vibhas bhingarde wrote: . . . i have no idea how would i do it . . .
Nor have I.
But if you could work out how to do it without the GUI, that would be a big step. If you have a class, eg Object, and write a dot, how are you going to get the list of members of that class? If you can do that, getting it onto a GUI is relatively easy. You are going to have to go back to a paper and pencil (and a large eraser) and work it out from there. Also read through the Java™ Tutorials and the standard API; I can think of something in the java.lang package which might give you a hint.
You should also consider how many marks you will get for this enhancement, and whether the work involved will be rewarded with many marks, or whether you should consider some other part of the assignment. If, for example, you have to write a description of the work, and you have nothing written yet, you might earn more marks by writing the report and omitting the dot functionality.