how to generate 4 set of questions

[ravi.virgoo@gmail.com]

I have a question bank(qb) .Form this qb i need to qenerate 4 sets of questions witout duplcates.In question bank questions again are arranged as 8 units and in 8 units i have 3 different formats i.e (simple questions,difficult questions,mediumquestions), before generating sets user will give input location of qb and level of quest(simple,diff,mediu).

[PhHein]

How is that related to Swing? Do you have a question?

[ravi.virgoo@gmail.com]

This was application already developed using swings.
But it was generating 4 sets of questions with some duplicates.

[ravi.virgoo@gmail.com]

Now i need to generate 4 sets of quest with out duplicates

[PhHein]

And do you have a question? What doesn't work? Complier errors? Runtime Exceptions? Stack trace?

[ravi.virgoo@gmail.com]

That application was working perfectly but in some sets same questions are repeating.
so, i want to generate 4sets of questions with out any repetitions .

[PhHein]

As you refuse to answer my questions, I can only give you a vague hint.

Implement a Set. You cannot have duplicates in a java.util.Set

[ravi.virgoo@gmail.com]

sir, in my applic they already used java.util.List.
I am not clear with old application so i planned to write a new class for generating 4sets,

[PhHein]

Ok, that's fine. Do it.

[zweibieren]

Somehow your code will have to
keep track of what questions have been selected so far.
You then have two possible approaches:

1. Select the next question from those that have not been selected.
2. Select a random question and reject it if it has already been selected.

Your choice will depend on how many questions there are altogether.
If there are under a thousand questions, any approach will do.
If there are many questions, approach a may be impractical.