多线程

创建线程方式一：继承Thread类，重写run()方法，调用start开启线程

public class TestThread1 extends Thread {

    @Override
    public void run() {
        //run方法线程体
        for (int i = 0; i < 200; i++) {
            System.out.println("我在看代码---"+i);
        }
    }

    public static void main(String[] args) {
        //main线程，主线程

        //创建一个线程对象
        TestThread1 testThread1 = new TestThread1();


        //调用start()方法开启线程
        testThread1.start();

        for (int i = 0; i < 1000; i++) {
            System.out.println("我在学习多线程---"+i);
        }
    }
}

总结：注意，线程开启不一定立即执行，由CPU调度执行

案例：下载图片

package com.kuang.demo01;

import org.apache.commons.io.FileUtils;

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

//练习Thread,实现多线程同步下载图片
public class TestThread2 extends Thread{

    private String url;
    private String name;

    public TestThread2(String url,String name){
        this.url = url;
        this.name = name;
    }


    //下载图片线程的执行体
    @Override
    public void run() {
        WebDownloader webDownloader = new WebDownloader();
        webDownloader.downloader(url,name);
        System.out.println("下载的文件名为："+name);
    }

    public static void main(String[] args) {
        TestThread2 testThread2 = new TestThread2("https://t7.baidu.com/it/u=1595072465,3644073269&fm=193&f=GIF","2.jpg");

        testThread2.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");
        }
    }
}

创建线程方式2：实现runnable接口，重写run方法，执行线程需要丢入runnable接口实现类，调用start方法

package com.kuang.demo01;


//创建线程方式2：实现runnable接口，重写run方法，执行线程需要丢入runnable接口实现类，调用start方法
public class TestThread3 implements Runnable{

    @Override
    public void run() {
        //run方法线程体
        for (int i = 0; i < 20; i++) {
            System.out.println("多线程方法---"+i);
        }
    }

    public static void main(String[] args) {
        //创建runnable接口的实现类对象
        TestThread3 testThread3 = new TestThread3();
        //创建线程对象，通过线程对象来开启我们的线程代理。
        Thread thread = new Thread(testThread3);
        thread.start();

        for (int i = 0; i < 20; i++) {
            System.out.println("我在学习多线程---"+i);
        }
    }
}

多线程并发问题

package com.kuang.demo01;

//多个线程同时操作同一个对象
//买火车票的例子

//发现问题：多个线程操作同一个资源的情况下，线程不安全，数据混乱。
public class TestThread4 implements Runnable{

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

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

案例：龟兔赛跑

package com.kuang.demo01;

//模拟龟兔赛跑
public class Race implements Runnable{

    //胜利者
    private static String winner;

    @Override
    public void run() {
        for (int i = 0; i <= 100; i++) {

            //模拟兔子休息
            if(Thread.currentThread().getName().equals("兔子")&& i%10==0){
                try {
                    Thread.sleep(1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //判断比赛是否结束
            boolean flag = gameOver(i);
            //如果比赛结束了，就停止程序
            if(flag){
                break;
            }

            System.out.println(Thread.currentThread().getName()+"跑了"+i+"步");
        }
    }

    //判断是否完成比赛
    private boolean gameOver(int steps){
        //判断是否有胜利者
        if(winner != null){
            return true;
        }{
            if(steps >= 100){
                winner = Thread.currentThread().getName();
                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();
    }
}

线程创建方式三：实现callable接口

package com.kuang.demo02;

import com.kuang.demo01.TestThread2;
import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.concurrent.*;

//线程创建方式三：实现callable接口
public class TestCallable implements Callable<Boolean> {

    private String url;
    private String name;

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


    //下载图片线程的执行体
    @Override
    public Boolean call() {
        WebDownloader webDownloader = new WebDownloader();
        webDownloader.downloader(url,name);
        System.out.println("下载的文件名为："+name);
        return true;
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        TestCallable testCallable = new TestCallable("https://t7.baidu.com/it/u=1595072465,3644073269&fm=193&f=GIF","2.jpg");

