第十五话-Java线程

Thread类

自定义线程类继承Thread类
重写run()方法，编写线程执行体
创建线程对象，调用start()方法启动线程
不推荐使用：存在单继承局限性

package com.xie.thread;

public class DemoThread extends Thread{
    @Override
    public void run() {//run方法线程体
        for (int i = 0; i < 20; i++) {
            System.out.println("我在看代码。。。。");
        }
    }
    //cpu调度分配顺序执行
    public static void main(String[] args) {//main线程，主线程
        DemoThread demoThread = new DemoThread();//创建线程对象
        demoThread.start();//调用start()，开启线程
        for (int i = 0; i < 20; i++) {
            System.out.println("我在学习多线程开发。。。。");
        }
    }
}

网图下载案例

网上下载commons-io工具类
com下新建lib包
将commons-io-2.10.0.jar复制到lib包下
lib包右键Add as Library，然后jar包变成可查看
Structure里也能看到，Libraries下多了lib和commons-io包

package com.xie.thread;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;

public class DemoThread2 extends Thread{
    private String url; //网络图片地址
    private String name;//保存的文件名

    public DemoThread2(String url, String name) {
        this.url = url;
        this.name = name;
    }

    @Override
    public 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) {
        DemoThread2 t1 = new DemoThread2("https://img2.baidu.com/it/u=1814268193,3619863984&fm=253&fmt=auto&app=138&f=JPEG?w=632&h=500","picture1.jpg");
        DemoThread2 t2 = new DemoThread2("https://img0.baidu.com/it/u=925998594,1358415170&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=281","picture2.jpg");
        DemoThread2 t3 = new DemoThread2("https://img2.baidu.com/it/u=2147843660,3054818539&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=313","pciture3.jpg");
        t1.start();
        t2.start();
        t3.start();
    }
}

//下载器
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，downloader方法出现问题");
        }
    }
}

Runnable接口

定义MyRunnable类实现Runnable接口
实现run()方法，编写线程执行体
创建线程对象，new Thread传如Runnable实现类，再调用start()方法启动线程
推荐使用：避免单继承局限性，灵活方便，方便同一个对象被多个线程使用

package com.xie.thread;

public class DemoThread3 implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            System.out.println("我在看代码。。。。");
        }
    }

    public static void main(String[] args) {//main线程，主线程
        DemoThread3 demoThread3 = new DemoThread3();
        new Thread(demoThread3).start();
        for (int i = 0; i < 20; i++) {
            System.out.println("我在学习多线程开发。。。。");
        }
    }
}

线程并发问题

package com.xie.thread;

public class TestThread4 implements Runnable{

    private int ticketNums = 10;
    @Override
    public void run() {
        while (true){
            if(ticketNums<=0){
                break;
            }
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName()+"-->拿到第"+ticketNums--+"张票");
        }
    }

    public static void main(String[] args) {
        TestThread4 testThread4 = new TestThread4();
        new Thread(testThread4,"小明").start();
        new Thread(testThread4,"小李").start();
        new Thread(testThread4,"黄牛").start();
    }
}

模拟龟兔赛跑

package com.xie.thread;

public class Race implements Runnable{
    private static String winner;
    @Override
    public void run() {
        for (int i = 0; i <= 100; i++) {
            if(Thread.currentThread().getName().equals("兔子") && i%10==0){
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //判断比赛是否结束，如果结束，则停止程序
            boolean flag = gameOver(i);
            if(flag){
                break;
            }
            System.out.println(Thread.currentThread().getName()+"-->跑了"+i+"步");
        }
    }

    //判断比赛是否结束
    private boolean gameOver(int i){
        if(winner!=null){
            return true;
        }else{
            if(i>=100){
                winner = Thread.currentThread().getName();
                System.out.println(Thread.currentThread().getName()+"-->跑了"+i+"步");
                System.out.println("Winner is" + winner);
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
        Race race = new Race();
        new Thread(race,"兔子").start();
        new Thread(race,"乌龟").start();
    }
}

