Implement Queue by Two Stack

Java

public class MyQueue {
    private Stack<Integer> stack1;
    private Stack<Integer> stack2;
    
    public MyQueue() {
        // do intialization if necessary
        stack1 = new Stack<Integer>();
        stack2 = new Stack<Integer>();
    }

    /*
     * @param element: An integer
     * @return: nothing
     */
    public void push(int element) {
        stack1.push(element);
    }

    /*
     * @return: An integer
     */
     
     private void stack1Tostack2(){
         while(!stack1.empty()){
             stack2.push(stack1.peek());
             stack1.pop();
         }
     }
     
    public int pop() {
        // write your code here
        if(stack2.empty()){
            stack1Tostack2();
        }
        return stack2.pop();
    }

    /*
     * @return: An integer
     */
    public int top() {
        // write your code here
        if(stack2.empty()){
            stack1Tostack2();
        }
        return stack2.peek();
    }
}