标签：Thread void System println new 多线程 public

多线程

Thread

package lesson01;

//创建线程的方式一：继承Thread类，重写run()方法，调用start开启线程
//线程开启不一定立即执行，有CPU调度执行
public class TestThread extends Thread{
    @Override
    public void run() {
        super.run();//run方法线程体
        for (int i = 0; i < 200; i++) {
            System.out.println("我在学习"+i);
        }
    }

    public static void main(String[] args) {
            //main线程，主线程
        //创建一个线程对象
        TestThread testThread = new TestThread();
        //调用start方法开启线程
        testThread.start();
        for (int i = 0; i < 1000; i++) {
            System.out.println("我在学习多线程"+i);
        }
    }
}

Runnable

package lesson01;

//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 < 200; i++) {
            System.out.println("我在学习"+i);
        }
    }

    public static void main(String[] args) {
        //main线程，主线程
        //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线程
//        Thread thread = new Thread(testThread3);
//        thread.start();
        new Thread(testThread3).start();
        for (int i = 0; i < 1000; i++) {
            System.out.println("我在学习多线程"+i);
        }
    }
}

初识并发问题

package lesson01;

//多个线程同时操作同一个对象
//买火车票的
//发现问题：多个线程操作一个资源的情况下，线程不安全，数据紊乱
public class TestThread4 implements Runnable{
    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--+"票");
        }
    }

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

龟兔赛跑

package lesson01;

public class Race implements Runnable{
    //胜利者
    private static String winner;
    @Override
    public void run() {
        for (int i = 0; i <= 100; i++) {
            //5模拟兔子睡觉
            if(Thread.currentThread().getName().equals("兔子")&& i%10==0){
                try {
                    Thread.sleep(2);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //1判断比赛是否结束
            boolean flag = gameOver(i);
            //2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");
        }
    }
    //3判断是否完成比赛
    private boolean gameOver(int steps){
        //4判断是否有胜利者
        if(winner!=null){//已经存在胜利者
            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();
    }
}

静态代理

package lesson2;

//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
public class StacticProxy {
    public static void main(String[] args) {
        You you = new You();
        new Thread(()-> System.out.println("love you")).start();
        new WeddingCompany(new You()).HappyMarry();
    }
}

interface Marry{
    void HappyMarry();
}

//真实角色
class You implements Marry{
    @Override
    public void HappyMarry() {
        System.out.println("结婚了");
    }
}

//代理角色,帮助你结婚
class WeddingCompany implements Marry{
    //代理真实角色
    private Marry target;

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

    @Override
    public void HappyMarry() {
        before();
        this.target.HappyMarry();
        after();
    }

    private void after() {
        System.out.println("收尾款");
    }

    private void before() {
        System.out.println("结婚之前布置现场");
    }
}

推到lambad表达式

package lesson2;

//推到lambda表达式
public class TestLambda1 {
    //3.静态内部类
    static class Like2 implements ILike{
        @Override
        public void lambad() {
            System.out.println("I like lambda2");
        }
    }
    public static void main(String[] args) {
        ILike like = new Like();
        like.lambad();

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

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

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

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

    }
}

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

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

简化 lambda 表达式

package lesson2;

public class TestLambda2 {

    public static void main(String[] args) {
        ILove love =null;
        /*ILove love = (int a)-> {
                System.out.println("Love You ->"+a);
            };
        //简化1 去掉参数类型
        love = (a)-> {
            System.out.println("Love You ->"+a);
        };*/
        //简化2 去掉括号
        love = (a,b)-> {
            System.out.println("Love You ->"+a);
            System.out.println(234);
        };
        //简化3 去掉花括号
        love =(a,b)-> System.out.println("Love You ->"+a+b);
        love.love(521,502);
    }
    //lambda表达式只能有一行代码的情况下才能简化成一行，如果有多行，就用代码块包裹
    //前提是接口必须是函数式接口
    //多个参数也可以去掉参数类型，要去掉就都去掉，必须加括号；
}

interface ILove{
    void love(int a,int b);
}

Callable方法

package lesson2;

import org.apache.commons.io.FileUtils;

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

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;
    }
    //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("下载了文件名："+name);
        return true;
    }

