如何将新应用程序与旧的现有应用程序集成

I have created one application in NetBeans. I think that application is enough(contains basic functionality). Now I would like to create another application that is question answer forum and want to integrate those forum with my old application. So how my old applications session values will accessed in my new application. And how can i access my old applications other parameter(classes like for login, objects etc) will accessed from my new application.I have created one application in NetBeans. I t