Collectors in Java

Belongs to java.util.Stream.Collectors
Helps in Accumulating or copying the data from Stream Object to Collection Object . (Collections framework as in List ,Set)

Summarizing or performing operatiosn based on some criteria.

List<Integer> l=new ArrayList();
l.add(10);
l.add(20);
l.add(30);
l.add(40);

    List l2=l.stream().map(i->i*i).collect(Collectors.toList());