how to create read only collection implementations

Collections , a utility class in Collections framework , provided six factory methods , for each
Collection, List,
 Map, SortedMap,
Set, ,SortedSet.
(remember ther is no Queue)


lets check with the example for set



public class Child {

public static void main(String[] args){

Set<Integer> s = new HashSet<Integer>();

s.add(1);
s.add(2);
s.add(3);
s.add(4);
s.add(5);

System.out.println(s);

Set s1 = Collections.unmodifiableSet(s);

s1.add(6);


}

}


if we try to run this , then we will get below exception

java.lang.UnsupportedOperationException