Vim, Java: Open class under cursor and go to method

Vim can open a file under cursor using gf. For example, if I have the following under my cursor:

SensorManagementActivity.java

Hitting gf will open SensorManagementActivity.java.

The problem is that in Java, the references lack the java suffix, and often appear as SomeClass, SomeClass() or SomeClass.method().

• How do I open SomeClass.java and jump to someMethod() when the cursor is on SomeClass.someMethod() in another file?
• Is there a way to open a new file without saving the current one, and going back to the current one without losing changes?

The 'suffixesadd' option allows gf to handle Java file extensions; it is already set by the java filetype that ships with Vim, like this:

:setlocal suffixesadd=.java

To jump to methods, Vim can use a tags file that must be (re-)generated first (there are plugins that can automate that). For Java, you can use the exuberant ctags tool.

:! ctags -R

For more information and alternatives, read :help ctags. Use the :tag command or the Ctrl-] shortcut to jump.

You can jump to a split window via Ctrl-W ]. To be able to leave a modified file and return back to it later, :set hidden in your ~/.vimrc.

^{PS: Though here they're kind of related, it's best to avoid asking multiple questions at Stack Overflow}