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| |
| <document> |
| <properties> |
| <title>Apache Synapse - Sample 156</title> |
| </properties> |
| <body> |
| <section name="Sample 156: Service Integration with Specifying the Receiving Sequence"> |
| <div class="xmlConf"><definitions xmlns="http://ws.apache.org/ns/synapse"> |
| <localEntry key="sec_policy" src="file:repository/conf/sample/resources/policy/policy_3.xml"/> |
| <proxy name="StockQuoteProxy"> |
| <target> |
| <inSequence> |
| <enrich> |
| <source type="body"/> |
| <target type="property" property="REQUEST"/> |
| </enrich> |
| |
| <send receive="SimpleServiceSeq"> |
| <endpoint name="secure"> |
| <address uri="http://localhost:9000/services/SecureStockQuoteService"> |
| <enableSec policy="sec_policy"/> |
| </address> |
| </endpoint> |
| </send> |
| </inSequence> |
| <outSequence> |
| <drop/> |
| </outSequence> |
| </target> |
| </proxy> |
| |
| <sequence name="SimpleServiceSeq"> |
| <property name="SECURE_SER_AMT" expression="//ns:getQuoteResponse/ns:return/ax21:last" |
| xmlns:ns="http://services.samples" xmlns:ax21="http://services.samples/xsd"/> |
| <log level="custom"> |
| <property name="SecureStockQuoteService-Amount" expression="get-property('SECURE_SER_AMT')"/> |
| </log> |
| <enrich> |
| <source type="body"/> |
| <target type="property" property="SecureService_Res"/> |
| </enrich> |
| <enrich> |
| <source type="property" property="REQUEST"/> |
| <target type="body"/> |
| </enrich> |
| <send receive="ClientOutSeq"> |
| <endpoint name="SimpleStockQuoteService"> |
| <address uri="http://localhost:9000/services/SimpleStockQuoteService"/> |
| </endpoint> |
| </send> |
| </sequence> |
| |
| <sequence name="ClientOutSeq"> |
| <property name="SIMPLE_SER_AMT" expression="//ns:getQuoteResponse/ns:return/ax21:last" |
| xmlns:ns="http://services.samples" xmlns:ax21="http://services.samples/xsd"/> |
| <log level="custom"> |
| <property name="SimpleStockQuoteService-Amount" expression="get-property('SIMPLE_SER_AMT')"/> |
| </log> |
| <enrich> |
| <source type="body"/> |
| <target type="property" property="SimpleService_Res"/> |
| </enrich> |
| |
| <filter xpath="fn:number(get-property('SIMPLE_SER_AMT')) > fn:number(get-property('SECURE_SER_AMT'))"> |
| <then> |
| <log> |
| <property name="StockQuote" value="SecureStockQuoteService"/> |
| </log> |
| <enrich> |
| <source type="property" property="SecureService_Res"/> |
| <target type="body"/> |
| </enrich> |
| </then> |
| <else> |
| <log> |
| <property name="StockQuote" value="SimpleStockQuoteService"/> |
| </log> |
| </else> |
| </filter> |
| <send/> |
| </sequence> |
| </definitions></div> |
| <subsection name="Objective"> |
| <p> |
| Synapse is capable of mediating requests among multiple services and managing |
| complex message flows thereby acting as a lightweight orchestration engine. This |
| sample demonstrates how to easily integrate multiple services with Synapse using |
| the 'receiving sequence' feature of Synapse. |
| </p> |
| </subsection> |
| <subsection name="Pre-requisites"> |
| <p> |
| <ul> |
| <li> |
| Deploy the SimpleStockQuoteService in the sample Axis2 server |
| </li> |
| <li> |
| Deploy the SecureStockQuoteService in the sample Axis2 server and start Axis2 |
| </li> |
| <li> |
| Start Synapse using the configuration numbered 156 (repository/conf/sample/synapse_sample_156.xml) |
| <div class="command"> |
| Unix/Linux: sh synapse.sh -sample 156<br/> |
| Windows: synapse.bat -sample 156 |
| </div> |
| </li> |
| </ul> |
| </p> |
| </subsection> |
| <subsection name="Executing the Client"> |
| <p> |
| This sample includes a proxy service which first forwards the client request to |
| the SecureStockQuoteService. Once a response has been received from this service, |
| Synapse will turn around and invoke the SimpleStockQuoteService. To do this proxy |
| service must hold on to the original request in memory. This is done using an |
| enrich mediator. Once Synapse has received a response from the SimpleStockQuoteService |
| it will compare the two responses received from the two services and select the |
| one with the lower stock quote value. This response will be then sent to the |
| client. |
| </p> |
| <p> |
| The important feature to note here is the 'receive' attribute set on the 'send' |
| mediators. This tells Synapse that responses of those send operations should be |
| directed to the sequences referred by the 'receive' attribute. Therefore the |
| response from the SecureStockQuoteService is directed to the sequence named |
| 'SimpleServiceSeq'. Similarly the response from the SimpleStockQuoteService will |
| be handled by the sequence named 'ClientOutSeq'. |
| </p> |
| <p> |
| To try this out, execute the stock quote client as follows: |
| </p> |
| <div class="command">ant stockquote -Daddurl=http://localhost:8280/services/StockQuoteProxy</div> |
| <p> |
| You can confirm that Synapse invokes both services by going through the console |
| output of the Axis2 server. However Axis2 client will receive only one response |
| back. As far as the client is concerned, only one HTTP transaction is taking place. |
| But Synapse does multiple service invocations with the back-end to make the whole |
| integration scenario tick. |
| </p> |
| </subsection> |
| </section> |
| <p><a href="../samples.html">Back to Catalog</a></p> |
| </body> |
| </document> |
