My apologies, the documentation and code for the Remote API was not as finished in 6.0.1.Final as it should have been.
Can you explain what the problems were that you encountered with the REST Remote java RuntimeEngine Factory? Of the 3 approaches that you describe, I probably tested that one the most and it's probably also the most straightforward.
Here are some notes that I have taken while learning how to make REST calls;
You must have the process deployed
You need to get the deploymentId and processDefId
for the HR example these are deploymentId is "org.jbpm:HR:1.0" and processDefId is "hiring"
I use SOUPUI to test the services and these are my settings;
I use basic authentication which is admin/admin, and with SOUPUI there is a button to select Authenticate pre-emptively that I had to select for it to work.
It also requires an accept header set to application/json.
One thing I have not been able to figure out is how to get a listing of processDefIds using the Rest services.
It's not possible to get a listing of processDefIds using the REST or JMS services.
For the REST Interface, I have it working, it was working all the time, but I was getting a timeout from my client, was not related to the rest interface.
How can we fully integrate with the REST service if we can't get a list of the processDefIds or the processDefId for a certain process. I would think you need to get this Id to be able to automate the process. For example if I create a list of processes on a website and want to create an execute button, I don't think that is possible with the current REST interface unless I am missing something.