Which of the java web development framework is best for startup project?
It depends on what your project is about and what are you building.
Check out Play - I'm not a Java dev, but it should be fairly popular: http://www.playframework.com/
What about the wicket framework, is it ok?
Haven't heard of it unfortunately so I can't comment on it.
Generally speaking, the number of followers/contributors at Github is a pretty good sign of the overall activity of certain framework. Play has way higher numbers - you can see that here:
https://github.com/playframework/playframework https://github.com/apache/wicket