did you grab the rpm/tarball of Java off of Sun's site?
If you did, verify that java is in your path by going to a terminal and typing:
and you should get output teling you its there or not. If its not there, add to your path (~/.bash_profile) /usr/java/jre1.3.1_04/bin or whatever your path is to java's binary. That should be all thats necessary to get java implemented correctly.
As for a wine version of java -- that probably will give ou grief. I would stick with trying ot use a native java, rather than emulating it.