Java多线程

进程与线程的理解

多线程的实现

  • Thread类–继承
  • Runable接口–实现
  • Callable接口–实现

Thread类

  • 建立一个线程对像
  • 开启多线程
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public class threadstest extends Thread{
    //    有两种创建线程的方法
    //    第一种就是通过继承 Thread 然后重写run的方法
    @Override
    public void run(){
        for (int i = 0; i<100; i++){
            System.out.println("这里是多线程----------------run");
        }
    }

    public static void main(String[] args) {
//        建立一个多线程中的实例
        threadstest thread = new threadstest();
//        开启多线程
        thread.start();

        for (int i = 0; i<1000; i++){
            System.out.println("这里是主线程");
        }
    }

Runnable 接口—实现

  • 创建一个线程
  • 通过线程创建一个线程对象，这里使用代理
  • 利用线程对象启动多线程
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package TestFile.ThreadTest;

public class RunableTest implements Runnable{
    @Override
    public void run(){
        for (int i = 0; i < 100; i++) {
            System.out.println("这是一个子线程-----------");
        }
    }

    public static void main(String[] args) {
//        创建一个线程
        RunableTest p1 = new RunableTest();
        RunableTest p2 = new RunableTest();
//        通过线程对象，开启线程-------代理
        Thread thread1 = new Thread(p1);
        Thread thread2 = new Thread(p2);
//        多线程
        thread1.start();
        thread2.start();

        for (int i = 0; i < 1000; i++) {
            System.out.println("这是主线程");
        }
    }
}

多线程操作一个对象–Runnable接口实现

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// 多个线程抢票
public class multiThreadandOneSource implements Runnable {
    // 票数
    private int ticketNums = 10;

    @Override
    public void run() {
        while (true){
            if (ticketNums<=0){
                break;
            }

            System.out.println(Thread.currentThread().getName()+"-->抢到了第"+ticketNums--+"张票");
        }

    }

    public static void main(String[] args) {
        multiThreadandOneSource ticket = new multiThreadandOneSource();
        try {
            Thread.sleep(200);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
//        定义多个线程
        new Thread(ticket, "学生").start();
        new Thread(ticket, "老师").start();
        new Thread(ticket, "黄牛").start();
        new Thread(ticket, "老板").start();

    }
}
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// 模拟龟兔赛跑
// 这里也是多个线程用同一个对象
public class turtleRabbitGame implements Runnable{
    private int distance = 100;
    private static String winner;

    @Override
    public void run() {
        while (true){
            boolean flag = gameOver(distance);
            if (flag){
                break;
            }
            if (Thread.currentThread().getName().equals("兔子")){
                try {
                    Thread.sleep(300);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            distance--;
        }
    }

    public boolean gameOver(int steps){
        if (winner!=null){
            return true;
        } else{
            if (steps<=0){
                winner = Thread.currentThread().getName();
                System.out.println("winner is "+ winner);
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
//        建立同一个资源
        turtleRabbitGame race = new turtleRabbitGame();

        new Thread(race, "兔子").start();
        new Thread(race, "乌龟").start();



//        turtleRabbitGame turtle = new turtleRabbitGame();
//        turtleRabbitGame rabbit = new turtleRabbitGame();
//
//        Thread turtleThread = new Thread(turtle, "乌龟");
//        Thread rabbitThread = new Thread(rabbit, "兔子");
//        turtleThread.start();
//        try {
//            Thread.sleep(200);
//        } catch (InterruptedException e) {
//            e.printStackTrace();
//        }
//        rabbitThread.start();
    }
}