Thread.currentThread()和this的区别

1. Thread.currentThread()可以获取当前线程的引用，一般都是在没有线程对象又需要获得线程信息时通过Thread.currentThread()获取当前代码段所在线程的引用。

2. 如果调用isInterrupted返回true,this就是当前线程对象，此时Thread.currentThread()与this表示同一对象。否则，就必须使用Thread.currentThread()获取当前线程。

3.调用Thread.currentThread()方法的时候多半是不知道调用的是哪一个线程的。

public class MyThread extends Thread {

    public MyThread(){

        System.out.println("------" + "构造函数开始" + "------");
        Thread testThread = Thread.currentThread();
        System.out.println("Thread.currentThread().getName() = " + testThread.getName());
        System.out.println("Thread.currentThread().isAlive() = " + testThread.isAlive());
        System.out.println("this.getName() = " + this.getName());
        System.out.println("this.isAlive() = " + this.isAlive());
        System.out.println("Thread.currentThread() == this : " + (testThread == this));
        System.out.println("------" + "构造函数结束" + "------");

    }

    @Override
    public void run(){

        Thread testThread = Thread.currentThread();
        System.out.println("------" + "run()开始" + "------");
        System.out.println("Thread.currentThread().getName() = " + testThread.getName());
        System.out.println("Thread.currentThread().isAlive() = " + testThread.isAlive());
        System.out.println("this.getName() = " + this.getName());
        System.out.println("this.isAlive() = " + this.isAlive());
        System.out.println("Thread.currentThread() == this : " + (testThread == this));
        System.out.println("------" + "run()结束" + "------");

    }

    public static void main(String[] args) throws InterruptedException {
        MyThread myThread = new MyThread();
        myThread.setName("A");
        myThread.start();
    }
}
------构造函数开始------
Thread.currentThread().getName() = main
Thread.currentThread().isAlive() = true
this.getName() = Thread-0
this.isAlive() = false
Thread.currentThread() == this : false
------构造函数结束------
------run()开始------
Thread.currentThread().getName() = A
Thread.currentThread().isAlive() = true
this.getName() = A
this.isAlive() = true
Thread.currentThread() == this : true
------run()结束------

查看Thread的源码可以发现

    public Thread() {
        init(null, null, "Thread-" + nextThreadNum(), 0);
    }

1. 不指定Thread名字时,Thread会自动给name赋值，此时this指向的MyThread子线程，但子线程还没有启动所以

所以：在构造函数中this.getName() = Thread-0

2. 然后myThread子线程启动

------run()开始------
Thread.currentThread().getName() = A
Thread.currentThread().isAlive() = true
this.getName() = A
this.isAlive() = true
Thread.currentThread() == this : true
------run()结束------

程序若执行main方法

执行结果，此时的this和Thread.currentThread()指向不是同一个线程实例。
也就是说，this指向的还是new MyThread()创建的那个线程实例，而不是new Thread(thread)创建的那个实例即thread。

https://blog.csdn.net/smartboy_01/article/details/89356010