Mule 3 fork and join sample

gistfile1.xml

<?xml version="1.0" encoding="UTF-8"?>

<mule xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns:http="http://www.mulesoft.org/schema/mule/http"
	xmlns="http://www.mulesoft.org/schema/mule/core"
	xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:mulexml="http://www.mulesoft.org/schema/mule/xml"
	xmlns:spring="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	version="CE-3.3.0"
	xsi:schemaLocation="http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd 
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd 
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/xml http://www.mulesoft.org/schema/mule/xml/current/mule-xml.xsd ">

	<mulexml:namespace-manager>
		<mulexml:namespace uri="http://musicbrainz.org/ns/mmd-2.0#"
			prefix="mb" />
	</mulexml:namespace-manager>

	<flow name="workIn">

		<http:inbound-endpoint  host="127.0.0.1"
			port="8080" path="work" exchange-pattern="request-response">
		</http:inbound-endpoint>
		
		<expression-transformer expression="#[header:INBOUND:name]" doc:name="Extract query parameter"/>
		
		<http:outbound-endpoint host="musicbrainz.org"
			port="80" path="ws/2/artist?query=#[payload:]" method="GET" doc:name="Search for artists' MBID " />
		
		<splitter evaluator="xpath" expression="/mb:metadata/mb:artist-list/mb:artist"
			doc:name="Split by found artists" />
			
		<mulexml:xpath-extractor-transformer
			expression="/mb:artist/@id" resultType="STRING" doc:name="Extract MBID"/>

		<collection-aggregator doc:name="Aggregate collection of MBIDs"/>

		<request-reply storePrefix="workStore" doc:name="Put collection of MBIDs on queue for processing">
			<vm:outbound-endpoint path="dispatchIn">
				<message-properties-transformer
					scope="outbound">
					<delete-message-property key="MULE_REPLYTO" />
				</message-properties-transformer>
			</vm:outbound-endpoint>

			<vm:inbound-endpoint path="dispatchOut" />
		</request-reply>
		
		<custom-transformer class="com.examples.mule.XMLAggregator" doc:name="Merge response in resulting XML" />
		
		<mulexml:dom-to-xml-transformer/>		
		
	</flow>

	<flow name="workDispatcher">
		<vm:inbound-endpoint path="dispatchIn" />
		<collection-splitter enableCorrelation="ALWAYS" />
		<flow-ref name="workWorker" />
	</flow>

	<flow name="workWorker">
		
		<message-properties-transformer scope="invocation" doc:name="Remember correlation">
			<add-message-property value="#[header:OUTBOUND:MULE_CORRELATION_ID]" key="cid" />
			<add-message-property value="#[header:OUTBOUND:MULE_CORRELATION_GROUP_SIZE]" key="cgs" />
		</message-properties-transformer>
		
		<all>
			<processor-chain> 
				<http:outbound-endpoint host="ws.audioscrobbler.com"
					port="80"
					path="2.0/?method=artist.getinfo&amp;mbid=#[payload:]&amp;api_key=b25b959554ed76058ac220b7b2e0a026"
					method="GET" doc:name="Query LastFm fro artist's bio" />
				<mulexml:xpath-extractor-transformer expression="/lfm/artist/bio" resultType="NODE"/>
			</processor-chain>
			
			<processor-chain>
				<http:outbound-endpoint host="ws.audioscrobbler.com"
					port="80"
					path="2.0/?method=artist.getevents&amp;mbid=#[payload:]&amp;api_key=b25b959554ed76058ac220b7b2e0a026"
					method="GET" doc:name="Query LastFm for artist's events" />
				<mulexml:xpath-extractor-transformer expression="/lfm/events" resultType="NODE"/>
			</processor-chain>

			<processor-chain>
				<http:outbound-endpoint host="musicbrainz.org"
					port="80" path="ws/2/artist/#[payload:]?inc=releases+media" method="GET"
					doc:name="Query MusicBrainz for artist's releases" />
				<mulexml:xpath-extractor-transformer expression="/metadata/artist/release-list" resultType="NODE"/>
			</processor-chain>
		</all>
		
		<message-properties-transformer scope="outbound">
			<add-message-property value="#[header:INVOCATION:cid]" key="MULE_CORRELATION_ID" />
			<add-message-property value="#[header:INVOCATION:cgs]" key="MULE_CORRELATION_GROUP_SIZE" />
		</message-properties-transformer>
											
		<vm:outbound-endpoint path="aggregatorIn" />
	</flow>

	<flow name="workAggregator">
		<vm:inbound-endpoint path="aggregatorIn" />

		<collection-aggregator />

		<vm:outbound-endpoint path="dispatchOut" />
	</flow>


</mule>