        //创建执行服务：
        ExecutorService ser = Executors.newFixedThreadPool(1);

        //提交执行
        Future<Boolean> r1 = ser.submit(testCallable);

        //获取结果
        boolean rs1 = r1.get();

        //关闭服务
        ser.shutdownNow();
    }
}


//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");
        }
    }
}

lambda表达式

package com.kuang.lambda;

/*
* 推导lambda表达式
* */
public class TestLambda1 {

    //3.静态内部类
    static class Like2 implements ILike{
        @Override
        public void lambda() {
            System.out.println("i like lambda2");
        }
    }

    public static void main(String[] args) {
        ILike like = new Like();
        like.lambda();

        like = new Like2();
        like.lambda();

        //4.局部内部类
        class Like3 implements ILike{
            @Override
            public void lambda() {
                System.out.println("i like lambda3");
            }
        }

        like = new Like3();
        like.lambda();

        //5.匿名内部类。没有类的名称，必须借助接口或者父类
        like = new ILike() {
            @Override
            public void lambda() {
                System.out.println("i like lambda4");
            }
        };
        like.lambda();

        //6.用lambda简化
        like = ()->{
            System.out.println("i like lambda5");
        };
        like.lambda();
    }
}

//1.定义一个函数式接口
interface ILike{
    void lambda();
}

//2.实现类
class Like implements ILike{
    @Override
    public void lambda() {
        System.out.println("i like lambda");
    }
}

//总结：
    //lambda表达式只能有一行代码的情况下才能简化成为一行，如果有多行，那就用代码块包裹。
    //前提是接口为函数式接口
    //多个参数也可以去掉参数类型，要去掉就都去掉

线程停止

package com.kuang.state;

//测试stop
//1.建议线程正常停止--->，不建议死循环
//2.建议使用标志位--->设置一个标志位
//3.不要使用stop或者destroy等过时或者JDK不建议使用的方法

public class TestStop implements Runnable{

    //1.设置一个标识位
    private boolean flag = true;

    @Override
    public void run() {
        int i = 0;
        while(flag){
            System.out.println("run....Thread"+i++);
        }
    }

    //2.设置一个公开的方法停止线程，转换标志位
    public void stop(){
        this.flag = false;
    }

    public static void main(String[] args) {
        TestStop testStop = new TestStop();
        new Thread(testStop).start();

        for (int i = 0; i < 300; i++) {
            System.out.println("main"+i);
            if(i==150){
                //调用stop方法切换标志位，让线程停止
                testStop.stop();
                System.out.println("线程停止");
            }
        }
    }
}

线程休眠

package com.kuang.state;

import java.text.SimpleDateFormat;
import java.util.Date;

//模拟倒计时
public class TestSleep2 {

    public static void main(String[] args) {
        //打印当前系统时间
        Date startTime = new Date(System.currentTimeMillis());//获得系统当前的时间
        while(true){
            try {
                Thread.sleep(1000);
                System.out.println(new SimpleDateFormat("HH:mm:ss").format(startTime));
                startTime = new Date(System.currentTimeMillis());//更新当前时间
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    //模拟倒计时
    public static void tenDown() throws InterruptedException {
        int num = 10;
        while(true){
            Thread.sleep(1000);
            System.out.println(num--);
            if(num<=0){
                break;
            }
        }
    }
}

线程礼让

package com.kuang.state;


//测试线程礼让
//礼让不一定成功，看CPU心情
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();
        System.out.println(Thread.currentThread().getName()+"线程停止执行");
    }
}

线程强制执行

package com.kuang.state;

//测试join方法，想象为插队
public class TestJoin implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            System.out.println("vip通道"+i);
        }
    }

    public static void main(String[] args) throws InterruptedException {

        //启动我们的线程
        TestJoin testJoin = new TestJoin();
        Thread thread = new Thread(testJoin);
        thread.start();

