Calling an asynchronous web service & waiting for a response

[Paul McCulloch]

I need to use an asynchronous web service from within a route. By asynch I
mean that the remote service will respond immediately to the HTTP request
with an acknowledgement, but the result of the request will be sent later
to an incoming web service.

I have implemented this via the Request-Reply EIP implemented for JMS, but
I was hoping for a mechanism with less moving parts. I've included routes
to demonstrate the problem & my solution.

Is there a more elegant solution?

Paul

       <camelContext trace="false" xmlns="
http://camel.apache.org/schema/spring";>
              <!-- client & server web services, with an asynchronous
server. We use JMS
                     to utilise the Request Response EIP (which as far as I
can see) can't
                     be utilised explicitly to wrap http  - perhaps as it
is inherently request-response anyway).
                     Looks like SOAP handles this via WS-Addressing with
the ReplyTo header
              -->
              <route id="asynch client">
                     <from uri="jetty:http://localhost:8888/asynchclient"/>
                    <setHeader
headerName="JMSCorrelationID"><simple>${headers.data}</simple></setHeader>
                    <to
uri="jms:queue:asynchclient?exchangePattern=InOut&amp;replyTo=asynchClientCallback"/>
                    <log message="Got Response from asynch server"/>

              </route>

              <route id="asynch client requester">
                   <from uri="jms:queue:asynchclient?disableReplyTo=true"/>
                    <to uri="jetty:
http://localhost:8889/asynchserver?bridgeEndpoint=true"; />
              </route>

              <route id="asynch client reciever">
                     <from uri="jetty:http://localhost:8888/asynchcallback
"/>
                     <setHeader
headerName="JMSCorrelationID"><simple>${headers.data}</simple></setHeader>
                     <inOnly uri="jms:queue:asynchClientCallback"/>
              </route>

              <route id="asynch server ack">
                     <from uri="jetty:http://localhost:8889/asynchserver"/>
                     <wireTap uri="direct:sendResponse"/>
                     <setBody><simple>OK</simple></setBody>
              </route>

              <route id="asynch server response">
                     <from uri="direct:sendResponse"/>
                     <delay><constant>10000</constant></delay>
                     <setBody><simple>{"data": ${headers.data}, "result":
"Some response for ${headers.data}"}</simple></setBody>
                     <setHeader
headerName="CamelHttpMethod"><constant>POST</constant></setHeader>
                     <to uri="jetty:
http://localhost:8888/asynchcallback?bridgeEndpoint=true"/>
              </route>
       </camelContext>