java多线程 消费者-生产者

java多线程一般都会讲消费者-生产者模型

生产者与消费者模型中，要保证以下几点：
1 同一时间内只能有一个生产者生产
2 同一时间内只能有一个消费者消费
3 生产者生产的同时消费者不能消费
4 消息队列满时生产者不能继续生产
5 消息队列空时消费者不能继续消费

参考了下网上一个代码实例http://www.talented.com.cn/archives/2007/5/16_141.html 发现作者写得有问题 修改了一些代码 现在ok了

----------------------------------------------------Message类

package com.example.test;

public class Message {

public static int id;
public String content;

public String getContent() {
return content;
}

public void setContent(String content) {
this.content = content;
}

public int getId() {
return id;
}

public void setId(int id) {
Message.id = id;
}
}

----------------------------------------------------Queue类

package com.example.test;

import java.util.ArrayList;
import java.util.List;

public class Queue {
List<Message> queue = new ArrayList<Message>();

/** 队列中message对象的最大值,默认为5 */
int maxMessageNum = 5;

public synchronized void produce(Message message) {

this.notifyAll();
while (queue.size() == maxMessageNum) {
System.out.println(Thread.currentThread().getName()
+ " 队列满！等待中。。。");
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
queue.add(message);
System.out.println(Thread.currentThread().getName() + "正在生产"
+ message.getContent() + "。。。 ,当前个数:" + getCount());

}

public synchronized void consume() {

this.notifyAll();
while (queue.size() == 0) {
System.out.println(Thread.currentThread().getName()
+ " 队列空！等待中。。。");
try {
System.out.println("begin!");
wait();
System.out.println("end!");
} catch (InterruptedException e) {
e.printStackTrace();
}
}

Message message = queue.get(0);
queue.remove(0);
System.out.println(Thread.currentThread().getName() + "正在消费"
+ message.getContent() + "。。。 ,当前个数: " + getCount());

}

public synchronized int getCount() {
return queue.size();
}
}

----------------------------------------------------Test类

package com.example.test;

public class Test {

public static void main(String[] args) {

Queue Q = new Queue();

Producer wQ1 = new Producer(Q);
Producer wQ2 = new Producer(Q);

Consumer rQ1 = new Consumer(Q);
Consumer rQ2 = new Consumer(Q);
Consumer rQ3 = new Consumer(Q);

Thread threadWQ1 = new Thread(wQ1, "thread-wQ1");
Thread threadWQ2 = new Thread(wQ2, "thread-wQ2");

Thread threadRQ1 = new Thread(rQ1, "thread-rQ1");
Thread threadRQ2 = new Thread(rQ2, "thread-rQ2");
Thread threadRQ3 = new Thread(rQ3, "thread-rQ3");

threadWQ1.start();
threadWQ2.start();

threadRQ1.start();
threadRQ2.start();
threadRQ3.start();
}
}

class Producer extends Thread {

private Queue queue;

Producer(Queue queue) {
this.queue = queue;
}

public void run() {

while (true) {
Message message = new Message();
message.setId(++Message.id);
message.setContent("food"+Message.id);
queue.produce(message);
try {
sleep(100);
} catch (Exception e) {
}
}

}
}

class Consumer extends Thread {
private Queue queue;

Consumer(Queue queue) {
this.queue = queue;
}

public void run() {
while (true) {
queue.consume();
try {
sleep(100);
} catch (Exception e) {
}

}
}
}

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/bnuchampion/archive/2008/01/04/2025591.aspx