The Queue interface in the Java Collections Framework represents a collection of elements that supports insertion and removal operations. It follows the first-in, first-out (FIFO) principle, where the element that is added first is also the first one to be removed.

One of the implementations of the Queue interface is the LinkedList class. It provides efficient operations for adding elements to the end of the queue (enqueue or add) and removing elements from the front of the queue (dequeue or poll).

Here's an example of using the Queue interface with the LinkedList class:

1// Create a Queue using LinkedList
2Queue<String> queue = new LinkedList<>();
3
4// Enqueue elements
5queue.add("John");
6queue.add("Alice");
7queue.add("Bob");
8
9// Dequeue elements
10String firstElement = queue.poll();
11String secondElement = queue.poll();
12
13// Print the dequeued elements
14class Main {
15  public static void main(String[] args) {
16    System.out.println(firstElement); // Output: John
17    System.out.println(secondElement); // Output: Alice
18  }
19}

In the above code, we create a Queue using the LinkedList class and add elements (John, Alice, and Bob) to the queue. We then dequeue the elements using the poll method and print the dequeued elements (John and Alice).

The Queue interface and the LinkedList class are commonly used in various scenarios, such as task scheduling, message passing, and event handling, where the order of elements is important.

xxxxxxxxxx

class Main {

  public static void main(String[] args) {

    // Create a Queue using LinkedList

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

​

    // Enqueue elements

    queue.add("John");

    queue.add("Alice");

    queue.add("Bob");

​

    // Dequeue elements

    String firstElement = queue.poll();

    String secondElement = queue.poll();

​

    // Print the dequeued elements

    System.out.println(firstElement); // Output: John

    System.out.println(secondElement); // Output: Alice

  }

}