生产者和消费者
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如果生产者的队列满了(while循环判断是否满)，则等待。如果生产者的队列没满，则生产数据并唤醒消费者进行消费。
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如果消费者的队列空了(while循环判断是否空)，则等待。如果消费者的队列没空，则消费数据并唤醒生产者进行生产。
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package test;
import java.util.Random; import java.util.Vector; import java.util.concurrent.atomic.AtomicInteger;
public class Producer implements Runnable {
// true--->生产者一直执行，false--->停掉生产者 private volatile boolean isRunning = true;
// 公共资源 private final Vector sharedQueue;
// 公共资源的最大数量 private final int SIZE;
// 生产数据 private static AtomicInteger count = new AtomicInteger();
public Producer(Vector sharedQueue, int SIZE) { this.sharedQueue = sharedQueue; this.SIZE = SIZE; }
@Override public void run() { int data; Random r = new Random();
System.out.println("start producer id = " + Thread.currentThread().getId()); try { while (isRunning) { // 模拟延迟 Thread.sleep(r.nextInt(1000));
// 当队列满时阻塞等待 while (sharedQueue.size() == SIZE) { synchronized (sharedQueue) { System.out.println("Queue is full, producer " + Thread.currentThread().getId() + " is waiting, size：" + sharedQueue.size()); sharedQueue.wait(); } }
// 队列不满时持续创造新元素 synchronized (sharedQueue) { // 生产数据 data = count.incrementAndGet(); sharedQueue.add(data);
System.out.println("producer create data:" + data + ", size：" + sharedQueue.size()); sharedQueue.notifyAll(); } } } catch (InterruptedException e) { e.printStackTrace(); Thread.currentThread().interrupted(); } }
public void stop() { isRunning = false; } }
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package test;
import java.util.Random; import java.util.Vector;
public class Consumer implements Runnable {
// 公共资源 private final Vector sharedQueue;
public Consumer(Vector sharedQueue) { this.sharedQueue = sharedQueue; }
@Override public void run() {
Random r = new Random();
System.out.println("start consumer id = " + Thread.currentThread().getId()); try { while (true) { // 模拟延迟 Thread.sleep(r.nextInt(1000));
// 当队列空时阻塞等待 while (sharedQueue.isEmpty()) { synchronized (sharedQueue) { System.out.println("Queue is empty, consumer " + Thread.currentThread().getId() + " is waiting, size：" + sharedQueue.size()); sharedQueue.wait(); } } // 队列不空时持续消费元素 synchronized (sharedQueue) { System.out.println("consumer consume data：" + sharedQueue.remove(0) + ", size：" + sharedQueue.size()); sharedQueue.notifyAll(); } } } catch (InterruptedException e) { e.printStackTrace(); Thread.currentThread().interrupt(); } } }
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package test;
import java.util.Vector; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors;
public class Test2 {
public static void main(String[] args) throws InterruptedException {
// 1.构建内存缓冲区 Vector sharedQueue = new Vector(); int size = 4;
// 2.建立线程池和线程 ExecutorService service = Executors.newCachedThreadPool(); Producer prodThread1 = new Producer(sharedQueue, size); Producer prodThread2 = new Producer(sharedQueue, size); Producer prodThread3 = new Producer(sharedQueue, size); Consumer consThread1 = new Consumer(sharedQueue); Consumer consThread2 = new Consumer(sharedQueue); Consumer consThread3 = new Consumer(sharedQueue); service.execute(prodThread1); service.execute(prodThread2); service.execute(prodThread3); service.execute(consThread1); service.execute(consThread2); service.execute(consThread3);
// 3.睡一会儿然后尝试停止生产者(结束循环) Thread.sleep(10 * 1000); prodThread1.stop(); prodThread2.stop(); prodThread3.stop();
// 4.再睡一会儿关闭线程池 Thread.sleep(3000);
// 5.shutdown()等待任务执行完才中断线程(因为消费者一直在运行的，所以会发现程序无法结束) service.shutdown();
} }
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