USB connection creates another activity

Question

I have such a complicated problem to solve alone.

I have a sample program that just tells me that the name of the device that connect to the USB port on the tablet, the device I use is the card reader.

Every time I turn the player on or off, my activity is finished and then restarts, I wonder if this is possible avoid restarting the activity.

In other words, my activity is finished and soon one is to open another.

I used android: launchMode = "SingleInstance" but not resolved

The Android version is 2.3.4.

My code:

public class MainActivity extends Activity {

    @SuppressLint("NewApi")
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView txtView = (TextView)findViewById(R.id.textView1);

        int[] input = InputDevice.getDeviceIds();

        if(input.length == 5) {
            InputDevice A = InputDevice.getDevice(input[4]);
            txtView.setText(A.getName());
        }
        else {
            txtView.setText("Not Device");
        }
    }