Can contributing to openSource (as java developer) help me get a great job?

Question

what are few java based projects..

Answer 1

Contributing to Open-source is the best way to show a company your capabilities to be a professional developer, because they know that you as a contributor, you have experience in building a professional software, you understand the proper work flow, quality control and code committing and patch submitting.
These are the most precious job requirements a developer must processes in order to build a great software.

If you could show Google/Facebook, a lot of critical commits into Java Open-source codes like Android, Eclipse, Hadoop. you are going to make them recruit you right away..