Android Java：停止线程而不会崩溃

Question

我创建了一个测试你的反射速度的Android应用程序。

起初应用还在 按（状态0）时，应用程序会启动一个等待几秒钟的线程，然后再显示绿屏。 显示绿色屏幕（状态1）时，您必须尽可能快地按下。 如果按绿色（状态2），则会显示反射时间

我遇到的问题当一个人太快点击时，我必须停止导致应用程序崩溃的线程（thread.stop（））。 有什么建议吗？

public class MainActivity extends Activity implements OnClickListener{
    TextView tvs,tvas;
    RelativeLayout rl;
    int state; //0=red     1=green         2=tapped-green      
    long end,start,result;
    Thread th;
    Boolean dont;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rl = (RelativeLayout) findViewById(R.id.rl);
        tvs = (TextView) findViewById(R.id.tvs);
        tvas = (TextView) findViewById(R.id.tvas);
        dont=true;

        state=0;
        Typeface myTypeface = Typeface.createFromAsset(this.getAssets(),"RobotoCondensed-Bold.ttf");
        tvs.setTypeface(myTypeface);
        tvas.setTypeface(myTypeface);
        rl.setOnClickListener(this);
        tvs.setOnClickListener(this);
        tvas.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (state) {
        case 0:
            tvs.setText("Any Min Now");
            rl.setBackgroundColor(Color.rgb(255, 68, 68));
            final Handler mHandler = new Handler();
            state=1;
            dont=true;
            th = new Thread((new Runnable() {public void run() {while (true){try {Thread.sleep(randInt());mHandler.post(new Runnable() {public void run() {
                if(dont){ //not helping
                rl.setBackgroundColor(Color.GREEN);
                start = SystemClock.uptimeMillis();
                state=2;
                }
            }});} catch (Exception e) {}}}}));
             th.start();
            break;
        case 1:
            tvs.setText("Too Soon!");
            tvas.setText("Tap AnyWhere To restart");
            dont=false;
            rl.setBackgroundColor(Color.rgb(255, 68, 68));
            state=0;
            break;
        case 2:
            end = SystemClock.uptimeMillis();
            result=end-start;
            tvs.setText("UR Reaction Time= "+result+"ms");
            tvas.setText("Tap AnyWhere To restart");
            state=0;
            dont=false;
            th.interrupt();  //giving me wrong numbers
            break;
        }

    }

    public static int randInt() {  //creates a random number
        Random rand = new Random();
        int randomNum = rand.nextInt((6000 - 2000) + 1) + 2000;
        return randomNum;
    }
}

logcat的：

03-07 22:16:05.575: I/WindowState(840): WIN DEATH: Window{45b08280 u0                                 com.afm.reflects/com.afm.reflects.MainActivity}
03-07 22:16:05.575: I/ActivityManager(840): Process com.afm.reflects (pid         32055) (adj 11) has died.
03-07 22:16:52.391: V/SmartFaceService - 3rd party pause(840): onReceive 

[android.intent.action.ACTIVITY_STATE/com.afm.reflects/create]
03-07 22:17:03.471: E/AndroidRuntime(864): Process: com.afm.reflects, PID:         864
03-07 22:17:03.471: E/AndroidRuntime(864):  at     com.afm.reflects.MainActivity.onClick(MainActivity.java:73)
03-07 22:17:03.482: W/ActivityManager(840):   Force finishing activity     com.afm.reflects/.MainActivity
03-07 22:17:03.522: V/SmartFaceService - 3rd party pause(840): onReceive 

[android.intent.action.ACTIVITY_STATE/com.afm.reflects/pause]
03-07 22:17:03.562: D/CrashAnrDetector(840): processName: com.afm.reflects
03-07 22:17:03.562: D/CrashAnrDetector(840): broadcastEvent :     com.afm.reflects data_app_crash
03-07 22:17:05.634: I/ActivityManager(840): Process com.afm.reflects (pid     864) (adj 9) has died.
03-07 22:17:05.644: I/WindowState(840): WIN DEATH: Window{45514be0 u0     com.afm.reflects/com.afm.reflects.MainActivity}
03-07 22:18:53.869: V/SmartFaceService - 3rd party pause(840): onReceive 

[android.intent.action.ACTIVITY_STATE/com.afm.reflects/create]
03-07 22:19:11.867: E/AndroidRuntime(1649): Process: com.afm.reflects, PID:     1649
03-07 22:19:11.867: E/AndroidRuntime(1649):     at     com.afm.reflects.MainActivity.onClick(MainActivity.java:73)
03-07 22:19:11.877: W/ActivityManager(840):   Force finishing activity com.afm.reflects/.MainActivity
03-07 22:19:11.917: D/CrashAnrDetector(840): processName: com.afm.reflects
03-07 22:19:11.917: V/SmartFaceService - 3rd party pause(840): onReceive 

[android.intent.action.ACTIVITY_STATE/com.afm.reflects/pause]
03-07 22:19:11.927: D/CrashAnrDetector(840): broadcastEvent : com.afm.reflects     data_app_crash