Add Java support to Eclipse
You should be able to install the JAVA components, using Help > Install New Software
.
In the list of components, there should be Programming Languages > Eclipse Java Development Tools
.
Here's a screenshot :
(source: pascal-martin.fr)
On my version of eclipse:
Help menu->install new software
Choose the download page for your version of eclipse
There is a category "programming language" which should have Java.
Because it is so trivial to have multiple Eclipse instances, I do just that to seperate php and java environments. This reduces the plugins loaded and you can somewhat keep Eclipse lean. Of course the choice is totally yours.