Bug 1255566

Description of problem:

When trying to start a process using using the REST API and an exception is thrown, the response is a XML even if we try to request JSON.


Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Create a simple process that has a script task that throws an exception. Here is an example of a script task content:

throw new Exception();

2. Build and deploy the project with the script task
3. Try to start it using the REST API and request for JSON:

$ curl -X POST -u 'jesuino:redhat2014!' -H 'Accept: application/json' http://localhost:8080/business-central/rest/runtime/org.kie.example:project1:1.0/process/project1.exp_proc/start

Actual results:

The response is returned as XML:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<exception>
    <status>FAILURE</status>
    <url>http://localhost:8080/business-central/rest/runtime/org.kie.example:project1:1.0/process/project1.exp_proc/start</url>
    <message>WorkflowRuntimeException thrown with message '[project1.exp_proc:57 - :2] -- null'</message>
    <stackTrace>org.kie.remote.services.rest.exception.KieRemoteRestOperationException: [project1.exp_proc:57 - :2] -- null
	at org.kie.remote.services.rest.exception.KieRemoteRestOperationException.internalS(...)
	... 76 more
</stackTrace>
</exception>

Expected results:

Since JSON was requested, it should return JSON instead XML.

Additional info:

This happens because the DescriptiveExceptionHandler returns a String representation of the error:

https://github.com/droolsjbpm/droolsjbpm-integration/blob/master/kie-remote/kie-remote-services/src/main/java/org/kie/remote/services/rest/exception/DescriptiveExceptionHandler.java#L101

https://github.com/droolsjbpm/droolsjbpm-integration/blob/master/kie-remote/kie-remote-jaxb/src/main/java/org/kie/services/client/serialization/jaxb/impl/JaxbRestRequestException.java#L80-L85


This could be solved by setting the JaxbRestRequestException itself as the response entity instead returning the String.