Stack generic class declaration - Java Object Oriented Design

Description

Stack generic class declaration
Demo Code

import java.util.ArrayList;

class EmptyStackException extends RuntimeException
{
   // no-argument constructor
   public EmptyStackException()
   {/*from  www.jav a2s .c  o m*/
      this("Stack is empty");
   } 

   // one-argument constructor
   public EmptyStackException(String message)
   {
      super(message);
   }
}
class Stack<T>  
{
   private final ArrayList<T> elements; // ArrayList stores stack elements

   // no-argument constructor creates a stack of the default size
   public Stack()
   {
      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); 
   }
}

public class Main 
{
   public static void main(String[] args) 
   {
      double[] doubleElements = {1.1, 2.2, 3.3, 4.4, 5.5};
      int[] 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
      testPushDouble(doubleStack, doubleElements); 
      testPopDouble(doubleStack); // pop from doubleStack

      // push elements of integerElements onto integerStack
      testPushInteger(integerStack, integerElements); 
      testPopInteger(integerStack); // pop from integerStack
   } 

   // test push method with double stack
   private static void testPushDouble(Stack<Double> stack, double[] values)
   {
      System.out.printf("%nPushing elements onto doubleStack%n");

      // push elements to Stack
      for (double value : values)
      {
         System.out.printf("%.1f ", value);
         stack.push(value); // push onto doubleStack
      }
   }

   // test pop method with double stack
   private static void testPopDouble(Stack<Double> stack)
   {
      // pop elements from stack
      try
      {
         System.out.printf("%nPopping elements from doubleStack%n");
         double popValue; // store element removed from stack

         // remove all elements from Stack
         while (true)
         {
            popValue = stack.pop(); // pop from doubleStack
            System.out.printf("%.1f ", popValue); 
         }
      }
      catch(EmptyStackException emptyStackException)
      {
         System.err.println();
         emptyStackException.printStackTrace();
      } 
   } 

   // test push method with integer stack
   private static void testPushInteger(
      Stack<Integer> stack, int[] values)
   {
      System.out.printf("%nPushing elements onto integerStack%n");

      // push elements to Stack
      for (int value : values)
      {
         System.out.printf("%d ", value);
         stack.push(value); // push onto integerStack
      } 
   }

   // test pop method with integer stack
   private static void testPopInteger(Stack<Integer> stack)
   {
      // pop elements from stack
      try
      {
         System.out.printf("%nPopping elements from integerStack%n");
         int popValue; // store element removed from stack

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

Description

Demo Code

Result

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