ArrayBlockingQueue remove() method in Java

Last Updated : 26 Nov, 2018

ArrayBlockingQueue is bounded, blocking queue that stores the elements internally backed by an array.

ArrayBlockingQueue class is a member of the Java Collections Framework.
Bounded means it will have a fixed size, you can not store number the elements more than the capacity of the queue.
The queue also follows FIFO (first-in-first-out) rule for storing and removing elements from the queue.
If you try to put an element into a full queue or to take an element from an empty queue then the queue will block you.

The remove(Object o) method removes a single instance of the specified element from this queue, if it is present. We can say that method removes an element e such that o.equals(e) if this queue contains one or more such elements. Remove() method returns true if this queue contained the specified element which we want to remove. Syntax:

public boolean remove(Object o)

Parameter: o - element to be removed from this queue, if present. Returns: returns true if this queue contained the specified element which we want to remove. Below program illustrate remove(Object o) method of ArrayBlockingQueue. Example 1

Java

// Java Program Demonstrate remove(Object o)
// method of ArrayBlockingQueue.
import java.util.concurrent.ArrayBlockingQueue;

public class GFG {

    public static void main(String[] args) throws InterruptedException
    {
        // define capacity of ArrayBlockingQueue
        int capacity = 5;

        // create object of ArrayBlockingQueue
        ArrayBlockingQueue<Integer> queue
            = new ArrayBlockingQueue<Integer>(capacity);

        // Add elements to ArrayBlockingQueue using put method
        queue.put(223);
        queue.put(546);
        queue.put(986);

        // print Queue
        System.out.println("queue contains " + queue);

        // remove 223
        boolean response = queue.remove(223);
        // print Queue
        System.out.println("Removal of 223 :" + response);

        // print Queue
        System.out.println("queue contains " + queue);

        // remove 546
        response = queue.remove(546);
        // print Queue
        System.out.println("Removal of 546 :" + response);

        // print Queue
        System.out.println("queue contains " + queue);

        // remove 734 which is not present
        response = queue.remove(734);
        // print Queue
        System.out.println("Removal of 734 :" + response);

        // print Queue
        System.out.println("queue contains " + queue);
    }
}

Output :
queue contains [223, 546, 986]
Removal of 223 :true
queue contains [546, 986]
Removal of 546 :true
queue contains [986]
Removal of 734 :false
queue contains [986]

Example 2

Java

// Java Program Demonstrate remove(Object o)
// method of ArrayBlockingQueue.

import java.util.concurrent.ArrayBlockingQueue;

public class GFG {

    public static void main(String[] args) throws InterruptedException
    {
        // define capacity of ArrayBlockingQueue
        int capacity = 5;

        // create object of ArrayBlockingQueue
        ArrayBlockingQueue<String> queue
            = new ArrayBlockingQueue<String>(capacity);

        // Add elements to ArrayBlockingQueue using put method
        queue.put("StarWars");
        queue.put("SuperMan");
        queue.put("Flash");
        queue.put("BatMan");
        queue.put("Avengers");

        // print Queue
        System.out.println("queue contains " + queue);

        // remove StarWars
        boolean response = queue.remove("StarWars");
        // print Queue
        System.out.println("Removal of StarWars :" + response);

        // print Queue
        System.out.println("queue contains " + queue);

        // remove Hulk
        response = queue.remove("Hulk");
        // print Queue
        System.out.println("Removal of Hulk :" + response);

        // print Queue
        System.out.println("queue contains " + queue);
    }
}

Output :
queue contains [StarWars, SuperMan, Flash, BatMan, Avengers]
Removal of StarWars :true
queue contains [SuperMan, Flash, BatMan, Avengers]
Removal of Hulk :false
queue contains [SuperMan, Flash, BatMan, Avengers]

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ArrayBlockingQueue.html#remove(java.lang.Object)