Callable接口

package com.xie.thread;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.concurrent.*;
/*
callable的好处：
1. 可以定义返回值
2. 可以抛出异常
 */
public class TestCallable implements Callable<Boolean> {
    private String url; //网络图片地址
    private String name;//保存的文件名

    public TestCallable(String url, String name) {
        this.url = url;
        this.name = name;
    }

    @Override
    public Boolean call() throws Exception {
        WebDownloader2 webDownloader = new WebDownloader2();
        webDownloader.downloader(url,name);
        System.out.println("下载了文件名为："+name);
        return true;
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        TestCallable t1 = new TestCallable("https://img2.baidu.com/it/u=1814268193,3619863984&fm=253&fmt=auto&app=138&f=JPEG?w=632&h=500","picture1.jpg");
        TestCallable t2 = new TestCallable("https://img0.baidu.com/it/u=925998594,1358415170&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=281","picture2.jpg");
        TestCallable t3 = new TestCallable("https://img2.baidu.com/it/u=2147843660,3054818539&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=313","pciture3.jpg");
        //1.创建执行服务
        ExecutorService ser = Executors.newFixedThreadPool(3);
        //2.提交执行
        Future<Boolean> r1 = ser.submit(t1);
        Future<Boolean> r2 = ser.submit(t2);
        Future<Boolean> r3 = ser.submit(t3);
        //3.获取结果
        boolean rs1 = r1.get();
        boolean rs2 = r2.get();
        boolean rs3 = r3.get();
        //4.关闭服务
        ser.shutdown();
    }
}
//下载器
class WebDownloader2{
    //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，downloader方法出现问题");
        }
    }
}

静态代理模式

真实对象和代理对象都要实现同一个接口
代理对象要代理真实角色
好处： - 代理对象可以做很多真实对象做不了的事情

- 真实对象专注做自己的事情

package com.xie.thread;

public class StaticProxy {
    public static void main(String[] args) {
//        WeddingCompany weddingCompany = new WeddingCompany(new You());
//        weddingCompany.HappyMarry();
        new WeddingCompany(new You()).HappyMarry();
        //对比线程,Thread是代理，传入Runnable接口匿名类，start方法实现真实对象run
        //new Thread( ()-> System.out.println("ceshi") ).start();
    }
}

interface Marry{
    void HappyMarry();
}

class You implements Marry{
    @Override
    public void HappyMarry() {
        System.out.println("结婚啦，超开心");
    }
}

class WeddingCompany implements Marry{

    private Marry target;

    public WeddingCompany(Marry target) {
        this.target = target;
    }

    @Override
    public void HappyMarry() {
        System.out.println("婚前布置");
        this.target.HappyMarry();
        System.out.println("婚后收钱");
    }
}

Lamda表达式

函数式接口：任何接口，如果只包含一个抽象方法，那就是函数式接口。
函数式接口可以通过lamda表达式创建接口的对象
好处：- 避免匿名内部类定义过多。- 代码更简洁

package com.xie.thread;

public class TestLamda2 {
    public static void main(String[] args) {
        ILove iLove = null;
        //匿名内部类方式实现，借用接口实现匿名内部类
        iLove = new ILove() {
            @Override
            public void love(int a, int b) {
                System.out.println("1i love you --"+a);
                System.out.println("1i love you too--"+b);
            }
        };
        iLove.love(10,20);
        System.out.println("--------");
        iLove = (a, b)-> {
            System.out.println("2i love you --"+a);
            System.out.println("2i love you too--"+b);
        };
        iLove.love(10,20);
        //总计：
        //lamda表达式如果是多行需要用代码块包裹，如果是一行可以去掉大括号
        //多个参数可以去掉参数类型，要去掉就必须全去掉，多个参数必须有括号，一个参数可以去掉括号
    }
}
//函数式接口
interface ILove{
    void love(int a,int b);
}

