Queue<Integer> q = new Queue<Integer>();

public class MyQueue<T extends Tree> implements Queue<T> {
   public T element() {
     ... your code to return an element goes here ...
   }

   public boolean offer(T element) {
     ... your code to accept a submission offer goes here ...
   }

   ... etc ...
}

new Queue<Tree>() {
   public Tree element() {
     ...
   };

   public boolean offer(Tree element) {
     ...
   };
   ...
};

Queue<Integer> q = new LinkedList<Integer>();

Queue<Integer> q = new ArrayDeque<Integer>();

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

qe.add("b");
qe.add("a");
qe.add("c");

Queue linkedList = new LinkedList();

java.util.Queue<String> queue = new LinkedList<>();
queue.offer("Hello");
queue.offer("StackOverFlow");
queue.offer("User");

System.out.println(queue.peek());

while (queue.size() > 0){
    System.out.println(queue.remove() + " ");
}
//Since Queue is empty now so this will return NULL
System.out.println(queue.peek());

Hello
Hello
StackOverFlow
User
null

Queue<Integer> Q = new LinkedList<>();

Queue<Integer> Q = new ArrayDeque<>();

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

public class QueueExample {

 public static void main (String[] args) {
  Queue que = new LinkedList();
  que.add("first");
  que.offer("second");
  que.offer("third");
  System.out.println("Queue Print:: " + que);

  String head = que.element();
  System.out.println("Head element:: " + head);

  String element1 = que.poll();
  System.out.println("Removed Element:: " + element1);

  System.out.println("Queue Print after poll:: " + que);
  String element2 = que.remove();
  System.out.println("Removed Element:: " + element2);

  System.out.println("Queue Print after remove:: " + que);
 }
}

Queue<Integer> Q = new LinkedList<Integer>();