LinkedBlockingDeque retainAll() method in Java with Examples
Last Updated : 19 Mar, 2019
The
retainAll() method of
LinkedBlockingDeque is an in-built function is Java which is used to remove from this deque all of its elements that are contained in the specified collection. That means, all the common elements these two collections are removed from this deque.
Syntax: public boolean retainAll(Collection c)
Parameters: This method takes collection
c as a parameter containing elements to be removed from this list.
Return Value: This method returns true if this deque changed as a result of the call.
Exceptions: This method throws
NULL Pointer Exception if the specified collection is Null. Below program illustrates the retainAll() function of LinkedBlockingDeque class:
Example 1: Java // Java Program Demonstrate retainAll() // method of LinkedBlockingDeque import java.util.concurrent.LinkedBlockingDeque; import java.util.*; public class GFG { public static void main(String[] args) throws IllegalStateException { // Create object of LinkedBlockingDeque LinkedBlockingDeque<Integer> LBD = new LinkedBlockingDeque<Integer>(); // Add numbers to end of LinkedBlockingDeque LBD.add(11); LBD.add(22); LBD.add(33); LBD.add(44); // print deque System.out.println("Linked Blocking Deque: " + LBD); // Create object of ArrayList collection ArrayList<Integer> ArrLis = new ArrayList<Integer>(); // Add number to ArrayList ArrLis.add(55); ArrLis.add(11); ArrLis.add(23); ArrLis.add(22); // Print ArrayList System.out.println("ArrayList to be retained: " + ArrLis); // Function retainAll() retains // all the common elements from deque LBD.retainAll(ArrLis); // Print deque System.out.println("Retained Linked Blocking Deque: " + LBD); } } Output: Linked Blocking Deque: [11, 22, 33, 44] ArrayList to be retained: [55, 11, 23, 22] Retained Linked Blocking Deque: [11, 22]
Example 2: Java // Java Program Demonstrate retainAll() // method of LinkedBlockingDeque import java.util.concurrent.LinkedBlockingDeque; import java.util.*; public class GFG { public static void main(String[] args) throws IllegalStateException { // Create object of LinkedBlockingDeque LinkedBlockingDeque<String> LBD = new LinkedBlockingDeque<String>(); // Add numbers to end of LinkedBlockingDeque LBD.add("geeks"); LBD.add("Geeks"); LBD.add("gfg"); LBD.add("Gfg"); // Print deque System.out.println("Linked Blocking Deque: " + LBD); // Create object of ArrayList collection ArrayList<String> ArrLis = new ArrayList<String>(); // Add elements to ArrayList ArrLis.add("GeeksforGeeks"); ArrLis.add("Geeks"); ArrLis.add("gfg"); ArrLis.add("Gfg"); // Print ArrayList System.out.println("ArrayList to be retained: " + ArrLis); // Function retainAll() retains // all the common elements from deque LBD.retainAll(ArrLis); // Print deque System.out.println("Retained Linked Blocking Deque: " + LBD); } } Output: Linked Blocking Deque: [geeks, Geeks, gfg, Gfg] ArrayList to be retained: [GeeksforGeeks, Geeks, gfg, Gfg] Retained Linked Blocking Deque: [Geeks, gfg, Gfg]
Reference: https://docs.oracle.com/javase/9/docs/api/java/util/concurrent/LinkedBlockingDeque.html#retainAll-java.util.Collection-