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

In case you want to do it yourself..

List commons = new ArrayList();

for (Integer igr : group1) {
    if (group2.contains(igr)) {
        commons.add(igr);
    }
}

System.out.println("Common elements are :: -");
for (Integer igr : commons) {
    System.out.println(" "+igr);
}