The iterator() method of ArrayBlockingQueue class is used to returns an iterator of the same elements as this queue in a proper sequence. The elements returned from this method contains elements in order from first(head) to last(tail). The returned iterator is weakly consistent.
Syntax:
public Iterator iterator()
Return Value: The method returns the iterator having same elements as present in ArrayBlockingQueue in proper sequence.
Below programs illustrates iterator() method of ArrayBlockingQueue class:
Program 1:
// Program Demonstrate how to apply iterator() method// of ArrayBlockingQueue Class.  import java.util.concurrent.ArrayBlockingQueue;import java.util.*;  public class GFG {      public static void main(String[] args)    {        // Define capacity of ArrayBlockingQueue        int capacity = 5;          // Create object of ArrayBlockingQueue        ArrayBlockingQueue<Integer> queue = new                 ArrayBlockingQueue<Integer>(capacity);          // Add 5 elements to ArrayBlockingQueue        queue.offer(423);        queue.offer(422);        queue.offer(421);        queue.offer(420);        queue.offer(424);          // Print queue        System.out.println("Queue is " + queue);          // Call iterator() method and Create an iterator        Iterator iteratorValues = queue.iterator();          // Print elements of iterator        System.out.println("\nThe iterator values:");        while (iteratorValues.hasNext()) {            System.out.println(iteratorValues.next());        }    }} |
Output:
Queue is [423, 422, 421, 420, 424] The iterator values: 423 422 421 420 424
Program 2:
// Program Demonstrate how to apply iterator() method// of ArrayBlockingQueue Class.  import java.util.concurrent.ArrayBlockingQueue;import java.util.*;  public class GFG {      public static void main(String[] args)    {        // Define capacity of ArrayBlockingQueue        int capacity = 5;          // Create object of ArrayBlockingQueue        ArrayBlockingQueue<String> queue = new                   ArrayBlockingQueue<String>(capacity);          // Add 5 elements to ArrayBlockingQueue        queue.offer("User");        queue.offer("Employee");        queue.offer("Manager");        queue.offer("Analyst");        queue.offer("HR");          // Print queue        System.out.println("Queue is " + queue);          // Call iterator() method and Create an iterator        Iterator iteratorValues = queue.iterator();          // Print elements of iterator        System.out.println("\nThe iterator values:");        while (iteratorValues.hasNext()) {            System.out.println(iteratorValues.next());        }    }} |
Output:
Queue is [User, Employee, Manager, Analyst, HR] The iterator values: User Employee Manager Analyst HR
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ArrayBlockingQueue.html#iterator
