Suggest a project for `Software Engineering` which uses Java ?

i have around 4 months to complete the project..

About how many hours are you expected to put into it?

Try to use Rational Rose for java using 'Software Engineering' concepts.
You can search for different projects on google & whatever you expecting which will complete within your time period choose that one.
There are so many projects basically web based in java.
e.g. Online reservation for bus, railway or airplane, Hotel management, Vechicle Manifacturing System, Maintenace of Vechicle System, Banking, etc.

if u r in a college and you have access to Rational Rose software u can do a proj in that... else u can pick up java and do some small projects like a chat application or a text editor...

I would write an application for the new "google phones" which should be out soon. You can check out the API and tools at http://code.google.com/android/.

do project on video conferencing using RMI.