Test generic Stack class with generic method - Java Object Oriented Design

Description

Test generic Stack class with generic method
Demo Code

import java.util.ArrayList;

class Stack<T>  
{
   private final ArrayList<T> elements; // ArrayList stores stack elements

   // no-argument constructor creates a stack of the default size
   public Stack()
   {// w w w.  ja va  2s .c  o m
      this(10); // default stack size
   } 

   // constructor creates a stack of the specified number of elements
   public Stack(int capacity)
   {
      int initCapacity = capacity > 0 ? capacity : 10; // validate
      elements = new ArrayList<T>(initCapacity); // create ArrayList
   }

   // push element onto stack
   public void push(T pushValue)
   {
      elements.add(pushValue); // place pushValue on Stack
   } 

   // return the top element if not empty; else throw EmptyStackException
   public T pop()
   {
      if (elements.isEmpty()) // if stack is empty
         throw new EmptyStackException("Stack is empty, cannot pop");

      // remove and return top element of Stack
      return elements.remove(elements.size() - 1); 
   }
}
 class EmptyStackException extends RuntimeException
{
   // no-argument constructor
   public EmptyStackException()
   {
      this("Stack is empty");
   } 

   // one-argument constructor
   public EmptyStackException(String exception)
   {
      super(exception);
   } 
}

public class Main 
{
   public static void main(String[] args) 
   {
      Double[] doubleElements = {1.1, 2.2, 3.3, 4.4, 5.5};
      Integer[] integerElements = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
      
      // Create a Stack<Double> and a Stack<Integer>
      Stack<Double> doubleStack = new Stack<>(5); 
      Stack<Integer> integerStack = new Stack<>(); 

      // push elements of doubleElements onto doubleStack
      testPush("doubleStack", doubleStack, doubleElements);
      testPop("doubleStack", doubleStack); // pop from doubleStack

      // push elements of integerElements onto integerStack
      testPush("integerStack", integerStack, integerElements);
      testPop("integerStack", integerStack); // pop from integerStack
   } 

   // generic method testPush pushes elements onto a Stack
   public static <T> void testPush(String name , Stack<T> stack, 
      T[] elements)
   {
      System.out.printf("%nPushing elements onto %s%n", name);

      // push elements onto Stack
      for (T element : elements)
      {
         System.out.printf("%s ", element);
         stack.push(element); // push element onto stack
      } 
   } 

   // generic method testPop pops elements from a Stack
   public static <T> void testPop(String name, Stack<T> stack)
   {
      // pop elements from stack
      try
      {
         System.out.printf("%nPopping elements from %s%n", name);
         T popValue; // store element removed from stack

         // remove all elements from Stack
         while (true)
         {
            popValue = stack.pop(); // pop from stack
            System.out.printf("%s ", popValue);
         } 
      }
      catch(EmptyStackException emptyStackException)
      {
         System.out.println();
         emptyStackException.printStackTrace();
      }
   }
}
Test generic Stack class with generic method - Java Object Oriented Design

Description

Demo Code

Result

Related Tutorials