线程五大状态

线程方法

停止线程

package com.xie.thread;

public class TestStop implements Runnable{
    private boolean flag = true;
    @Override
    public void run() {
        int i = 0;
        while(flag){
            System.out.println("Thread...run" + i++);
        }
    }

    void stop(){
        this.flag = false;
    }

    public static void main(String[] args) {
        TestStop testStop = new TestStop();
        new Thread(testStop).start();
        for (int i = 0; i < 100; i++) {
            System.out.println("main执行"+i);
            if(i==90){
                testStop.stop();
                System.out.println("线程停止了");
            }
        }
    }
}

线程休眠-sleep

package com.xie.thread;

import java.text.SimpleDateFormat;
import java.util.Date;
//模拟倒计时
public class TestSleep {
    public static void main(String[] args) {
        Date startTime = new Date(System.currentTimeMillis());
        while(true){
            try {
                System.out.println(new SimpleDateFormat("HH:mm:ss").format(startTime));
                Thread.sleep(1000);
                startTime = new Date(System.currentTimeMillis());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

线程礼让-yield

让当前正在执行的线程暂停，但不阻塞，线程进入就绪状态，cpu重新调度。

package com.xie.thread;

public class TestYield {
    public static void main(String[] args) {
        MyYield myYield = new MyYield();
        new Thread(myYield,"a").start();
        new Thread(myYield,"b").start();
    }
}

class MyYield implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"线程开始执行");
        Thread.yield();//礼让
        System.out.println(Thread.currentThread().getName()+"线程停止执行");
    }
}

线程强制执行-join

Join合并线程，待此线程执行完成后，再执行其它线程，其它线程阻塞。

package com.xie.thread;

public class TestJoin implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            System.out.println("线程VIP"+i);
        }
    }
    public static void main(String[] args) throws InterruptedException {
        TestJoin testJoin = new TestJoin();
        Thread thread = new Thread(testJoin);
        thread.start();
        for (int i = 0; i < 100; i++) {
            if(i==10){
                thread.join();
            }
            System.out.println("main"+i);
        }
    }
}

观察线程状态

package com.xie.thread;

public class TestState {
    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(()->{
            for (int i = 0; i < 3; i++) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("//////////");
        });
        //观察线程状态
        Thread.State state = thread.getState();
        System.out.println(state);
        //线程启动后，观察线程状态
        thread.start();
        state = thread.getState();
        System.out.println(state);
        //线程不停止，就一直输出状态
        while (state != Thread.State.TERMINATED){
            Thread.sleep(100);
            state = thread.getState();
            System.out.println(state);
        }
    }
}

线程优先级

package com.xie.thread;

public class TestPriority {
    public static void main(String[] args) {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
        MyPriority myPriority = new MyPriority();
        Thread t1 = new Thread(myPriority);
        Thread t2 = new Thread(myPriority);
        Thread t3 = new Thread(myPriority);
        Thread t4 = new Thread(myPriority);

        t1.setPriority(3);
        t1.start();
        t2.setPriority(Thread.NORM_PRIORITY);
        t2.start();
        t3.setPriority(Thread.MAX_PRIORITY);
        t3.start();
        t4.setPriority(Thread.MIN_PRIORITY);
        t4.start();
    }
}

class MyPriority implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
    }
}

守护线程（daemon）

线程分为用户线程和守护线程
虚拟机必须确保用户线程执行完毕
虚拟机不用等待守护线程执行完毕，如后台记录操作日志，监控内存，垃圾回收等待

package com.xie.thread;

public class TestDaemon {
    public static void main(String[] args) {
        God god = new God();
        SomeOne someOne = new SomeOne();
        Thread thread = new Thread(god);
        thread.setDaemon(true);//默认false为用户线程，true改为守护线程
        thread.start();//上帝守护线程启动
        new Thread(someOne).start();
    }
}

class God implements Runnable{
    @Override
    public void run() {
        while (true){
            System.out.println("上帝守护者你");
        }
    }
}
class SomeOne implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 365; i++) {
            System.out.println("开心的活着。。");
        }
        System.out.println("------goodbye world!!!!!");
    }
}

