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

List listA = new ArrayList<>();
    listA.add(1);
    listA.add(5);
    listA.add(3);
    listA.add(4);   

List listB = new ArrayList<>();
    listB.add(1);
    listB.add(5);
    listB.add(6);
    listB.add(7);
System.out.println(listA.stream().filter(listB::contains).collect(Collectors.toList()));


Java 1.8 Stream API Solutions

Output [1, 5]