Description of problem:

I have following REST server:

<cxf:rsServer
    id="rsJsonServer"
    address="http://localhost:58002/restjson"
    serviceClass="org.kie.jax.rs.CommandExecutorImpl">
    <cxf:providers>
      <bean class="org.kie.jax.rs.CommandMessageBodyReader" />
    </cxf:providers>
  </cxf:rsServer>

for that I've created this camel route:

<route id="restJsonGW">
      <from uri="cxfrs://bean://rsJsonServer" />
      <policy ref="kiePolicy">
        <unmarshal ref="json" />
        <to uri="kie:ksession1" />
        <marshal ref="json" />
      </policy>
    </route>

When I work just with business rules and objects, the responses are right. The problem is when I start a business process. For xstream I always receive a result with process instance id but not for json. The result is there but without any values. To marshall the batch xml, I use BatchExecutionHelper.newJSonMarshaller().

String outIdentifier = "taskProcess";
StartProcessCommand startProcessCommand = new StartProcessCommand(HUMAN_TASK_PROCESS_ID,
                new HashMap<String, Object>(), outIdentifier);
ExecutionResults result = sc.execute(startProcessCommand);
assertNotNull(result);
Long processInstanceId = (Long) result.getValue(outIdentifier); // the processInstanceId is null

and as I logged the result, actually there are no values at all.