线程同步

三大不安全案例

package com.xie.thread;

public class UnsafeBuyTicket {
    public static void main(String[] args) {
        BuyTicket buyTicket = new BuyTicket();
        new Thread(buyTicket,"aa").start();
        new Thread(buyTicket,"bb").start();
        new Thread(buyTicket,"cc").start();
    }
}

class BuyTicket implements Runnable{
    private int ticketNums = 10;
    boolean flag = true;
    @Override
    public void run() {
        while (flag){
            try {
                bug();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    private void bug() throws InterruptedException {
        if(ticketNums<=0){
            flag = false;
            return;
        }
        Thread.sleep(100);//模拟延时
        System.out.println(Thread.currentThread().getName()+"拿到票"+ticketNums--);
    }
}

package com.xie.thread;

import com.xie.oop.demo03.A;

public class UnsafeBank {
    public static void main(String[] args) {
        Account account = new Account(100,"结婚用");
        Drawing you = new Drawing(account,50,"you");
        Drawing girlFriend = new Drawing(account,100,"girlFriend");
        you.start();
        girlFriend.start();
    }
}
class Account{
    int money;
    String name;

    public Account(int money, String name) {
        this.money = money;
        this.name = name;
    }
}

class Drawing extends Thread{
    Account account;
    int drawingMoney;//要取的钱数
    int nowMoney;//手里的钱数

    public Drawing(Account account, int drawingMoney, String name) {
        super(name);
        this.account = account;
        this.drawingMoney = drawingMoney;
    }

    @Override
    public void run() {
        //判断还有没有钱
        if(account.money-drawingMoney<0){
            System.out.println("钱不够，取不了");
            return;
        }
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //卡内余额
        account.money = account.money - drawingMoney;
        //手里的钱
        nowMoney = nowMoney + drawingMoney;
        System.out.println(account.name+"余额为："+account.money);
        //Thread.currentThread().getName()=this.getName()
        System.out.println(this.getName()+"手里的钱为："+nowMoney);
    }
}

package com.xie.thread;

import java.util.ArrayList;
import java.util.List;
//不同线程操作同一个内存位置覆盖，导致实际大小小于期望大小
public class UnsafeList {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        for (int i = 0; i < 1000; i++) {
            new Thread(()->{
                list.add(Thread.currentThread().getName());
            }).start();
        }
        System.out.println(list.size());
    }
}

同步方法及同步块

package com.xie.thread;

public class UnsafeBuyTicket {
    public static void main(String[] args) {
        BuyTicket buyTicket = new BuyTicket();
        new Thread(buyTicket,"aa").start();
        new Thread(buyTicket,"bb").start();
        new Thread(buyTicket,"cc").start();
    }
}

class BuyTicket implements Runnable{
    private int ticketNums = 10;
    boolean flag = true;
    @Override
    public void run() {
        while (flag){
            try {
                bug();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    private synchronized void bug() throws InterruptedException {
        if(ticketNums<=0){
            flag = false;
            return;
        }
        Thread.sleep(100);//模拟延时
        System.out.println(Thread.currentThread().getName()+"拿到票"+ticketNums--);
    }
}

package com.xie.thread;

import com.xie.oop.demo03.A;

public class UnsafeBank {
    public static void main(String[] args) {
        Account account = new Account(100,"结婚用");
        Drawing you = new Drawing(account,50,"you");
        Drawing girlFriend = new Drawing(account,100,"girlFriend");
        you.start();
        girlFriend.start();
    }
}
class Account{
    int money;
    String name;

    public Account(int money, String name) {
        this.money = money;
        this.name = name;
    }
}

class Drawing extends Thread{
    Account account;
    int drawingMoney;//要取的钱数
    int nowMoney;//手里的钱数

    public Drawing(Account account, int drawingMoney, String name) {
        super(name);
        this.account = account;
        this.drawingMoney = drawingMoney;
    }

