How to randomize the given number without dublication in Java?

Question

How to randomize the given number without dublication?

I need the algorithm of the randomizing the entered numbers with no repetition.
For example: select 20 numbers from 1 to 100 without duplication.

Answer 1

You can use set for storing unique values only.
And you can do just like this,

Random rand =new Random();
LinkedHashSet set =new LinkedHashSet();

while (set.size() != 20)
{
set.add(rand.nextInt(100) + 1);
}

for (Integer s: set)
System.out.println(s);
}