多线程学习-坏人

本文主要是介绍多线程学习-坏人，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

学习原：来自哔哩哔哩：狂神

1.学习 Runnable

2.问题

1.问题1

java代码：

package com.sunweihao.example;
//多个线程同时操作一个对象
//拍电影的例子，先到先拍片
public class TestThread4 implements Runnable {//有十部电影private int ticketNums=10;@Overridepublic void run() {while (true){if (ticketNums<=0){break;}try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println(Thread.currentThread().getName()+"---->拍了第"+ticketNums--+"剧");}}public static void main(String[] args) {TestThread4 ticket=new TestThread4();new Thread(ticket,"颇多野老师").start();new Thread(ticket,"苍井空老湿").start();new Thread(ticket,"老司机").start();}
}

打印结果：
在这里插入图片描述

问题分析：
在这里插入图片描述

解决办法：

加锁

package com.sunweihao.example;
//多个线程同时操作一个对象
//拍电影的例子
public class TestThread4Improve implements Runnable {//有十部电影private int ticketNums=10;@Overridepublic void run() {play();}private synchronized void  play() {while (true){if (ticketNums<=0){break;}try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}System.out.println(Thread.currentThread().getName()+"---->拍了第"+ticketNums--+"剧");}}public static void main(String[] args) {TestThread4Improve ticket=new TestThread4Improve();new Thread(ticket,"颇多野老师").start();new Thread(ticket,"苍井空老湿").start();new Thread(ticket,"老司机").start();}
}

结果：
在这里插入图片描述

2.Thread下载

步骤：

1.导包
在这里插入图片描述
2.代码：下载文件

package com.sunweihao.example;import org.apache.commons.io.FileUtils;import java.io.File;
import java.io.IOException;
import java.net.URL;public class TestThread2 extends Thread {private String url;private String name;public TestThread2(String url,String name){this.url=url;this.name=name;//hhh}@Overridepublic void run() {WebDownloader webDownloader=new WebDownloader();webDownloader.downloader(url,name);System.out.println("下载了文件名为："+name);}public static void main(String[] args) {TestThread2 testThread1=new TestThread2("https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=3620297292,2452146774&fm=26&gp=0.jpg","苍井空老师");TestThread2 testThread2=new TestThread2("https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=3620297292,2452146774&fm=26&gp=0.jpg","颇多野老师");TestThread2 testThread3=new TestThread2("https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=3620297292,2452146774&fm=26&gp=0.jpg","孙伟豪老师");testThread1.start();testThread2.start();testThread3.start();}
}
class WebDownloader{//下载方法public void downloader(String url,String name){try {FileUtils.copyURLToFile(new URL(url),new File(name));} catch (IOException e) {e.printStackTrace();System.out.println("IO异常，download方法出现错误");}}
}

3.生产消费者模式

展示图

在这里插入图片描述

1.有个共同的操作

这里共同操作是TV
生产者：演员

class Player extends Thread{TV tv;public Player(TV tv){this.tv=tv;}@Overridepublic void run() {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}for (int i = 0; i < 20; i++) {if (i%2==0) {this.tv.play("快乐大本营播放中");}else {this.tv.play("抖音：记录美好生活");}}}
}

消费者：观众

class Watcher extends Thread{TV tv;public Watcher(TV tv){this.tv=tv;}@Overridepublic void run() {for (int i = 0; i < 20; i++) {tv.watch();}}
}

他们共同看TV

class TV{//演员表演，观众等待T//观众观看，演员等待FString voice;//表演的节目boolean flag=true;//表演public synchronized void play(String voice){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}//休眠if (!flag) {try {this.wait();} catch (InterruptedException e) {e.printStackTrace();}//等待}System.out.println("演员表演了："+voice);//通知观众观看this.notifyAll();//通知唤醒this.voice=voice;this.flag=!this.flag;}//观看public synchronized void watch(){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}//休眠if (flag) {try {this.wait();} catch (InterruptedException e) {e.printStackTrace();}//等待}System.out.println("观看了："+voice);//通知演员表演this.notifyAll();this.flag=!this.flag;}
}

关键代码介绍

1.this.wait()会导致休眠
2.this.notifyAll();//通知其他线程唤醒
3.notify();//通知一条线程唤醒

全部代码

package com.sunweihao.gaoji;
//测试生产者消费者问题2，信号灯法，标志位解决
public class TestPc2 {public static void main(String[] args) throws Exception {TV tv=new TV();new Player(tv).start();new Watcher(tv).start();}
}
//生产者-演员
class Player extends Thread{TV tv;public Player(TV tv){this.tv=tv;}@Overridepublic void run() {try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}for (int i = 0; i < 20; i++) {if (i%2==0) {this.tv.play("快乐大本营播放中");}else {this.tv.play("抖音：记录美好生活");}}}
}
//消费者-观众
class Watcher extends Thread{TV tv;public Watcher(TV tv){this.tv=tv;}@Overridepublic void run() {for (int i = 0; i < 20; i++) {tv.watch();}}
}
//产品-节目
class TV{//演员表演，观众等待T//观众观看，演员等待FString voice;//表演的节目boolean flag=true;//表演public synchronized void play(String voice){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}//休眠if (!flag) {try {this.wait();} catch (InterruptedException e) {e.printStackTrace();}//等待}System.out.println("演员表演了："+voice);//通知观众观看this.notifyAll();//通知唤醒this.voice=voice;this.flag=!this.flag;}//观看public synchronized void watch(){try {Thread.sleep(1000);} catch (InterruptedException e) {e.printStackTrace();}//休眠if (flag) {try {this.wait();} catch (InterruptedException e) {e.printStackTrace();}//等待}System.out.println("观看了："+voice);//通知演员表演this.notifyAll();this.flag=!this.flag;}
}