生产者－消费者问题－－解决方案（一）

生产者－消费者问题（producer - consumer）是一个著名的进程同步问题；今天我们用加入“”等待与唤醒“”来解决。

package zz;public class Producer extends Thread {private Box box;private String name;public Producer(Box b, String n) {box = b;name = n;}public void run() {for (int i = 1; i < 6; i++) {box.put(i);System.out.println("Producer " + name+ " produed: " + i);}try {sleep((int) (Math.random() * 100));} catch (InterruptedException e) {e.printStackTrace();}}}

package zz;class Consumer extends Thread {private Box box;private String name;public Consumer(Box b, String n) {box = b;name = n;}public void run() {int value = 0;for (int i = 1; i < 6; i++) {value = box.get();System.out.println("Consumer " + name+ " consumed: " + value);}try {sleep((int)(Math.random() * 100));} catch (InterruptedException e) {e.printStackTrace();}}}

package zz;public class Box{private int value;private boolean available = false;public synchronized int get() {//synchronized：给方法加锁while (available == false) {try {//等待生产者写入数据wait();} catch (InterruptedException e) {e.printStackTrace();}}available = false;//通知生产者数据已被取走，可以再次写入数据notifyAll();return value;}public synchronized void put(int value) {while (available == true) {try {//等待消费者取走数据wait();} catch (InterruptedException e) {e.printStackTrace();}}this.value = value;available = true;//通知消费者可以来取数据notifyAll();}}

package zz;public class ProducerConsumerTest {/** * 生产者/消费者问题 * @param args */public static void main(String[] args) {// TODO Auto-generated method stubBox box = new Box();Producer p = new Producer(box, "p");Consumer c = new Consumer(box, "c");p.start();c.start();}}