生产者消费者实例

生产者消费者实例

代码参考了： http://blog.csdn.net/monkey_d_meng/article/details/6251879/

并在此基础上做了改动

用wait()、notify()、notifyAll()方法写（在代码中被注释了）。

用Lock、ReentrantLock、await()、signalAll()写

类图如下：



代码如下：

import java.util.LinkedList;

import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.Condition;

abstract class People { // 增加了一个抽象类
int num = 0;
public void produce(int num){}
public void consume(int num){}

public void setNum(int num) {
this.num = num;
}

public int getNum() {
return num;
}
}

class Producer extends People implements Runnable {
private Storage storage;

public Producer(Storage storage) {
this.storage = storage;
}

@Override
public void produce(int num) {
storage.produce(num);
}

@Override
public void run() {
produce(num);
}
}

class Consumer extends People implements Runnable { // 改用Runnable接口
private Storage storage;

public Consumer(Storage storage) {
this.storage = storage;
}

@Override
public void consume(int num) {
storage.consume(num);
}

@Override
public void run() {
consume(num);
}
}

public class Storage {

private final int MAX_SIZE = 100; // 仓库的最大存储量
private LinkedList<Object> list = new LinkedList();

private final Lock lock = new ReentrantLock();
private final Condition full = lock.newCondition();
private final Condition empty = lock.newCondition();

public void produce(int num) { // 生产num个产品
//      synchronized(list) { // 同步代码块

lock.lock();

while(list.size() + num > MAX_SIZE) { // 如果仓库剩余容量不足
System.out.println("【要生产的产品数量】：" + num + " 【库存量】："
+ list.size() + "  暂时不能执行生产任务");
try{
//                  list.wait();
full.await();
}catch(InterruptedException e) {
e.printStackTrace();
}
}
for(int i = 0; i < num; i++) {
list.add(new Object());
}
System.out.println("【已经生产产品数】：" + num + " 【现仓储量为】:" + list.size());
//          list.notifyAll();

full.signalAll();
empty.signalAll();
lock.unlock();
//      }
}

public void consume(int num) { // 消费num个产品
//      synchronized(list) {
lock.lock();
while(list.size() < num) {
System.out.println("【要消费的产品数量】:" + num + " 【库存量】:"
+ list.size() + " 暂时不能执行消费任务!");
try {
//                  list.wait();
empty.await();
}catch(InterruptedException e) {
e.printStackTrace();
}
}
for(int i = 0; i < num; i++) {
list.remove();
}
System.out.println("【已经消费产品数】:" + num + " 【现仓储量为】:" + list.size());
//          list.notifyAll();

full.signalAll();
empty.signalAll();
lock.unlock();
//      }
}

public static void main(String[] args) {
// TODO Auto-generated method stub

// 仓库对象
Storage storage = new Storage();

// 生产者对象
Producer p1 = new Producer(storage);
Producer p2 = new Producer(storage);
Producer p3 = new Producer(storage);
Producer p4 = new Producer(storage);
Producer p5 = new Producer(storage);
Producer p6 = new Producer(storage);
Producer p7 = new Producer(storage);

// 消费者对象
Consumer c1 = new Consumer(storage);
Consumer c2 = new Consumer(storage);
Consumer c3 = new Consumer(storage);

// 设置生产者产品生产数量
p1.setNum(60);
p2.setNum(70);
p3.setNum(80);
p4.setNum(10);
p5.setNum(10);
p6.setNum(10);
p7.setNum(80);

// 设置消费者产品消费数量
c1.setNum(50);
c2.setNum(20);
c3.setNum(30);

// 线程开始执行
new Thread(c1, "c1").start();
new Thread(c2, "c2").start();
new Thread(c3, "c3").start();

new Thread(p1, "p1").start();
new Thread(p2, "p2").start();
new Thread(p3, "p3").start();
new Thread(p4, "p4").start();
new Thread(p5, "p5").start();
new Thread(p6, "p6").start();
new Thread(p7, "p7").start();

}

}