JBoss Community

If you are not going to use jBPM5 runtime maybe you can take a look at this project: https://github.com/eclipse/bpmn2

It contains all the model classes neded for create bpmn2 processes. These are the classes used by jbpm-web-designer to transform from json to bpmn2 and viceversa (similar to what you are trying to do). The main classes in chage of that are:

https://github.com/tsurdilo/process-designer/blob/master/src/main/java/com/intalio/bpmn2/impl/Bpmn2JsonMarshaller.java and https://github.com/tsurdilo/process-designer/blob/master/src/main/java/com/intalio/bpmn2/impl/Bpmn2JsonUnmarshaller.java

https://github.com/tsurdilo/process-designer/blob/master/src/main/java/com/intalio/bpmn2/impl/Bpmn2JsonUnmarshaller.java