#2aa198">&amp;#34;5000&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;h2 id="spring-2x-initialization-deadlock-problem">Spring 2.x initialization deadlock problem&lt;/h2>
&lt;h3 id="triggering-conditions">Triggering conditions&lt;/h3>
&lt;p>When Spring resolves to &lt;code>&amp;lt;dubbo:service /&amp;gt;&lt;/code>, the service has been exposed, and Spring is still initializing other beans. If a request comes in at this time, and there is a usage of calling &lt;code>applicationContext.getBean()&lt;/code> in the implementation class of the service.&lt;/p>
&lt;ol>
&lt;li>
&lt;p>The applicationContext.getBean() call of the requesting thread first synchronizes the singletonObjects to determine whether the Bean exists, and initializes the synchronization beanDefinitionMap if it does not exist, and then synchronizes the singletonObjects again to write the Bean instance cache.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/lock-get-bean.jpg" alt="deadlock">&lt;/p>
&lt;/li>
&lt;li>
&lt;p>The Spring initialization thread, because it does not need to judge the existence of the bean, directly synchronizes the beanDefinitionMap to initialize, and synchronizes singletonObjects to write the bean instance cache.&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/lock-init-context.jpg" alt="/user-guide/images/lock-init-context.jpg">&lt;/p>
&lt;p>This causes the getBean thread to lock singletonObjects first, then beanDefinitionMap, and singletonObjects again.
The Spring initialization thread first locks beanDefinitionMap and then singletonObjects. The reverse lock leads to thread deadlock, unable to provide services, and unable to start.&lt;/p>
&lt;/li>
&lt;/ol>
&lt;h3 id="workaround">Workaround&lt;/h3>
&lt;ol>
&lt;li>It is strongly recommended not to call applicationContext.getBean() in the service implementation class, and all use Spring beans by IoC injection.&lt;/li>
&lt;li>If you really want to call getBean(), you can load the Dubbo configuration at the end of Spring.&lt;/li>
&lt;li>If you don’t want to depend on the configuration order, you can use &lt;code>&amp;lt;dubbo:provider delay=”-1” /&amp;gt;&lt;/code> to make Dubbo expose the service after the Spring container is initialized.&lt;/li>
&lt;li>If you use getBean() extensively, it is equivalent to degenerating Spring into a factory mode, and you can isolate Dubbo&amp;rsquo;s services into a separate Spring container.&lt;/li>
&lt;/ol>
&lt;div class="footnotes" role="doc-endnotes">
&lt;hr>
&lt;ol>
&lt;li id="fn:1">
&lt;p>Trigger exposure based on Spring&amp;rsquo;s ContextRefreshedEvent event&amp;#160;&lt;a href="#fnref:1" class="footnote-backref" role="doc-backlink">&amp;#x21a9;&amp;#xfe0e;&lt;/a>&lt;/p>
&lt;/li>
&lt;/ol>
&lt;/div></description></item><item><title>Docs3-V2: Sign Up Only</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/registry-only/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/registry-only/</guid><description>
&lt;h2 id="feature-description">Feature description&lt;/h2>
&lt;p>If there are two mirroring environments and two registries, one service is only deployed in one of the registries, and the other registry has not yet been deployed, and other applications in the two registries need to rely on this service. At this time, the service provider can only register the service to another registration center, but not subscribe to the service from another registration center.&lt;/p>
&lt;h2 id="scenes-to-be-used">scenes to be used&lt;/h2>
&lt;h2 id="how-to-use">How to use&lt;/h2>
&lt;h3 id="disable-subscription-configuration">Disable subscription configuration&lt;/h3>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;hzRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.153.10:9090&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;qdRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090&amp;#34;&lt;/span> subscribe=&lt;span style="color:#2aa198">&amp;#34;false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div>&lt;p>&lt;strong>or&lt;/strong>&lt;/p>
&lt;div class="highlight">&lt;pre tabindex="0" style="color:#93a1a1;background-color:#002b36;-moz-tab-size:4;-o-tab-size:4;tab-size:4;">&lt;code class="language-xml" data-lang="xml">&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;hzRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.153.10:9090&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;span style="display:flex;">&lt;span>&lt;span style="color:#268bd2">&amp;lt;dubbo:registry&lt;/span> id=&lt;span style="color:#2aa198">&amp;#34;qdRegistry&amp;#34;&lt;/span> address=&lt;span style="color:#2aa198">&amp;#34;10.20.141.150:9090?subscribe=false&amp;#34;&lt;/span> &lt;span style="color:#268bd2">/&amp;gt;&lt;/span>
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/div></description></item><item><title>Docs3-V2: Distributed transaction support</title><link>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/distributed-transaction/</link><pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate><guid>https://dubbo.apache.org/en/docs3-v2/java-sdk/advanced-features-and-usage/service/distributed-transaction/</guid><description>
&lt;p>Distributed transactions are implemented based on the JTA/XA specification.&lt;/p>
&lt;p>&lt;strong>two-phase commit&lt;/strong>&lt;/p>
&lt;p>&lt;img src="https://dubbo.apache.org/imgs/user/jta-xa.jpg" alt="/user-guide/images/jta-xa.jpg">&lt;/p>
&lt;p>In Dubbo, you can use [seata](/zh-cn/blog/2019/01/17/How to use seata to ensure the consistency between dubbo microservices/) to complete the support for distributed transactions.&lt;/p></description></item></channel></rss>