Creating random numbers with no duplicates

Question

In this case, the MAX is only 5, so I could check the duplicates one by one, but how could I do this in a simpler way? For example, what if the MAX has a value of 20? Thanks

Answer 1

This would be a lot simpler in java-8:

Stream.generate(new Random()::ints)
            .distinct()
            .limit(16) // whatever limit you might need
            .toArray(Integer[]::new);