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        TestCallable t1 = new TestCallable("/i/l/?n=24&i=blog/3477492/202407/3477492-20240731143701587-893341756.png","1.png");
        TestCallable t2 = new TestCallable("/i/l/?n=24&i=blog/3477492/202407/3477492-20240731143701581-272578577.png","2.png");
        TestCallable t3 = new TestCallable("/i/l/?n=24&i=blog/3477492/202407/3477492-20240731143701879-1214671590.png","3.png");
        //创建执行服务
        ExecutorService ser = Executors.newFixedThreadPool(3);
        //提交服务
        Future<Boolean> r1 = ser.submit(t1);
        Future<Boolean> r2 = ser.submit(t2);
        Future<Boolean> r3 = ser.submit(t3);
        //获取结果
        boolean rs1 = r1.get();
        boolean rs2 = r2.get();
        boolean rs3 = r3.get();
        System.out.println(rs1);
        System.out.println(rs2);
        System.out.println(rs3);
        //关闭服务
        ser.shutdown();
    }
}
//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");
        }
    }
}

线程停止

package lesson2;

//测试stop
//1.建议线程正常停止，-->利用次数，不建议死循环
//2.建议标志位，-->设置一个标志位
//3.不要使用stop或者destory等过时的或者JDK不建议使用的方法
public class TestStop implements Runnable{
    //1.设置一个标志位
   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 < 1000; i++) {
            System.out.println("mian"+i);
            if(i==900){
                //调用stop方法切换标志位，让线程停止
                testStop.stop();
                System.out.println("线程停止了");
            }
        }
    }
}

线程休眠 sleep

package lesson2;

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());//获取系统当前时间
        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;
            }
        }
    }
}

join 插队

package lesson2;

//测试join方法，插队
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 {
        //启动线程
        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("mian"+i);
        }
    }
}

观察线程的五大状态

新生->就绪->运行->阻塞->死亡

package lesson2;

//观察线程的启动状态
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新生状态

        //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，就一直输出状态
            Thread.sleep(100);
            state=thread.getState();//更新状态
            System.out.println(state);//输出状态
        }
    }
}

测试线程的优先级

package lesson03;

//测试线程的优先级
public class TestPriority {
    public static void main(String[] args) {
        //主线程的默认优先级
        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);

        //先设置优先级，再启动
        t1.start();
        t2.setPriority(2);
        t2.start();

        t3.setPriority(6);
        t3.start();

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

        t5.start();
    }
}

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

守护线程

package lesson03;

//测试守护线程
public class TestDemon {
    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表示用户线程，正常的线程都是用户线程
        thread.start();//守护线程启动
        new Thread(you).start();//用户线程启动


    }
}

//上帝
class God implements Runnable{
    @Override
    public void run() {
        while (true) {
            System.out.println("上帝保佑着你");
        }
    }
}

//你
class You implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 36500; i++) {
            System.out.println("你一生都开心的活着");
        }
        System.out.println("goodbye world!");
    }
}

多线程的不安全案例

package lesson04;


//不安全的取钱
public class UnSafeBank {
    public static void main(String[] args) {
        //账户
        Account account = new Account(100,"金额");
        Drawing you = new Drawing(account,50,"你");
        Drawing girlFrend = new Drawing(account,100,"girlFrend");

        you.start();
        girlFrend.start();
    }
}

//账户
class Account{
    int money;//余额
    String name;//卡名
    public Account(int money,String name){
        this.money= money;
        this.name=name;
    }
}

//模拟取款
class Drawing extends Thread{
    Account account;//账户
    int drawingMoney;//取了多少钱
    int nowMoney;//现在手里还有多少钱
    public Drawing(Account account,int drawingMoney,String name){
        super(name);
        this.account=account;
        this.drawingMoney = drawingMoney;
    }

    //取钱
    @Override
    public void run() {
        //判断有没有钱
        if(account.money-drawingMoney<0){
            System.out.println(Thread.currentThread().getName()+"钱不够，取不了");
            return;
        }
        //sleep 可以放大问题的发生性
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        account.money=account.money-drawingMoney;//卡内余额 = 余额-取得钱
        nowMoney=nowMoney+drawingMoney;//手里的钱
        System.out.println(account.money+"余额为："+account.money);
        System.out.println(this.getName()+"手里的钱"+nowMoney);
    }
}

package lesson04;

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) throws InterruptedException {
        List<String> list =new ArrayList<String>();
        for (int i = 0; i < 1000; i++) {
            new Thread(()->{
                list.add(Thread.currentThread().getName());
            }).start();
        }
        Thread.sleep(1000);
        System.out.println(list.size());
    }
}

synchronized方法和synchronized方法块

package lesson01;

//多个线程同时操作同一个对象
//买火车票的
//发现问题：多个线程操作一个资源的情况下，线程不安全，数据紊乱
public class TestThread4 implements Runnable{
    private int ticketnums=10;
    @Override
    //synchronized针对的是增删改查的对象
    public synchronized 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--+"票");
        }
    }

