I am working Java EE application. Requirements are very less as of now, only one view. But in future requirement may add and I have to add some more views to it. I don't want to use any framework. Need to know which pattern should I follow so that minimal changes are required to add new view. Is it ok to have separate servlet for every different action or should I follow front controller so that I can plug in action and view. Major tech stack which I will be using is AJAX, webservice, jsp,servlet (obviously) thats it Also I have a requirement to create a service which I want to load on server start up or ASAP.
You can stick to JEE6 stack itself, where you can use JSF 2.0 for developing AJAX based application. JSF 2.0 have front controller anyway as part of its architecture. So you can build an application without any additional frameworks.