如何退出线程

public class ThreadTest extends Thread {

    private volatile boolean exit = false;

    @Override
    public void run() {

        while (!exit) {
            try {
                System.out.println("######");
                Thread.sleep(10000);  //休眠中了,shutdown（），会结束线程
                System.out.println("^^^^^^^^^"); //正在执行这行代码时，shutdown（），exit被修改为true了，退出循环了，线程结束
            } catch (InterruptedException e) {
                exit = true;
                e.printStackTrace();
                break;
            }
        }
    }

    
    public void shutdown() {
        exit = true;
        this.interrupt();
    }
    
    
    public static void main(String[] args) throws InterruptedException {
        ThreadTest thread = new ThreadTest();
        thread.start();
        Thread.sleep(3000);
        thread.shutdown();
    }
}