        //主线程
        for (int i = 0; i < 1000; i++) {
            if(i==200){
                thread.join();
            }
            System.out.println("main线程"+i);
        }
    }
}

线程状态

package com.kuang.state;

public class TestState {

    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(()->{
            for (int i = 0; i < 5; i++) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("/////");
        });

        //观察状态
        Thread.State state = thread.getState();
        System.out.println(state);//NEW


        //观察启动后
        thread.start();//启动线程
        state = thread.getState();
        System.out.println(state);//Run

        while (state != Thread.State.TERMINATED){//只要线程不终止。就一致输出状态
            Thread.sleep(100);
            state = thread.getState();//更新线程状态
            System.out.println(state);//输出状态
        }
    }
}

线程优先级

package com.kuang.state;

//测试线程优先级
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);
        Thread t5 = new Thread(myPriority);
        Thread t6 = new Thread(myPriority);

        //先设置优先级，再启动
        t1.start();

        t2.setPriority(1);
        t2.start();

        t3.setPriority(4);
        t3.start();

        t4.setPriority(Thread.MAX_PRIORITY);
        t4.start();
        
    }

}


class MyPriority implements Runnable{

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

守护（daemon）线程

package com.kuang.state;


//测试守护线程
//上帝守护你
public class TestDaemon {
    public static void main(String[] args) {
        God god = new God();
        You you = new You();

        Thread thread = new Thread(god);
        thread.setDaemon(true);//默认false式用户线程，正常的线程都是用户线程...
        thread.start();//上帝守护线程启动

        new Thread(you).start();//你，用户线程启动
    }
}


//上帝
class God implements Runnable{
    @Override
    public void run() {
        System.out.println("上帝保佑者你");
    }
}


//你
class You implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 36500; i++) {
            System.out.println("开心每一天");
        }
        System.out.println("game over");
    }
}

线程同步机制

三大不安全实例

买票

package com.kuang.syn;

//不安全的买票
public class UnsafeBuyTicket {
    public static void main(String[] args) {
        BuyTicket buyTicket = new BuyTicket();
        new Thread(buyTicket,"小明").start();
        new Thread(buyTicket,"小红").start();
        new Thread(buyTicket,"小刚").start();
    }
}


class BuyTicket implements Runnable{

    //票数
    private int ticket = 10;
    boolean flag = true;

    //买票
    @Override
    public void run() {
        while(flag){
            try {
                buy();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    //synchronized 同步方法，锁的是this
    private void buy() throws InterruptedException {
        if(ticket<=0){
            flag = false;
            return;
        }
        Thread.sleep(100);
        System.out.println(Thread.currentThread().getName()+"购买第"+ticket--+"张票");
    }
}

银行取钱

package com.kuang.syn;

//不安全的取钱
public class UnsafeBank {
    public static void main(String[] args) {
        //账户
        Bank bank = new Bank(1000,"结婚基金");
        Drawing you = new Drawing(bank,50,"你");
        Drawing girlfriend = new Drawing(bank,100,"girlfriend");

        you.start();
        girlfriend.start();
    }
}


//账户
class Bank{
    int money;
    String name;

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


//取钱
class Drawing extends Thread{

    Bank bank;//账户
    //取了多少钱
    int drawingMoney;
    //现在手里有都少钱
    int nowMoney;

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


    //取钱
    @Override
    public void run() {
        //锁的对象就是变化的量，就是增删改的对象
       
            while (bank.money-drawingMoney<0){
                System.out.println(Thread.currentThread().getName()+"钱不够,取不了");
                break;
            }


            try {
                sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            //卡内余额 = 余额 - 你取的钱
            bank.money = bank.money - drawingMoney;
            //你手里的钱
            nowMoney = nowMoney + drawingMoney;

