LinkedBlockingQueue clear() method in Java

The clear() method of LinkedBlockingQueue removes all of the elements from this queue. After applying this method the queue will become empty.

Syntax:

public void clear()

Below programs illustrates clear() method of LinkedBlockingQueue class:

Program 1:

// Java Program Demonstrate clear()
// method of LinkedBlockingQueue

import java.util.concurrent.LinkedBlockingQueue;

public class GFG {

    public static void main(String[] args)
    {
        // define capacity of LinkedBlockingQueue
        int capacityOfQueue = 50;

        // create object of LinkedBlockingQueue
        LinkedBlockingQueue<Integer> linkedQueue
            = new LinkedBlockingQueue<Integer>(capacityOfQueue);

        // Add element to LinkedBlockingQueue
        linkedQueue.add(2300);
        linkedQueue.add(1322);
        linkedQueue.add(8945);
        linkedQueue.add(6512);

        // print queue
        System.out.println("LinkedBlockingQueue before using"
                           + " clear() : " + linkedQueue);

        // Apply clear() method
        linkedQueue.clear();

        // print queue
        System.out.println();
        System.out.println("LinkedBlockingQueue after using"
                           + " clear() method : " + linkedQueue);
    }
}

Output:

LinkedBlockingQueue before using clear() : [2300, 1322, 8945, 6512]

LinkedBlockingQueue after using clear() method : []

Program 2:

// Java Program Demonstrate clear()
// method of LinkedBlockingQueue

import java.util.concurrent.LinkedBlockingQueue;

public class GFG {

    public static void main(String[] args)
    {
        // define capacity of LinkedBlockingQueue
        int capacityOfQueue = 50;

        // create object of LinkedBlockingQueue
        LinkedBlockingQueue<String> names
            = new LinkedBlockingQueue<String>(capacityOfQueue);

        // Add element to ArrayBlockingQueue
        names.add("Shubham");
        names.add("Siddhant");
        names.add("Mahafuj");
        names.add("Arka");
        names.add("Raunak");

        // print queue
        System.out.println("LinkedBlockingQueue before using"
                           + " clear() : " + names);

        // Apply clear() method
        names.clear();

        // print queue
        System.out.println();
        System.out.println("LinkedBlockingQueue after using"
                           + " clear() method : " + names);
    }
}

Output:

LinkedBlockingQueue before using clear() : [Shubham, Siddhant, Mahafuj, Arka, Raunak]

LinkedBlockingQueue after using clear() method : []

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/LinkedBlockingQueue.html#clear–