Stacks in Java

import java.util.Stack;  import java.util.Iterator;import java.util.ListIterator;public class Main{    public static void main(String[] args) {        System.out.println("is stack empty:");        Stack  stk= new Stack();        stk.push(78);          stk.push(113);        stk.push(112);        stk.push("books:");        stk.push("book1");        stk.push("book2");        stk.push("book3");        int location = stk.search("book1");  System.out.println("Location of Book1: " + location);           //System.out.println(result);    //  stk.peek();    System.out.println(stk.size());    //iterating the stack     Iterator iterator = stk.iterator();   while(iterator.hasNext())  {  Object values = iterator.next();  System.out.println(values);   }    ListIterator ListIterator = stk.listIterator(stk.size());  System.out.println("Iteration over the Stack from top to bottom:");  while (ListIterator.hasPrevious())   {  Object listi = ListIterator.previous();  System.out.println(listi);  }      }}

// implementing using Arrays class Stack{    //Max- maximum Size af array    static final int MAX = 1000;    // or we can take double the length of Stack itself    int top;    int a[] = new int[MAX];    //  isempdty condition     boolean isEmpty()    {        return (top < 0);    }    Stack()    {        top = -1;    }  //push condition    boolean push(int x)    {        //top should be less than Max, maximum length of Array        if (top >= (MAX - 1)) {            System.out.println("Stack Overflow");            return false;        }        else {            a[++top] = x;            System.out.println(x + " pushed into stack");            return true;        }    }    // pop condition    int pop()    {        if (top < 0) {            System.out.println("Stack Underflow");            return 0;        }        else {            int x = a[top--];            return x;        }    }    //peek condition     int peek()    {        if (top < 0) {            System.out.println("Stack Underflow");            return 0;        }        else {            int x = a[top];            return x;        }    }    // printing the stack     void print(){    for(int i = top;i>-1;i--){      System.out.print(" "+ a[i]);    }  }}//Main program public class Main{    // choose the length of stack/arrays    public static void main(String[] args) {        Stack stk = new Stack();        stk.push(10);        stk.push(1);        stk.push(2);        System.out.println(stk.pop() + " Popped from stack");         System.out.print("Elements present in stack :");        stk.print();    }}