Java多线程的4种创建方法

Java多线程的4种创建方法 1、Java多线程的创建方法（4种） 1.1继承Thread

public class FirstTreading{
    public static void main(String[] args) {
        MyTread myTread = new MyTread();
        myTread.start();
    }
}
class MyTread extends Thread{
    public void run(){
        System.out.println("继承Thread类方法");
    }
}

Thread 类本质上是实现了 Runnable 接口的一个实例，代表一个线程的实例。 启动线程的唯一方法就是通过 Thread 类的 start()实例方法。 start()方法是一个 native 方法，它将启动一个新线程，后执行 run()方法。

1.2实现Runnable接口

public class SecondThreading {
    public static void main(String[] args) {
        MyTread2 myTread2 = new MyTread2();
        Thread thread = new Thread(myTread2);
        thread.start();
    }
}
class MyTread2 implements Runnable {
    @Override
    public void run() {
        System.out.println("第二种方法：实现Runnable");
    }
}

当传入一个Runnable target 参数给Thread后会调用target.run()

@Override
public void run() {
    if (target != null) {
        target.run();
    }
}

Thread的Start源码

public synchronized void start() {
    
    if (threadStatus != 0)
        throw new IllegalThreadStateException();

    
    group.add(this);

    boolean started = false;
    try {
        start0();
        started = true;
    } finally {
        try {
            if (!started) {
                group.threadStartFailed(this);
            }
        } catch (Throwable ignore) {
            
        }
    }
}

1.3实现Callable接口通过FutureTask包装的方式

public class ThirdTreading {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        // TODO Auto-generated method stub
        //创建Callable实现类的实现
        Callable