Adding user authentication in java web app

I need to authenticate the users who visit my java based 开发者_StackOverflowweb app (Servlets and JSP) using different social media like facebook, twitter, google and yahoo.

Is there any open source library which solves this problem? Instead of working on different API's an open source java library would be helpful.

The guys from SpringSource have a library doing what you ask for, called Spring Social. The linked blog article explains what it does with some nice examples. But the project is still in beta (even though the quality of their deliverables has always been rock solid).

Take a look at openid4java.

This library allows you to OpenID-enable your Java webapp.

You can use Open ID with openid4java.