android - 为什么线程不停止？

Question

我的服务生成一个新线程，并根据 typically recommended java 停止它中断()的方法。当我停止服务时，我停止了 onDestroy() 中的线程。服务停止，到达中断代码。但是，线程很快就会从 Runnable 的开头重新启动。

public class DoScan extends Service {
    public volatile Thread runner;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        startThread();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "DoScan.onDestroy");
        stopThread();
    }


    public synchronized void startThread(){
        if(runner == null){
            android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "DoScan.startthread");     
            runner = new Thread(new ScanningThread());
            runner.start();
        }
    }
    /* use a handler in a loop cycling through most of oncreate.
     * the scanningthread does the work, then notifies the svc's uithread
     */

    public synchronized void stopThread(){
        if(runner != null){
            android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "DoScan.stopthread");
            Thread moribund = runner;
            runner = null;
            moribund.interrupt();
            android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "interrupted?" + moribund.isInterrupted());
        }
    }
        }

Answer 1

我认为最安全的方法是设置一个标志，以便线程在其主循环中检查它。

class ScanningThread extends Thread {
    // Must be volatile:
    private volatile boolean stop = false;

    public void run() {
        while (!stop) {
            System.out.println("alive");
        }
        if (stop)
            System.out.println("Detected stop");
    }

    public synchronized void requestStop() {
        stop = true;
    }
}

public synchronized void startThread(){
    if(runner == null){
        android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "DoScan.startthread");         
        runner = new ScanningThread();
        runner.start();
    }
}

public synchronized void stopThread(){
    if(runner != null){
        android.util.Log.v("@@@@@@@@@@@@@@@@@@@@", "DoScan.stopthread");
        runner.requestStop();
        runner = null;
    }
}