为对象创建堆栈类

import java.util.*;/*来自 n o w j a v a . c o m - 时代Java*/


class Stack {

    private List<Object> items;


    public Stack(int size) {

        items = new ArrayList<Object>();

    }


    public void push(Object item) {

        items.add(item);

    }


    public Object pop() {

        if (items.size() == 0)

            throw new EmptyStackException();

        return items.remove(items.size() - 1);

    }/**来自 时代Java公众号 - N o w J a  v a . c o m**/


    public boolean isEmpty() {

        return items.isEmpty();

    }

}

public class StackTest {

    public static void main(String[] args) {

        Stack s = new Stack(3);

        s.push("hi");

        s.push("hello");

        s.push("good day");

        System.out.format("%s%n", s.pop());

        System.out.format("%s%n", s.pop());

        System.out.format("%s%n", s.pop());

    }

}