Adding http path parameters dynamically in wso2 esb

Question

We have a proxy service which uses jms transport to receive messages. The messages received need to be sent to a backend REST service using http POST. The following is done on the messages

1. xslt transformation to extract specific fields
2. set message type to application/json
3. send to the endpoint

The REST service endpoint needs to have a path parameter appended dynamically using one of the values that comes as part of the input message from jms. The url will look like http://<server-ip>/service/<client>. Here the value for the "client" comes as part of the message.

How can we dynamically add the path param using wso2 esb?

Answer 1

I believe what you are looking for is the REST_URL_POSTFIX property. If you set this property, the value will be appended to the rest endpoint url.

It can be defined as follows with the scope of axis2.

<property name="REST_URL_POSTFIX"
          expression="//client"
          scope="axis2"
          type="STRING"/>

An example on this can be found in this guide, Using REST with a Proxy Service.

EDIT: Following is example using a simple proxy with a POST request using curl. Providing as per the comments. Here, I'm invoking the jaxrs_basic rest service in WSO2 Application Server.

curl -H "Content-Type: application/xml" -H "Accept: application/json" -d "<Customer><name>KasunG</name></Customer>" http://localhost:8281/services/new1/

.

curl -H "Content-Type: application/json" -H "Accept: application/json" -d "{ 'Customer' : { 'name' : 'KasunG' } }  " http://localhost:8281/services/new1/

.

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="new1"
       transports="https http"
       startOnLoad="true"
       trace="disable">
   <description/>
   <target>
      <inSequence>
         <property name="REST_URL_POSTFIX"
                   value="customers"
                   scope="axis2"
                   type="STRING"/>
         <property name="ContentType" value="text/xml" scope="axis2" type="STRING"/>
         <switch source="$axis2:HTTP_METHOD">
            <case regex="GET">
               <property name="HTTP_METHOD" value="GET" scope="axis2" type="STRING"/>
            </case>
            <case regex="POST">
               <property name="messageType" value="application/json" scope="axis2"/>
               <property name="ContentType"
                         value="application/JSON"
                         scope="axis2"
                         type="STRING"/>
               <property name="HTTP_METHOD" value="POST" scope="axis2" type="STRING"/>
            </case>
            <default/>
         </switch>
         <send>
            <endpoint>
               <address uri="http://localhost:8888/jaxrs_basic/services/customers/customerservice"
                        format="rest"/>
            </endpoint>
         </send>
      </inSequence>
      <outSequence>
         <property name="messageType" value="application/json" scope="axis2"/>
         <send/>
      </outSequence>
   </target>
</proxy>