标签：ret dex 信号 成员 tar consumer override start span
线程间通信可以通过发送信号，发送信号的一个简单方式是在共享对象的变量里设置信号值。线程A在一个同步块里设置boolean型成员变量hasDataToProcess为true，线程B也在同步代码块里读取hasDataToProcess这个成员变量。这个简单的例子使用了一个持有信号的对象，并提供了set和get方法。
public class MySignal1 { //共享的变量 private boolean hasDataToProcess = false; //取值 public boolean getHasDataProcess() { return hasDataToProcess; } //存值 public void setHasDataToProcess(boolean hasDataToProcess) { this.hasDataToProcess = hasDataToProcess; } public static void main(String[] args) { //同一个对象 final MySignal1 my = new MySignal1(); //线程1设置hasDataToProcess值为true final Thread t1 = new Thread(new Runnable() { @Override public void run() { my.setHasDataToProcess(true); } }); t1.start(); //线程2取这个值hasDataToProcess Thread t2 = new Thread(new Runnable() { @Override public void run() { try { //等待线程1完成后取值 t1.join(); } catch (InterruptedException e) { e.printStackTrace(); } my.getHasDataProcess(); System.out.println("t1改变以后的值："+my.getHasDataProcess()); } }); t2.start(); } }
运行结果如下：
t1改变以后的值：true
以资源为例，生产者生产一个资源，通知消费者就消费掉一个资源，生产者继续生产资源，消费者消费资源，以此循环，代码如下。
import sun.security.util.Password; //资源类 class Resource { private String name; private int count = 1; private boolean flag = false; public synchronized void set(String name) { //生产资源 while (flag) { try { //线程等待 wait(); } catch (InterruptedException e) { } } this.name = name + "----" + count + "+++++"; System.out.println(Thread.currentThread().getName() + "..生产者..." + this.name); flag = true; //唤醒等待中的消费者 this.notifyAll(); } public synchronized void out() { //消费资源 while (!flag) { try { //线程等待，生产者生产资源 wait(); } catch (InterruptedException e) { } } System.out.println(Thread.currentThread().getName() + "...消费者..." + this.name); flag = false; //唤醒消费者，生产资源 this.notifyAll(); } } //生产者 class Producer implements Runnable { private Resource rs; public Producer(Resource rs) { this.rs = rs; } //生产者生产资源 @Override public void run() { while (true) { rs.set("商品"); } } } //消费者消费资源 class Consumer implements Runnable { private Resource rs; public Consumer(Resource rs) { this.rs = rs; } //消费者消费资源 @Override public void run() { while (true) { rs.out(); } } } public class ProducerConsumerDemo { public static void main(String[] args) { Resource r = new Resource(); Producer p = new Producer(r); Consumer c = new Consumer(r); Thread t1 = new Thread(p); Thread t2 = new Thread(c); t1.start(); t2.start(); } }
运行结果如下：
Thread-0..生产者...商品----1+++++ Thread-1...消费者...商品----1+++++ Thread-0..生产者...商品----1+++++ Thread-1...消费者...商品----1+++++ Thread-0..生产者...商品----1+++++ Thread-1...消费者...商品----1+++++ Thread-0..生产者...商品----1+++++
标签：ret dex 信号 成员 tar consumer override start span
原文地址：https://www.cnblogs.com/scar1et/p/11909355.html
