Question

I want to shuffle an array in java but not to change the original list, only shuffle the temporary list.

I wrote something like this.

    ArrayList<TristateCheckBox> tempList = buttons; 
Collections.shuffle(tempList);  

But this not shuffles only tempList also changes the buttons list.

Answer 1

You need to take a copy of the List, not just a copy of the reference to the list.

List<TristateCheckBox> tempList = new ArrayList<TristateCheckBox>(buttons); 
Collections.shuffle(tempList);