| <div class="wiki-content maincontent"><div class="confluence-information-macro confluence-information-macro-information"><span class="aui-icon aui-icon-small aui-iconfont-info confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>This documentation only applies when the Stomp client is connected to an ActiveMQ Broker v5.4 and above.</p></div></div> |
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| ActiveMQ from version <strong>5.4</strong> has an optional persistent scheduler built into the ActiveMQ message broker. It is enabled by setting the broker <strong>schedulerSupport</strong> attribute to true in the <a shape="rect" class="unresolved" href="#">xml configuration</a>. <br clear="none"> |
| An ActiveMQ client can take advantage of a delayed delivery by using the following message properties: |
| |
| <div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>type </p></th><th colspan="1" rowspan="1" class="confluenceTh"><p> description </p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>AMQ_SCHEDULED_DELAY</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> long </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> The time in milliseconds that a message will wait before being scheduled to be delivered by the broker</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>AMQ_SCHEDULED_PERIOD </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>long </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> The time in milliseconds to wait after the start time to wait before scheduling the message again</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>AMQ_SCHEDULED_REPEAT </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>int </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> The number of times to repeat scheduling a message for delivery</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>AMQ_SCHEDULED_CRON </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>String </p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> Use a Cron entry to set the schedule</p></td></tr></tbody></table></div> |
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| |
| <p>For example, to have a message scheduled for delivery in 60 seconds - you would need to set the <em>AMQ_SCHEDULED_DELAY</em> property:</p> |
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| <div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl"> |
| <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ |
| IMessageProducer producer = session.CreateProducer(destination); |
| ITextMessage message = session.CreateTextMessage("test msg"); |
| long time = 60 * 1000; |
| message.Properties["AMQ_SCHEDULED_DELAY"] = time; |
| producer.Send(message); |
| ]]></script> |
| </div></div> |
| |
| <p>You can set a message to wait with an initial delay, and the repeat delivery 10 times, waiting 10 seconds between each re-delivery:</p> |
| |
| <div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl"> |
| <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ |
| IMessageProducer producer = session.CreateProducer(destination); |
| ITextMessage message = session.CreateTextMessage("test msg"); |
| long delay = 30 * 1000; |
| long period = 10 * 1000; |
| int repeat = 9; |
| message.Properties["AMQ_SCHEDULED_DELAY"] = delay; |
| message.Properties["AMQ_SCHEDULED_PERIOD"] = period; |
| message.Properties["AMQ_SCHEDULED_REPEAT"] = repeat; |
| producer.Send(message); |
| ]]></script> |
| </div></div> |
| |
| |
| <p>You can also use <a shape="rect" class="external-link" href="http://en.wikipedia.org/wiki/Cron" rel="nofollow">CRON</a> to schedule a message, for example, if you want a message scheduled to be delivered every hour, you would need to set the CRON entry to be - <em>0 * * * *</em> - e.g.</p> |
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| <div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl"> |
| <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ |
| IMessageProducer producer = session.CreateProducer(destination); |
| ITextMessage message = session.CreateTextMessage("test msg"); |
| message.Properties["AMQ_SCHEDULED_CRON"] = "0 * * * *"; |
| producer.Send(message); |
| ]]></script> |
| </div></div> |
| |
| <p>CRON scheduling takes priority over using message delay - however, if a repeat and period is set with a CRON entry, the ActiveMQ scheduler will schedule delivery of the message for every time the CRON entry fires. Easier to explain with an example. Supposing that you want a message to be delivered 10 times, with a one second delay between each message - and you wanted this to happen every hour - you'd do this:</p> |
| |
| <div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl"> |
| <script class="brush: java; gutter: false; theme: Default" type="syntaxhighlighter"><![CDATA[ |
| IMessageProducer producer = session.CreateProducer(destination); |
| ITextMessage message = session.CreateTextMessage("test msg"); |
| message.Properties["AMQ_SCHEDULED_CRON"] = "0 * * * *"; |
| message.Properties["AMQ_SCHEDULED_DELAY"] = 1000; |
| message.Properties["AMQ_SCHEDULED_PERIOD"] = 1000; |
| message.Properties["AMQ_SCHEDULED_REPEAT"] = 9; |
| producer.Send(message); |
| ]]></script> |
| </div></div></div> |
| |
