一旦線程被中斷，如何完全停止線程？

Question

在當前代碼中，我正在創建一個實現runnable的線程。 我從主啟動它，然后讓主打斷它。 但是，一旦被中斷，它將繼續運行。 我希望線程完全停止。

線程類：

public class MyThread implements Runnable {

    @Override
    public void run() {

        // string relating to the threads name
        // Note that you actually set the threads name in the main
        String threadName = Thread.currentThread().getName();


        System.out.println(threadName + " is now started...");

        System.out.println(threadName + " about to count down...");

        for (int loop = 100; loop > 1; loop--) {

            try {           
                //for 0.5 seconds
                Thread.sleep(500);      
            } catch (InterruptedException e) {
                e.printStackTrace();
                System.out.println(threadName + " was Interupted!");        
            }               

            System.out.println(loop);
        }           

    }

}

主要：

public class Runner {

    public static void main(String[] args) {

        //Create thread from class
        MyThread myt= new MyThread();

        //Passing in the thread from class and also naming it
        Thread t= new Thread(myt, "My Thread");

        //Actually starts the thread
        t.start();

        //Main thread has a sleep for 5 seconds then interrupts t
        try {
            Thread.sleep(5000);
            t.interrupt();
            System.out.println("Interupting...");
        } catch (InterruptedException e) {
            e.printStackTrace();                
        }       

    }

}

輸出（注意線程如何不停止）：

My Thread is now started...
My Thread about to count down...
100
99
98
97
96
95
94
93
92
Interupting...
java.lang.InterruptedException: sleep interrupted
My Thread was Interupted!
91
    at java.lang.Thread.sleep(Native Method)
    at threads.MyThread.run(MyThread.java:22)
    at java.lang.Thread.run(Unknown Source)
90
89
88
87
86
85

Answer 1

只是break循環：

catch (InterruptedException e) {
    e.printStackTrace();
    System.out.println(threadName + " was Interupted!");
    Thread.currrentThread().interrupt();
    break;
}

Answer 2

只需使用一個boolean標志，該標志將在run()方法中執行任何操作之前檢查，並根據其狀態執行所需的任何操作。 確保它應該是volatile 。

只需調用myt.setRunning(false)而不是t.interrupt()

示例CDE：

class MyThread implements Runnable {

    private volatile boolean isRunning=true;

    @Override
    public void run() {             

        for (int loop = 100; loop > 1; loop--) {                 

            if(!isRunning){
               // break or do whatever is needed here
            }             
        }    
    }               

}

Answer 3

只要正確地編寫run（）方法，即可使其在中斷時脫離循環，而不僅僅是繼續。

線程確實具有stop（）方法，但出於某種原因不建議使用； 它將使事物處於不一致甚至潛在的不穩定狀態。 不要使用它！

Answer 4

對於這樣的重復任務，您還可以使用TimerTask ：

請注意，此代碼不會從零停止。

public class CountdownTask extends TimerTask {

    private int from;

    public CountdownTask(int from) {
        this.from = from;
    }

    @Override
    public void run() {
        System.out.println(from--);
    }
}

private void example() throws InterruptedException {
    Timer timer = new Timer("Countdown");
    timer.schedule(new CountdownTask(100), 0, 500);
    Thread.sleep(2000); //do something
    timer.cancel(); //stop task
}