    @Override
    public void run() {
        synchronized (account){
            //判断还有没有钱
            if(account.money-drawingMoney<0){
                System.out.println("钱不够，取不了");
                return;
            }
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //卡内余额
            account.money = account.money - drawingMoney;
            //手里的钱
            nowMoney = nowMoney + drawingMoney;
            System.out.println(account.name+"余额为："+account.money);
            //Thread.currentThread().getName()=this.getName()
            System.out.println(this.getName()+"手里的钱为："+nowMoney);
        }
    }
}

package com.xie.thread;

import java.util.ArrayList;
import java.util.List;

public class UnsafeList {
    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        for (int i = 0; i < 1000; i++) {
            new Thread(()->{
                synchronized (list){
                    list.add(Thread.currentThread().getName());
                }
            }).start();
        }
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(list.size());
    }
}

CopyOnWriteArrayList

package com.xie.thread;

import java.util.concurrent.CopyOnWriteArrayList;
//测试JUC安全类型的集合
public class TestJUC {
    public static void main(String[] args) throws InterruptedException {
        CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
        for (int i = 0; i < 100; i++) {
            new Thread(()->{
                list.add(Thread.currentThread().getName());
            }).start();
        }
        Thread.sleep(100);
        System.out.println(list.size());
    }
}

死锁

package com.xie.thread;
//死锁：多个线程互相抱着对方需要的资源，形成僵持
public class DeadLock {
    public static void main(String[] args) {
        Makeup makeup1 = new Makeup(0,"li");
        Makeup makeup2 = new Makeup(1,"wang");
        makeup1.start();
        makeup2.start();
    }
}
//口红
class Lipstick{}
//镜子
class Mirror{}
//化妆
class Makeup extends Thread{
    //资源只有一份所以用static来保证
    static Lipstick lipstick = new Lipstick();
    static Mirror mirror = new Mirror();
    int chioce;
    String name;

    public Makeup(int chioce, String name) {
        this.chioce = chioce;
        this.name = name;
    }

    @Override
    public void run() {
        try {
            makeup();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    private void makeup() throws InterruptedException {
        if(chioce==0){
            synchronized (lipstick){
                System.out.println(this.name+"获得了口红的锁");
                Thread.sleep(1000);
                synchronized (mirror){
                    System.out.println(this.name+"获得了镜子的锁");
                }
            }
            //将mirror的锁拿出来，这样就不会死锁
//            synchronized (mirror){
//                System.out.println(this.name+"获得了镜子的锁");
//            }
        }else {
            synchronized (mirror){
                System.out.println(this.name+"获得了镜子的锁");
                Thread.sleep(1000);
                synchronized (lipstick){
                    System.out.println(this.name+"获得了口红的锁");
                }
            }
        }
    }
}

Lock锁

package com.xie.thread;

import java.util.concurrent.locks.ReentrantLock;

public class TestLock {
    public static void main(String[] args) {
        TestLock2 testLock2 = new TestLock2();
        new Thread(testLock2).start();
        new Thread(testLock2).start();
        new Thread(testLock2).start();
    }
}

class TestLock2 implements Runnable{
    int ticketNums = 10;
    //定义lock锁
    private final ReentrantLock lock = new ReentrantLock();
    @Override
    public void run() {
        while (true){
            try{
                lock.lock();
                if(ticketNums>0){
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(ticketNums--);
                }else {
                    break;
                }
            } finally {
                lock.unlock();
            }
        }
    }
}

synchronized与Lock的对比

线程通信方法

管程法

package com.xie.thread;
//生产者、消费者、缓冲区、产品
public class TestPC {
    public static void main(String[] args) throws InterruptedException {
        SynContainer container = new SynContainer();
        new Productor(container).start();
        new Consumer(container).start();
    }
}
//生成者
class Productor extends Thread{
    SynContainer container;
    public Productor(SynContainer container) {
        this.container = container;
    }

