#生產者和消費者問題 ``` package 生產者消費者; public class ProducerConsumerTest { public static void main(String[] args) { PublicResource resource = new PublicResource(); new Thread(new ProducerThread(resource)).start(); new Thread(new ConsumerThread(resource)).start(); new Thread(new ProducerThread(resource)).start(); new Thread(new ConsumerThread(resource)).start(); new Thread(new ProducerThread(resource)).start(); new Thread(new ConsumerThread(resource)).start(); } } ``` ``` package 生產者消費者; /** * 生產者線程，負責生產公共資源 * @author dream * */ public class ProducerThread implements Runnable{ private PublicResource resource; public ProducerThread(PublicResource resource) { this.resource = resource; } @Override public void run() { while (true) { try { Thread.sleep((long) (Math.random() * 1000)); } catch (InterruptedException e) { e.printStackTrace(); } resource.increase(); } } } ``` ``` package 生產者消費者; /** * 消費者線程，負責消費公共資源 * @author dream * */ public class ConsumerThread implements Runnable{ private PublicResource resource; public ConsumerThread(PublicResource resource) { this.resource = resource; } @Override public void run() { while (true) { try { Thread.sleep((long) (Math.random() * 1000)); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } resource.decrease(); } } } ``` ``` package 生產者消費者; /** * 公共資源類 * @author dream * */ public class PublicResource { private int number = 0; private int size = 10; /** * 增加公共資源 */ public synchronized void increase() { while (number >= size) { try { wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } number++; System.out.println("生產了1個，總共有" + number); notifyAll(); } } /** * 減少公共資源 */ public synchronized void decrease() { while (number <= 0) { try { wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } number--; System.out.println("消費了1個，總共有" + number); notifyAll(); } } ```