Java Program to Implement Stack API

This Java program Implements Stack API.The Stack class represents a last-in-first-out (LIFO) stack of objects. It extends class Vector with five operations that allow a vector to be treated as a stack. The usual push and pop operations are provided, as well as a method to peek at the top item on the stack, a method to test for whether the stack is empty, and a method to search the stack for an item and discover how far it is from the top.

Here is the source code of the Java Program to Implement Stack API.The Java program is successfully compiled and run on a Linux system. The program output is also shown below.

import java.util.Stack;
 
public class StackImpl<E>
{
    private Stack<E> stack;
 
    /** Creates an empty Stack. **/
    public StackImpl()
    {
        stack = new Stack<E>();
    }
 
    /** Tests if this stack is empty. **/
    public boolean empty()
    {
        return stack.empty();
    }
 
    /**
     * Looks at the object at the top of this stack without removing it from the
     * stack.
     **/
    public E peek()
    {
        return stack.peek();
    }
 
    /**
     * Removes the object at the top of this stack and returns that object as
     * the value of this function.
     **/
    public E pop()
    {
        return stack.pop();
    }
 
    /** Pushes an item onto the top of this stack. **/
    public E push(E item)
    {
        return stack.push(item);
    }
 
    /** Returns the 1-based position where an object is on this stack. **/
    public int search(Object o)
    {
        return stack.search(o);
    }
 
    public static void main(String...arg)
    {
        StackImpl<Integer> stack = new StackImpl<Integer>();
        System.out.println("element pushed : " + stack.push(3));
        System.out.println("element pushed : " + stack.push(4));
        System.out.println("element pushed : " + stack.push(-19));
        System.out.println("element pushed : " + stack.push(349));
        System.out.println("element pushed : " + stack.push(35));
        System.out.println("element poped : " + stack.pop());
        System.out.println("element poped : " + stack.pop());
        System.out.println("Element peek : " + stack.peek());
        System.out.println("position of element 349 " + stack.search(3));
        while (!stack.empty())
        {
            System.out.println("element poped : " + stack.pop());
        }
    }
}

$ javac StackImpl.java
$ java StackImpl
element pushed : 3
element pushed : 4
element pushed : -19
element pushed : 349
element pushed : 35
element poped : 35
element poped : 349
Element peek : -19
position of element 349 3
element poped : -19
element poped : 4
element poped : 3