生产者

/**
 * 类说明：生产者
 * 
 * @author 作者: user
 * @version 创建时间：2011-4-5 下午01:48:11
 */
public class Producer implements Runnable {
    private SyncStack ss;
    private int num;
    private static int counter = 1;
    public Producer(SyncStack ss) {
        this.ss = ss;
        num = counter++;
    }
    @Override
    public void run() {
        char c;
        for (int i = 0; i < 10; i++) {
            c = (char) (Math.random() * 26 + 'A');
            ss.push(c);//向堆栈中添加数据
            System.out.println("生产者 " + num + ": " + c);
            try {
                Thread.sleep((int) (Math.random() * 300));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

消费者

/**
 * 类说明：消费者
 * 
 * @author 作者: user
 * @version 创建时间：2011-4-5 下午01:56:18
 */
public class Consumer implements Runnable {
    private SyncStack ss;//堆栈对象
    private int num;
    private static int counter = 1;
    public Consumer(SyncStack ss) {
        this.ss = ss;
        num = counter++;
    }
    @Override
    public void run() {
        char c;
        for (int i = 0; i < 10; i++) {
            c = ss.pop();//从堆栈中取数据
            System.out.println("消费者 " + num + ": " + c);
            try {
                Thread.sleep((int) (Math.random() * 200));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

堆栈类

import java.util.ArrayList;
import java.util.List;
/**
 * 类说明：堆栈类
 * 
 * @author 作者: user
 * @version 创建时间：2011-4-5 下午01:17:48
 */
public class SyncStack {
    private List<Character> buffer = new ArrayList<Character>();
    public SyncStack() {
    }
    // 堆栈取数据
    public synchronized char pop() {
        char c;
        if (buffer.size() == 0) {
            try {
                System.out.println(Thread.currentThread().getName()
                        + " 正在等待 ……………………");
                this.wait();// 如果堆栈中没有数据 则线程等待
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        c = ((Character) buffer.get(buffer.size() - 1)).charValue();
        buffer.remove(buffer.size() - 1);
        return c;
    }
    // 向堆栈中添加数据
    public synchronized void push(char c) {
        this.notify();// 唤醒在此对象监视器上等待的单个线程
        Character ch = new Character(c);
        buffer.add(ch);
    }
}

主方法

/**
 * 类说明：
 * 
 * @author 作者: user
 * @version 创建时间：2011-4-5 下午01:59:54
 */
public class Main {
    /**
     * @param args
     */
    public static void main(String[] args) {
        SyncStack ss = new SyncStack();
        //生产者p
        Producer p = new Producer(ss);
        Thread t1 = new Thread(p);
        t1.start();
        //生产者p2
        Producer p2 = new Producer(ss);
        Thread t3 = new Thread(p2);
        t3.start();
        //消费者1
        Consumer c = new Consumer(ss);
        Thread t2 = new Thread(c);
        t2.setName("消费者1 ");
        t2.start();
        //消费者1
        Consumer c2 = new Consumer(ss);
        Thread t4 = new Thread(c2);
        t4.setName("消费者2 ");
        t4.start();
    }
}