java生产者消费者问题（线程同步与线程等待的应用）

生产者

1/**
2 * 类说明：生产者
3 * 
4 * @author 作者: user
5 * @version 创建时间：2011-4-5 下午01:48:11
6 */
7public class Producer implements Runnable {
8	private SyncStack ss;
9	private int num;
10	private static int counter = 1;
11	public Producer(SyncStack ss) {
12		this.ss = ss;
13		num = counter++;
14	}
15	@Override
16	public void run() {
17		char c;
18		for (int i = 0; i < 10; i++) {
19			c = (char) (Math.random() * 26 + 'A');
20			ss.push(c);//向堆栈中添加数据
21			System.out.println("生产者 " + num + ": " + c);
22			try {
23				Thread.sleep((int) (Math.random() * 300));
24			} catch (InterruptedException e) {
25				e.printStackTrace();
26			}
27		}
28	}
29}

消费者

1/**
2 * 类说明：消费者
3 * 
4 * @author 作者: user
5 * @version 创建时间：2011-4-5 下午01:56:18
6 */
7public class Consumer implements Runnable {
8	private SyncStack ss;//堆栈对象
9	private int num;
10	private static int counter = 1;
11	public Consumer(SyncStack ss) {
12		this.ss = ss;
13		num = counter++;
14	}
15	@Override
16	public void run() {
17		char c;
18		for (int i = 0; i < 10; i++) {
19			c = ss.pop();//从堆栈中取数据
20			System.out.println("消费者 " + num + ": " + c);
21			try {
22				Thread.sleep((int) (Math.random() * 200));
23			} catch (InterruptedException e) {
24				e.printStackTrace();
25			}
26		}
27	}
28}

堆栈类

1import java.util.ArrayList;
2import java.util.List;
3/**
4 * 类说明：堆栈类
5 * 
6 * @author 作者: user
7 * @version 创建时间：2011-4-5 下午01:17:48
8 */
9public class SyncStack {
10	private List<Character> buffer = new ArrayList<Character>();
11	public SyncStack() {
12	}
13	// 堆栈取数据
14	public synchronized char pop() {
15		char c;
16		if (buffer.size() == 0) {
17			try {
18				System.out.println(Thread.currentThread().getName()
19						+ " 正在等待 ……………………");
20				this.wait();// 如果堆栈中没有数据 则线程等待
21			} catch (Exception e) {
22				e.printStackTrace();
23			}
24		}
25		c = ((Character) buffer.get(buffer.size() - 1)).charValue();
26		buffer.remove(buffer.size() - 1);
27		return c;
28	}
29	// 向堆栈中添加数据
30	public synchronized void push(char c) {
31		this.notify();// 唤醒在此对象监视器上等待的单个线程
32		Character ch = new Character(c);
33		buffer.add(ch);
34	}
35}

主方法

1/**
2 * 类说明：
3 * 
4 * @author 作者: user
5 * @version 创建时间：2011-4-5 下午01:59:54
6 */
7public class Main {
8	/**
9	 * @param args
10	 */
11	public static void main(String[] args) {
12		SyncStack ss = new SyncStack();
13		//生产者p
14		Producer p = new Producer(ss);
15		Thread t1 = new Thread(p);
16		t1.start();
17		//生产者p2
18		Producer p2 = new Producer(ss);
19		Thread t3 = new Thread(p2);
20		t3.start();
21		//消费者1
22		Consumer c = new Consumer(ss);
23		Thread t2 = new Thread(c);
24		t2.setName("消费者1 ");
25		t2.start();
26		//消费者1
27		Consumer c2 = new Consumer(ss);
28		Thread t4 = new Thread(c2);
29		t4.setName("消费者2 ");
30		t4.start();
31	}
32}