Apache Synapse/WSO2 ESB calling a REST Endpoint

One of the features of Apache Synapse and the WSO2 ESB (Which is Apache Synapse + Monitoring + Management + WSO2 Registry Integration) is that it can change message formats.

There was a question on the ESB-USER mailing list recently asking how you could receive a SOAP message and send out a REST message (HTTP POST serialized as application/x-www-form-urlencoded) to another service. In order to do this you simply need to set two properties on the message. The HTTP_Method to be used and the messageType to be used. The following is a complete synapse.xml

view plainprint?

1. <syn:definitions xmlns:syn="<a href="http://ws.apache.org/ns/synapse">http://ws.apache.org/ns/synapse</a>">  
2.   
3.     <syn:registry provider="org.wso2.esb.registry.ESBRegistry">  
4.   
5.         <syn:parameter name="root">file:registry/</syn:parameter>  
6.   
7.     </syn:registry>  
8.   
9.     <syn:proxy name="RESTProxy" startOnLoad="true">  
10.   
11.         <syn:target>  
12.   
13.             <syn:endpoint name="RESTEndpoint">  
14.   
15.                 <syn:address uri="<a href="http://localhost:7763/services/keith/test/foo">http://localhost:7763/services/keith/test/foo</a>"/>  
16.   
17.             </syn:endpoint>  
18.   
19.             <syn:inSequence>  
20.   
21.                 <syn:property name="messageType" value="application/x-www-form-urlencoded" scope="axis2"/>  
22.   
23.                 <syn:property name="HTTP_METHOD" value="post" scope="axis2"/>  
24.   
25.             </syn:inSequence>  
26.   
27.         </syn:target>  
28.   
29.     </syn:proxy>     
30.   
31.     <syn:sequence name="main">  
32.   
33.         <syn:send/>  
34.   
35.     </syn:sequence>  
36.   
37.     <syn:sequence name="fault">  
38.   
39.         <syn:log/>  
40.   
41.     </syn:sequence>  
42.   
43. </syn:definitions>  

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

    <syn:registry provider="org.wso2.esb.registry.ESBRegistry">

        <syn:parameter name="root">file:registry/</syn:parameter>

    </syn:registry>

    <syn:proxy name="RESTProxy" startOnLoad="true">

        <syn:target>

            <syn:endpoint name="RESTEndpoint">

                <syn:address uri="http://localhost:7763/services/keith/test/foo"/>

            </syn:endpoint>

            <syn:inSequence>

                <syn:property name="messageType" value="application/x-www-form-urlencoded" scope="axis2"/>

                <syn:property name="HTTP_METHOD" value="post" scope="axis2"/>

            </syn:inSequence>

        </syn:target>

    </syn:proxy>   

    <syn:sequence name="main">

        <syn:send/>

    </syn:sequence>

    <syn:sequence name="fault">

        <syn:log/>

    </syn:sequence>

</syn:definitions>

Here is the request sent into the ESB:

view plainprint?

1. POST /soap/RESTProxy/mediate HTTP/1.1  
2.   
3. Content-Type: application/soap+xml; charset=UTF-8; action="urn:anonOutInOp"  
4.   
5. User-Agent: WSO2 Mashup Server - Version 1.5.1  
6.   
7. Host: 127.0.0.1  
8.   
9. Content-Length: 191  
10.   
11.   
12.   
13. <?xml version='1.0' encoding='UTF-8'?>  
14.   
15.    <soapenv:Envelope xmlns:soapenv="<a href="http://www.w3.org/2003/05/soap-envelope">http://www.w3.org/2003/05/soap-envelope</a>">  
16.   
17.       <soapenv:Body>  
18.   
19.          <foo>  
20.   
21.             <param>keith</param>  
22.   
23.          </foo>  
24.   
25.       </soapenv:Body>  
26.   
27.    </soapenv:Envelope>  

POST /soap/RESTProxy/mediate HTTP/1.1

Content-Type: application/soap+xml; charset=UTF-8; action="urn:anonOutInOp"

User-Agent: WSO2 Mashup Server - Version 1.5.1

Host: 127.0.0.1

Content-Length: 191



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

   <soapenv:Envelope xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope">

      <soapenv:Body>

         <foo>

            <param>keith</param>

         </foo>

      </soapenv:Body>

   </soapenv:Envelope>

Here is its response (or Request sent out to the REST service):

view plainprint?

1. POST http://localhost:7763/services/keith/test/foo HTTP/1.1  
2. Host: 127.0.0.1  
3. Content-Type: application/x-www-form-urlencoded; charset=UTF-8;action="urn:anonOutInOp";  
4. Transfer-Encoding: chunked  
5. Connection: Keep-Alive  
6. User-Agent: Synapse-HttpComponents-NIO  
7.   
8. b  
9. param=keith  
10. 0  

POST http://localhost:7763/services/keith/test/foo HTTP/1.1
Host: 127.0.0.1
Content-Type: application/x-www-form-urlencoded; charset=UTF-8;action="urn:anonOutInOp";
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO

b
param=keith
0