Report in java!!! What kind of a report do u want to prepare. A soft report, as in a software that creates report. A hard report, i.e. a paper report on java.
If you are doing a paper report, i'd suggest that you start with the history of java, what was it used for initially, why did they call it java. Then move on to some serious aspects like its utilities. Write about the various "things" that java could do like networking, cross platform ability. Write about
applets,
servlets, applications,
jsp (blah, blah....). Then show its use in mobiles, wap etc and conclude it with java's future.
I hope ur doing the hard report...