Deployment is on Alfresco Activiti Enterprise 1.5.3, tried the same with Activiti Process Services 1.6 too with same problem.
I was reading in the admin guide and community regarding bean injections into service task through expressions and JavaDelegate. But in my case it is a TaskListener... I am not quite sure how to go about it.
where Dirla Vasile mentions: "in order to have properly injected the services you should use expression or delegateExpression. if you really need to use "class" for setting the listener, then you have to use Expression for the userService and evaluate it at runtime in the notify method."
I was calling the TaskListener by mentioning the class name and not through delegateExpression. Once I removed the class name and used delegateExpression alone then the Autowired Objects were initialized properly.