Common elements in two lists

Question

I have two ArrayList objects with three integers each. I want to find a way to return the common elements of the two lists. Has anybody an idea how I can achiev

Answer 1

    // Create two collections:
    LinkedList listA =  new LinkedList();
    ArrayList listB =  new ArrayList();

    // Add some elements to listA:
    listA.add("A");
    listA.add("B");
    listA.add("C");
    listA.add("D");

    // Add some elements to listB:
    listB.add("A");
    listB.add("B");
    listB.add("C");

    // use 

    List common = new ArrayList(listA);
    // use common.retainAll

    common.retainAll(listB);

    System.out.println("The common collection is : " + common);