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

package lesson04;


//不安全的取钱
public class UnSafeBank {
    public static void main(String[] args) {
        //账户
        Account account = new Account(100,"金额");
        Drawing you = new Drawing(account,50,"你");
        Drawing girlFrend = new Drawing(account,100,"girlFrend");

        you.start();
        girlFrend.start();
    }
}

//账户
class Account{
    int money;//余额
    String name;//卡名
    public Account(int money,String name){
        this.money= money;
        this.name=name;
    }
}

//模拟取款
class Drawing extends Thread{
    Account account;//账户
    int drawingMoney;//取了多少钱
    int nowMoney;//现在手里还有多少钱
    public Drawing(Account account,int drawingMoney,String name){
        super(name);
        this.account=account;
        this.drawingMoney = drawingMoney;
    }

    //取钱
    @Override
    public void run() {
        //synchronized默认锁的是this，锁的对象是变化的量
        synchronized (account){
            //判断有没有钱
            if(account.money-drawingMoney<0){
                System.out.println(Thread.currentThread().getName()+"钱不够，取不了");
                return;
            }
            //sleep 可以放大问题的发生性
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            account.money=account.money-drawingMoney;//卡内余额 = 余额-取得钱
            nowMoney=nowMoney+drawingMoney;//手里的钱
            System.out.println(account.money+"余额为："+account.money);
            System.out.println(this.getName()+"手里的钱"+nowMoney);

        }

    }
}

测试JUC安全类型的集合

package lesson04;

import java.util.concurrent.CopyOnWriteArrayList;

//测试JUC安全类型的集合
public class JUCDemo01 {
    public static void main(String[] args) {
        CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<String>();
        for (int i = 0; i < 1000; i++) {
            new Thread(()->{
                list.add(Thread.currentThread().getName());
            }).start();
        }
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(list.size());
    }
}

解决死锁的方法

package lesson04;

//死锁：多个线程相互有对方需要的资源，然后形成僵持
public class DeadLock {
    public static void main(String[] args) {
        Makeup g1 = new Makeup(0,"灰姑凉");
        Makeup g2 = new Makeup(1,"白雪公主");
        g1.start();
        g2.start();
    }

}

//口红
class Lipstick{

}

//镜子
class  Mirror{

}

//化妆
class Makeup extends Thread{
    //需要的资源只有一份,用static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() {
        try {
            makeup();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //化妆
    }
    //化妆，互相持有对方的锁，就是需要拿到对方的资源
    private void makeup() throws InterruptedException {
        if(choice==0){
            synchronized (lipstick){//获得口红的锁
                System.out.println(this.girlName+"获得口红的锁");
                Thread.sleep(1000);
            }
            synchronized (mirror){//一秒后获得镜子的锁
                System.out.println(this.girlName+"获得镜子的锁");
            }
        }else {
            synchronized (mirror){//获得口红的锁
                System.out.println(this.girlName+"获得镜子的锁");
                Thread.sleep(1000);
            }
            synchronized (lipstick){//一秒后获得镜子的锁
                System.out.println(this.girlName+"获得口红的锁");
            }
        }
    }
}

加锁和解锁

package lesson04;

import java.util.concurrent.locks.ReentrantLock;

//测试Lock
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();
            }

        }
    }
}

管程法

package lesson04;

//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();
    }
}

//产生者
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;
    }

    @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，生产者等待
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        //如果没有满，就需要放入产品
        chickens[count]=chicken;
        count++;
        //可以通知消费者消费
        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，利用标志位解决

package lesson04;

//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");
            }
        }
    }
}
//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 T
    //观众观看,演员等待 F
    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();
        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("观众观看了"+voice);
        //通知演员表演
        this.notifyAll();
        this.flag= !this.flag;
    }
}

线程池

package lesson04;

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
        //2.newFixedThreadPool参数为池子大小
        ExecutorService service = Executors.newFixedThreadPool(10);
        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());
    }
}

标签：Thread,void,System,println,new,多线程,public
From： https://www.cnblogs.com/huangjiangfei/p/18343799

多线程

多线程

Thread

Runnable

静态代理

推到lambad表达式

简化 lambda 表达式

Callable方法

线程停止

线程休眠 sleep

join 插队

观察线程的五大状态

测试线程的优先级

守护线程

多线程的不安全案例

synchronized方法和synchronized方法块

测试JUC安全类型的集合

解决死锁的方法

加锁和解锁

管程法

信号灯法，利用标志位解决

线程池

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