（Java多线程系列一）快速入门

Java多线程快速入门

1、线程和进程的区别

2、多线程的应用场景

3、多线程的创建方式

（1）继承Thread类，重写run()方法

class ThreadDemo extends Thread {

    @Override

    public void run() {

        System.out.println("这里是子线程");

        System.out.println("线程名称：" + this.getName());

        System.out.println("线程ID：" + this.getId());

    }

}

public class JavaThreadDemo01 {

    public static void main(String[] args) {

        System.out.println("这里是主线程");

        ThreadDemo threadDemo = new ThreadDemo();

        threadDemo.start();

    }

}

(2)实现Runnable接口，重写run()方法

class RunnableDemo implements Runnable {

    @Override

    public void run() {

        System.out.println("这里是子线程");

        System.out.println("线程名称：" + Thread.currentThread().getName());

        System.out.println("线程ID：" + Thread.currentThread().getId());

    }

}

public class JavaThreadDemo02 {

    public static void main(String[] args) {

        System.out.println("这里是主线程");

        RunnableDemo runnableDemo = new RunnableDemo();

        Thread thread = new Thread(runnableDemo);

        thread.start();

    }

}

(3)使用匿名内部类方式

public class JavaThreadDemo03 {

    public static void main(String[] args) {

        System.out.println("主线程");

        // 使用实现接口的方式

        Thread thread1 = new Thread(new Runnable() {

            @Override

            public void run() {

                System.out.println("这里是子线程");

                System.out.println("线程名称：" + Thread.currentThread().getName());

                System.out.println("线程ID：" + Thread.currentThread().getId());

            }

        });

        thread1.start();

        // 使用lambda表达式

        Thread thread2 = new Thread(() -> {

            System.out.println("这里是子线程");

            System.out.println("线程名称：" + Thread.currentThread().getName());

            System.out.println("线程ID：" + Thread.currentThread().getId());

        });

        thread2.start();

    }

}

(4)使用继承Thread类还是使用实现Runnable接口的方式新建线程好？

(5)启动线程调用start()方法还是run()方法？

4、多线程运行状态

5、判断线程的存活状态

源码地址