java - 如何在不使用 stop 方法的情况下停止线程？

Question

在下面的Java程序中，我在HashMap中存储3个线程，我创建了Th类的3个对象，它们是从Thread类扩展的(我已经尝试通过实现Runnable但它也不起作用!)，我想通过分配空值在3秒后停止t2我无法停止它，我不想使用stop()方法，因为它已被弃用，它仅在我使用start方法启动线程时才有效，而如果我启动它则不起作用使用ExecutorService的execute方法的线程

public class TestingThreads {

    static HashMap<String, Thread> trds = new HashMap<>();

    static Th t1 = new Th("Th1");
    static Th t2 = new Th("Th2");
    static Th t3 = new Th("Th3");

    public TestingThreads() {

    }

    public static void main(String[] args) {
        long ct = System.currentTimeMillis();

        ExecutorService executor = Executors.newCachedThreadPool();

        trds.put("t1", t1);
        trds.put("t2", t2);
        trds.put("t3", t3);
        executor.execute(t1);
        executor.execute(t2);
        executor.execute(t3);
        executor.shutdown();
        new Thread() {

            @Override
            public void run() {
                while (true) {
                    if (ct + 3000 < System.currentTimeMillis()) {
                        trds.put("t2", null);
                        trds.remove("t2");
                        System.out.println("Size = " + trds.size());
  //I dont wanna use the stop() method as is it deprecated and it only works when I use start method to run the Thread while it is not working with execute() method of class ExecutorService 
                        // t2.stop();
                        t2 = null;
                        break;
                    }
                }
            }

        }.start();
    }
}

class Th extends Thread {

    String name;
    Random rm = new Random();

    public Th(String name) {
        this.name = name;
    }

    @Override
    public void run() {
        while (!this.isInterrupted()) {
            int i = rm.nextInt(500);
            try {
                Thread.sleep(i);
            } catch (InterruptedException ex) {
            }
            System.out.println(name + " " + i);
        }
    }
}

Answer 1

这只是一个线程的示例..创建一个静态 volatile boolean 标志。

static volatile boolean RUN_THREAD_FLAG= true;
Thread yourThread= new Thread(){
    @Override
    public void run() {
        try{
            // you can add your other conditions inside while condition
            // and AND it with the FLAG
            //while(RUN_THREAD_FLAG && yourCondition)
            while(RUN_THREAD_FLAG){ 
                sleep(SLEEP_TIME); //OR your task
            }
        } catch(Exception e){
                e.printStackTrace();
            }
    }
};
yourThread.start();

当你想停止线程时，只需设置RUN_THREAD_FLAG= false

PS:您应该始终使用某些 FLAG 或其他方法尽可能长时间地正确结束线程。尽可能不要使用任何中断方法。