Stack in Java

import java.util.ArrayList;
import java.util.EmptyStackException;

/* Stack class
 * A basic stack, you can push items in, last in, is first out.
 * 
 */
public class Stack {
 /// stores my data member in the stack
 private ArrayList mItems = new ArrayList();
 
 public Stack()
 {
 }
/* empty
 * -returns true if there are 0 items in the stack
 * other wise false
 */
 public boolean empty()
 {
  return mItems.isEmpty();  
 }
 /* size
  * -returns the number of items in the stack
  */
 public int size()
 {
  return mItems.size();  
 }
 /*push
  * -adds an object to the Top of the stack
  */
 public void push(Object obj)
 {
  mItems.add(obj);
 }
 /*pop
  * -removes the top object from the stack and returns it
  * throws EmptyStackException if stack is empty
  */
 public Object pop()
 {
  if (this.empty()) throw new EmptyStackException();
  
  return mItems.remove(mItems.size()-1);
  
 }
 /*peek
  * -returns the current top object in the stack
  * DOES NOT REMOVE IT
  */
 public Object peek()
 {
  if (this.empty()) throw new EmptyStackException();
  
  return mItems.get(mItems.size()-1);
 }
}