Java示例从堆栈中检索元素

import java.util.*;



public class Demo {

   static void showpush(Stack stack1, int a) {

      stack1.push(new Integer(a));

      System.out.println("push(" + a + ")");

      System.out.println("stack: " + stack1);

   }

   static void showpop(Stack stack1) {

      Integer a = (Integer) stack1.pop();

      System.out.println(a);

      System.out.println("stack: " + stack1);

   }

   public static void main(String args[]) {

      Stack stack1 = new Stack();

      System.out.println("stack: " + stack1);

      showpush(stack1, 40);

      showpush(stack1, 50);

      showpush(stack1, 60);

      showpop(stack1);

      showpop(stack1);

      showpop(stack1);

      try {

         showpop(stack1);

      } catch (EmptyStackException e) {

         System.out.println("it Is Empty Stack");

      }

   }

}