Sample 851: Introduction to Synapse Splitter and Aggregator eip function templates

<definitions xmlns="http://ws.apache.org/ns/synapse"> <import xmlns="http://ws.apache.org/ns/synapse" name="EipLibrary" package="synapse.lang.eip" /> <proxy name="StockQuoteProxy" transports="https http" startOnLoad="true" trace="disable"> <target> <inSequence> <log level="custom"> <property name="text" value="splitterAggrigator"/> </log> <call-template target="synapse.lang.eip.splitter"> <with-param xmlns:m0="http://services.samples" name="iterate_exp" value="{{//m0:getQuote/m0:request}}"/> <with-param xmlns:m0="http://services.samples" name="attach_path" value="{{//m0:getQuote}}"/> <with-param name="attach_path_enabled" value="true"/> <with-param name="endpoint_uri" value="http://localhost:9000/services/SimpleStockQuoteService"/> </call-template> </inSequence> <outSequence> <call-template target="synapse.lang.eip.aggregator"> <with-param name="sequence_ref" value="enr"/> <with-param xmlns:m0="http://services.samples" name="aggregator_exp" value="{{//m0:return}}"/> <with-param name="oncomplete_seq_enabled" value="true"/> </call-template> </outSequence> </target> </proxy> <sequence xmlns="http://ws.apache.org/ns/synapse" name="enr"> <log level="custom"> <property name="text" value="seqhit"/> </log> <enrich> <source xmlns:m0="http://services.samples" clone="true" xpath="//m0:return[not(preceding-sibling::m0:return/m0:last &lt;= m0:last) and not(following-sibling::m0:return/m0:last &lt; m0:last)]"/> <target type="body"/> </enrich> <send/> </sequence> </definitions>

Objective

This sample is an introduction to Synapse Splitter and Aggregator eip function templates. This showcase the combined functionality of Splitter and Aggregator patterns.

Pre-requisites

  • Deploy the SimpleStockQuoteService in the sample Axis2 server and start Axis2
  • Start Synapse using the configuration numbered 851 (repository/conf/sample/synapse_sample_851.xml)
    Unix/Linux: sh synapse.sh -sample 851
    Windows: synapse.bat -sample 851

Executing the Client

In this sample, the message sent to Synapse will be splitted according to the given Xpath expression and does a synchronized call for the given endpoint and aggregates replies. Then mediates to the defined target sequence which filter the response which contains the best quote and send back to the client. Here it uses Splitter and Aggregator function templates.

Invoke the client as follows.

ant stockquote -Dtrpurl=http://localhost:8280/services/StockQuoteProxy -Ditr=4

The above command will send a request containing four fragments in it.

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