            System.out.println(bank.name+"余额为:"+bank.money);

            System.out.println(this.getName()+"手里的钱"+nowMoney);
        }
        

}

集合

package com.kuang.syn;


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

//线程不安全的集合
public class UnsafeList {
    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        for (int i = 0; i < 10000; i++) {
            new Thread(()->{
              
                    list.add(Thread.currentThread().getName());
              

            }).start();
        }
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(list.size());
    }
}

同步方法

package com.kuang.syn;

//不安全的买票
public class UnsafeBuyTicket {
    public static void main(String[] args) {
        BuyTicket buyTicket = new BuyTicket();
        new Thread(buyTicket,"小明").start();
        new Thread(buyTicket,"小红").start();
        new Thread(buyTicket,"小刚").start();
    }
}


class BuyTicket implements Runnable{

    //票数
    private int ticket = 10;
    boolean flag = true;

    //买票
    @Override
    public void run() {
        while(flag){
            try {
                buy();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    //synchronized 同步方法，锁的是this
    private synchronized void buy() throws InterruptedException {
        if(ticket<=0){
            flag = false;
            return;
        }
        Thread.sleep(100);
        System.out.println(Thread.currentThread().getName()+"购买第"+ticket--+"张票");
    }
}

package com.kuang.syn;

//不安全的取钱
public class UnsafeBank {
    public static void main(String[] args) {
        //账户
        Bank bank = new Bank(1000,"结婚基金");
        Drawing you = new Drawing(bank,50,"你");
        Drawing girlfriend = new Drawing(bank,100,"girlfriend");

        you.start();
        girlfriend.start();
    }
}


//账户
class Bank{
    int money;
    String name;

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


//取钱
class Drawing extends Thread{

    Bank bank;//账户
    //取了多少钱
    int drawingMoney;
    //现在手里有都少钱
    int nowMoney;

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


    //取钱
    @Override
    public void run() {
        //锁的对象就是变化的量，就是增删改的对象
        synchronized (bank){
            while (bank.money-drawingMoney<0){
                System.out.println(Thread.currentThread().getName()+"钱不够,取不了");
                break;
            }


            try {
                sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            //卡内余额 = 余额 - 你取的钱
            bank.money = bank.money - drawingMoney;
            //你手里的钱
            nowMoney = nowMoney + drawingMoney;

            System.out.println(bank.name+"余额为:"+bank.money);

            System.out.println(this.getName()+"手里的钱"+nowMoney);
        }
        }

}

package com.kuang.syn;


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

//线程不安全的集合
public class UnsafeList {
    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        for (int i = 0; i < 10000; i++) {
            new Thread(()->{
                synchronized (list){
                    list.add(Thread.currentThread().getName());
                }

            }).start();
        }
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(list.size());
    }
}

JUC(扩充)

package com.kuang.syn;


import java.util.concurrent.CopyOnWriteArrayList;

//测试JUC安全类型的集合
public class TestJUC {
    public static void main(String[] args) {
        CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<String>();
        for (int i = 0; i < 10000; i++) {
            new Thread(()->{
                list.add(Thread.currentThread().getName());
            }).start();
        }

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println(list.size());
    }
}

死锁

package com.kuang.thread;

//死锁：多个线程互相抱着对方需要的资源，然后形成僵持
public class DeadLock {
    public static void main(String[] args) {
        Makeup g1 = new Makeup(0,"灰姑娘");
        Makeup g2 = new Makeup(1, "白雪公主");

        g1.start();
        g2.start();
    }
}


//口红
class Lipstick{

}

//镜子
class  Mirror{

}

class Makeup extends Thread {

    //需要的资源只有一份，用static来保证只有一份
    static Lipstick lipstick = new Lipstick();
    static Mirror mirror = new Mirror();

    int choice;//选择
    String girlName; //使用化妆品的人

    Makeup(int choice, String girlName) {
        this.choice = choice;
        this.girlName = girlName;
    }

