Queue Implementation in Java with Examples

You can implement Queue Data Structure (based on FIFO algorithm) in Java using the Queue interface or the LinkedList class.

Let us take a look at queue implementation using both of them:

1. Implementing Queue using LinkedList

package org.code2care.collections;

import java.util.LinkedList;

/**
 * Implementing Queue in Java using
 * LinkedList
 *
 * Author: Code2care.org
 * Date: 2nd May 2023
 * Version: v1.0
 *
 */
public class JavaQueueLinkedListExample {
    public static void main(String[] args) {

        LinkedList<String> queue = new LinkedList<>();

        //Adding elements to queue
        queue.add("USA");
        queue.add("Japan");
        queue.add("China");
        queue.add("Canada");
        queue.add("India");


        //Printing the elements of the Queue
        for (String element : queue) {
            System.out.println(element);
        }
    }
}

USA
Japan
China
Canada
India

2. Implementing Queue using Queue Interface

package org.code2care.java.sorting.algo;

import java.util.LinkedList;
import java.util.Queue;

public class QueueExampleUsingQueueInterface {
    
    public static void main(String[] args) {


        Queue<String> queue = new LinkedList<>();

        queue.add("China");
        queue.add("Japan");
        queue.add("USA");
        queue.add("Australia");

        for (String element : queue) {
            System.out.println(element);
        }
    }
}

China
Japan
USA
Australia

Which one to choose?

If you need a simple Queue implementation with basic functionality, make use of the Queue interface. If you need more advanced functions such as adding/removing elements from specific positions make use of the LinkedList implementation.