Shibasis,
https://community.jboss.org/people/roxy1987/blog/2013/01/22/jbpm5-web-application-example this is an example of web application.Its a running example configured to run with WAS and DB2. I created this in my initial days of exploring jBPM5. A lot has been changed by now but atleast this will get you started. Any questions let me know..
Regards.