    @Override
    public void run() {
        //化妆
        try {
            makeup();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    //化妆
    private void makeup() throws InterruptedException {
        if (choice == 0) {
            synchronized (lipstick) {
                System.out.println(this.girlName + "获得口红的锁");
                Thread.sleep(1000);
                }
            synchronized (mirror) {
                System.out.println(this.girlName + "获得镜子的锁");
            }
        } else {
            synchronized (mirror) {
                System.out.println(this.girlName + "获得镜子的锁");
                Thread.sleep(2000);
                }
            synchronized (lipstick) {
                System.out.println(this.girlName + "获得口红的锁");
            }
        }
    }
}

lock锁

package com.kuang.gaoji;

import java.util.concurrent.locks.ReentrantLock;

//测试Lock锁
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();//加锁
                if(ticketNums>0){
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(ticketNums--);
                }else {
                    break;
                }
            }finally {
                //解锁
                lock.unlock();
            }

        }
    }
}

线程协作

管程法：

package com.kuang.gaoji;


//测试：生产者消费者模型-->利用缓冲区解决：管程法

//生产者，消费者，产品，缓冲区
public class TestPC {
    public static void main(String[] args) {
        SynContainer container = new SynContainer();
        new Productor(container).start();
        new Consumer(container).start();
    }
}

//生产者
class Productor extends Thread{
    SynContainer container;
    public Productor(SynContainer container){
        this.container = container;
    }

    //生产

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            container.push(new Chicken(i));
            System.out.println("生产了"+i+"只鸡");
        }
    }
}

//消费者
class Consumer extends Thread{
    SynContainer container;
    public Consumer(SynContainer container){
        this.container = container;
    }

    //消费

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            System.out.println ("消费了-->"+container.pop().id+"只鸡");
        }
    }
}

//产品
class Chicken{
    int id;//产品编号

    public Chicken(int id){
        this.id = id;
    }
}

//缓冲区
class SynContainer{

    //需要一个容器大小
    Chicken[] chickens = new Chicken[10];
    //容器计数器
    int count = 0;

    //生产者放入产品
    public synchronized void push(Chicken chicken){
        //如果容器满了，就需要等待消费者消费
        if (count == chickens.length){
            //通知消费者消费，生产等待
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        //如果没有满，我们就需要丢入产品
        chickens[count]=chicken;
        count++;

        //可以通知消费者消费了
        this.notifyAll();
    }

    //消费者消费产品
    public synchronized Chicken pop(){
        //判断能否消费
        if (count==0){
            //等待生产者生产，消费者等待
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        //如果可以消费
        count--;
        Chicken chicken = chickens[count];

        //吃完了，通知生产者生产
        this.notifyAll();
        return chicken;
    }
}

信号灯法：

package com.kuang.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) {
        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 < 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;
    }

    @Override
    public 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
    //观众观看，演员等待
    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);
        //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(){
        if (flag){
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("观看了:"+voice);
        //通知演员表演
        this.notifyAll();
        this.flag = !this.flag;
    }
}

线程池

package com.kuang.gaoji;


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

//测试线程池
public class TestPool {

    public static void main(String[] args) {
        //1.创建服务，创建线程池
        //newFixedThreadPool 参数为：线程池大小
        ExecutorService service = Executors.newFixedThreadPool(10);

        //执行
        service.execute(new Mythread());
        service.execute(new Mythread());
        service.execute(new Mythread());
        service.execute(new Mythread());

        //2.关闭连接
        service.shutdown();
    }


}

class Mythread implements Runnable{

    @Override
    public void run() {
            System.out.println(Thread.currentThread().getName());

    }
}

posted @ 2021-11-28 21:10 技术人员小饭阅读(29) 评论(0) 收藏举报

刷新页面返回顶部

技术人员小饭

多线程

多线程

公告