    @Override
    public void run() {
        for (int i = 0; i < 30; i++) {
            try {
                container.push(new Chicken(i));
                System.out.println("生产了"+i+"只鸡");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}
//消费者
class Consumer extends Thread{
    SynContainer container;

    public Consumer(SynContainer container) {
        this.container = container;
    }

    @Override
    public void run() {
        for (int i = 0; i < 30; i++) {
            try {
                Chicken chicken = container.pop();
                System.out.println("消费了"+chicken.id+"只鸡");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}
//产品
class Chicken{
    int id;
    public Chicken(int id) {
        this.id = id;
    }
}
//缓冲区
class SynContainer{
    Chicken[] chickens = new Chicken[10];
    int count = 0;
    //生产
    public synchronized void push(Chicken chicken) throws InterruptedException {
        //如果容器满了，则等待消费
        if(count == chickens.length){
            this.wait();
        }
        //如果没有满，则生产
        chickens[count] = chicken;
        count++;
        //生产后可以通知消费
        this.notifyAll();
    }
    //消费
    public synchronized Chicken pop() throws InterruptedException {
        //如果没有产品，则等待生产
        if(count == 0){
            this.wait();
        }
        //有产品，则消费
        count--;
        Chicken chicken = chickens[count];
        //消费后，通知生产
        this.notifyAll();
        return chicken;
    }
}

信号灯法

package com.xie.thread;

public class TestPC2 {
    public static void main(String[] args) {
        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;
    }

    @Override
    public void run() {
        for (int i = 0; i < 10; i++) {
            if(i%2==0){
                tv.play("快乐大本营");
            }else {
                tv.play("抖音美好生活");
            }
        }
    }
}
//消费者-->观众
class Watcher extends Thread{
    TV tv;

    public Watcher(TV tv) {
        this.tv = tv;
    }

    @Override
    public void run() {
        for (int i = 0; i < 10; i++) {
            tv.watch();
        }
    }
}
//产品-->节目
class TV{
    String voice;//表演的节目
    boolean flag = true;
    //表演
    public synchronized void play(String voice){
        if(!flag){
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("演员表演了："+voice);
        //表演后通知观看
        this.voice = voice;
        this.flag = !this.flag;
        this.notifyAll();
    }
    //观看
    public synchronized void watch(){
        if(flag){
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        //观看后通知表演
        System.out.println("观众观看："+this.voice);
        this.flag = !this.flag;
        this.notifyAll();
    }
}

线程池

package com.xie.thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TestPool {
    public static void main(String[] args) {
        //创建服务，创建线程池
        //newFixedThreadPool参数为线程池大小
        ExecutorService service = Executors.newFixedThreadPool(5);
        //执行，Runnable接口实现类
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        //关闭连接
        service.shutdown();
    }
}
class MyThread implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName());
    }
}

posted @ 2022-04-30 11:38 少年阿川阅读(25) 评论(0) 收藏举报

刷新页面返回顶部

xiexieyc

第十五话-Java线程

Thread类

网图下载案例

Runnable接口

线程并发问题

模拟龟兔赛跑

Callable接口

静态代理模式

Lamda表达式

线程五大状态

线程五大状态

线程方法

停止线程

线程休眠-sleep

线程礼让-yield

线程强制执行-join

观察线程状态

线程优先级

守护线程（daemon）

线程同步

三大不安全案例

同步方法及同步块

CopyOnWriteArrayList

死锁

Lock锁

synchronized与Lock的对比

线程通信方法

管程法

信号灯法

线程池

公告