extracting 5 random elements from an ArrayList

[ankit1801]

i have an arraylist of 30 elements. i need to randomly extract any 5 elements from the list. i am using the Random function but i am not getting 5 different elements, the elements are getting repeated. how to get unique entries from the arraylist? please help :(

[sunde887]

Use a random object and use nextInt for the range 0-29, use that to index into the array list, then keep track if numbers previously generated and ignore the random number if it's been seen already.

[Junky]

If allowed the simplest way is to use Collections.shuffle and poll the first 5 objects.

[pbrockway2]

Or shuffle() the list and take the first 5 elements. (But note the shuffle is "in place" - ie it will alter the ordering of the list being shuffled - so you might want to copy the list first.)