find java file

I suppose this question is a jdee question and not a emacs question.

How can i find quickly a java file in jdee environment in emacs? For 
example, i want to find the foo.java file. My wish is to, simple write 
foo.java, and automatically, the jdee goes to the right dir and opens 
the file. If not possible, i want to know in what directory is the 
foo.java file.

My application is inside a project. What i'm saying is that i have a 
prj.el configured in my application.

Thanks
Pedro