On www.vim.org there is a viml only java parser. But AFAIK it is no longer developped. It may work well for simple Java projects.
Most IDES (Netbeans, Eclipse, IDEA) implement Vim like modes today. In the Eclipse case you have to pay some $ (viplugin).
IDES usually also implement
Eg Eclipse implements "create method from usage" quickfix like stuff which might be very helpful.
As alternative there is a headless Eclipse implementation which can be used to provide some features for Vim even refactorings etc. Its called eclim. However naturally you'll have some small overhead.
Thus the best option could be start both and use whatever app is best suited for your current task.