The iterator() method of DelayQueue is used to return an iterator over all the elements in the DelayQueue. These elements can be expired or unexpired.
Syntax:
public Iterator iterator ()
Parameters: This method does not accept any parameter.
Returns: This method returns an iterator over elements in this delayqueue.
Below program to illustrate DelayQueue iterator() in Java:
Example:
Java
// Java Program Demonstrate DelayQueue iterator() methodimport java.util.concurrent.*;import java.util.*;// The DelayObject for DelayQueue// It must implement Delayed and// its getDelay() and compareTo() methodclass DelayObject implements Delayed { private String name; private long time; // Constructor of DelayObject public DelayObject(String name, long delayTime) { this.name = name; this.time = System.currentTimeMillis() + delayTime; } // Implementing getDelay() method of Delayed @Override public long getDelay(TimeUnit unit) { long diff = time - System.currentTimeMillis(); return unit.convert(diff, TimeUnit.MILLISECONDS); } // Implementing compareTo() method of Delayed @Override public int compareTo(Delayed obj) { if (this.time < ((DelayObject)obj).time) { return -1; } if (this.time > ((DelayObject)obj).time) { return 1; } return 0; } // Implementing toString() method of Delayed @Override public String toString() { return "\n{" + " " + name + ", time=" + time + "}"; }}// Driver Classpublic class GFG { public static void main(String[] args) throws InterruptedException { // create object of DelayQueue // using DelayQueue() constructor BlockingQueue<DelayObject> DQ = new DelayQueue<DelayObject>(); // Add numbers to end of DelayQueue // using add() method DQ.add(new DelayObject("A", 1)); DQ.add(new DelayObject("B", 2)); DQ.add(new DelayObject("C", 3)); DQ.add(new DelayObject("D", 4)); // Creating an iterator Iterator val = DQ.iterator(); // print the value after iterating DelayQueue System.out.println("The iterator values are: "); while (val.hasNext()) { System.out.println(val.next()); } }} |
Output:
The iterator values are:
{ A, time=1545818784540}
{ B, time=1545818784541}
{ C, time=1545818784542}
{ D, time=1545818784543}
