Sample 400: Message Splitting and Aggregating the Responses

Objective: Demonstrate the use of Iterate mediator to split the messages in to parts and process them asynchronously and then aggregate the responses coming in to ESB.

<definitions xmlns="http://ws.apache.org/ns/synapse">

    <proxy name="SplitAggregateProxy">
        <target>
            <inSequence>
                <iterate expression="//m0:getQuote/m0:request" preservePayload="true"
                         attachPath="//m0:getQuote"
                         xmlns:m0="http://services.samples">
                    <target>
                        <sequence>
                            <send>
                                <endpoint>
                                    <address
                                        uri="http://localhost:9000/services/SimpleStockQuoteService"/>
                                </endpoint>
                            </send>
                        </sequence>
                    </target>
                </iterate>
            </inSequence>
            <outSequence>
                <aggregate>
                    <onComplete expression="//m0:getQuoteResponse"
                                xmlns:m0="http://services.samples">
                        <send/>
                    </onComplete>
                </aggregate>
            </outSequence>
        </target>
    </proxy>
</definitions>

Prerequisites:

Deploy the SimpleStockQuoteService in sample Axis2 server and start it on port 9000.
Create the above configuration and deploy it in the WSO2 EI profile, see Working with WSO2 Integration Studio).

In this sample, the message sent to ESB has embedded with a number of elements of the same type in one message. When ESB received this message it will iterate through those elements and then sent to the specified endpoint. When all the responses appear in to ESB then those messages will be aggregated to form the resultant response and sent back to the client.

Invoke the client as follows.

ant stockquote -Daddurl=http://localhost:8280/services/SplitAggregateProxy -Ditr=4