/**
* Method to retain a Collection of elements (and remove all others).
*
* @param c The collection to retain
* @return Whether they were retained successfully.
*/
public synchronized boolean retainAll(java.util.Collection c) {
boolean success = delegate.retainAll(c);
if (success) {
makeDirty();
if (ownerOP != null && !ownerOP.getExecutionContext().getTransaction().isActive()) {
ownerOP.getExecutionContext().processNontransactionalUpdate();
}
}
return success;
}
public void methodsOfPQ() {
PriorityQueue<Integer> pq = new PriorityQueue<Integer>(); // Default Constructor:
// Queue<Integer> pq = new PriorityQueue<Integer>();
pq.add(10);
pq.add(30);
pq.add(50);
pq.add(40);
pq.add(20);
System.out.println(pq); // [10, 20, 50, 40, 30]
pq.offer(75); // add element randomly anywhere
System.out.println(pq); // [10, 20, 50, 40, 30, 75]
System.out.println(pq.peek()); // 10 | return head of queue and don't touch pq
System.out.println(pq); // [10, 20, 50, 40, 30, 75]
System.out.println(pq.poll()); // 10 | return head and also removes head from pq
System.out.println(pq); // [20, 50, 40, 30, 75]
System.out.println(pq.element()); // 20 | same as peek but throw exception if pq is empty
System.out.println(pq); // [20, 50, 40, 30, 75]
pq.remove(); // 20 | same as poll but throw exception when queue is empty
System.out.println(pq); // [50, 40, 30, 75]
List<Integer> ls = new ArrayList<Integer>();
ls.add(1000);
ls.add(2000);
pq.addAll(ls);
System.out.println(pq); // [30, 40, 50, 75, 1000, 2000]
pq.removeAll(ls);
System.out.println(pq); // [30, 40, 50, 75]
ls.clear(); // empty ls
ls.add(101);
ls.add(102);
pq.addAll(ls);
pq.retainAll(ls); // all element will be removed except ls
System.out.println(pq); // [101, 102]
System.out.println(pq.containsAll(ls)); // true
System.out.println("********************************************");
// Queue<String> q=new PriorityQueue<String>();
}
