To find out if an element is on the stack: the search() method : Stack « Collections « Java Tutorial

public int search(Object element)

The element at the top of the stack is at position 1.

Position 2 is next, then 3, and so on.

If the requested object is not found on the stack, -1 is returned.

import java.util.Stack;

public class MainClass {
  public static void main (String args[]) {
    Stack s = new Stack();

    System.out.println("Next: " + s.peek());


    int count ="E");
    while (count != -1 && count > 1) {
Next: C
[A, B, C, E]

9.13.1.Stack Basics: last-in, first-out behavior
9.13.2.Adding Elements: To add an element to a stack, call the push() method
9.13.3.Removing Elements: To remove an element from the stack, the pop() method
9.13.4.If the size of the stack is zero, true is returned; otherwise, false is returned
9.13.5.Checking the Top: To get the element without removing: using the peek() method
9.13.6.To find out if an element is on the stack: the search() method
9.13.7.Demonstrate the generic Stack class.
9.13.8.A faster, smaller stack implementation.
9.13.9.A simple integer based stack.
9.13.10.A stack of simple integers
9.13.11.A very simple unsynchronized stack. This one is faster than the java.util-Version.
9.13.12.An implementation of the java.util.Stack based on an ArrayList instead of a Vector, so it is not synchronized to protect against multi-threaded access.
9.13.13.Character Stack
9.13.14.Growable Object stack with type specific access methods
9.13.15.Growable String stack with type specific access methods.
9.13.16.Growable int stack with type specific access methods
9.13.17.Stack for boolean values
9.13.18.extends ArrayList to create Stack