Background service for sensor in android

Question

I have implemented a code that opens an app when we shake our device. As far as i kept all my code into the MainActivity and without any background service, it all went well. But its not working when i tried to add a background service as i want it keep working without going into an app every time. So can anybody suggest me where am i doing wrong.Thanks!

BackgroundService.java

public class BackgroundService extends Service implements SensorEventListener {

    public BackgroundService() {
    }
    private SensorManager mSensorManager;
    private Sensor mSensor;
    private long lastUpdate = 0;
    private float last_x, last_y, last_z;
    private static final int SHAKE_THRESHOLD = 600;


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

        // Get sensor manager on starting the service.
        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

        // Registering...
        mSensorManager.registerListener(this, mSensor, SensorManager.SENSOR_DELAY_NORMAL);

        // Get default sensor type
        mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        // Get sensor manager on starting the service.
        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

        // Registering...
        mSensorManager.registerListener(this, mSensor, SensorManager.SENSOR_DELAY_NORMAL);

        // Get default sensor type
        mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

        return START_STICKY;

    }

    @Override
    public IBinder onBind(Intent intent) {
        throw new UnsupportedOperationException("Not Yet Implemented");
    }

    @Override
    public void onSensorChanged(SensorEvent sensorEvent) {

        mSensorManager.registerListener(this, mSensor, SensorManager.SENSOR_DELAY_NORMAL);

        Sensor mySensor = sensorEvent.sensor;

        mSensorManager.registerListener(this, mySensor, SensorManager.SENSOR_DELAY_NORMAL);

        if (mySensor.getType() == Sensor.TYPE_ACCELEROMETER) {

            float[] values = sensorEvent.values;
            float x = values[0];
            float y = values[1];
            float z = values[2];

            long curTime = System.currentTimeMillis();
            if ((curTime - lastUpdate) > 100) {
                long diffTime = (curTime - lastUpdate);
                lastUpdate = curTime;
                float speed
                        = Math.abs(x + y + z - last_x - last_y - last_z) / diffTime * 10000;
                if (speed > SHAKE_THRESHOLD) {
                    openWhatsApp();
                }
                last_x = x;
                last_y = y;
                last_z = z;
            }
            // Stop the sensor and service
               mSensorManager.unregisterListener(this);
               stopSelf();
        }
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int i) {
    }


    public void openWhatsApp() {
        Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.whatsapp");
        if (launchIntent != null) {
            startService(launchIntent);
        }
    }

}

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        Intent i = new Intent(MainActivity.this, BackgroundService.class);
        startService(i);
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="joshipinak.com.shakeshooksaken">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

        </activity>
        <service android:name=".BackgroundService" />
    </application>

</manifest>

Welcome to Stackoverflow. Is this really a [minimal](http://stackoverflow.com/help/mcve) example? — loki, Jan 21 '17 at 11:17

score 5 · Accepted Answer · edited Dec 11 '20 at 15:43

In GitHub Android Examples there is a complete app. It uses the command pattern like your code for checking the sensor values and AlarmManager.

In this question on SO is an example using the SensorEventListener interface.

The Android developer site says to use IntentService on this page. You can also read what is the difference between Service and IntentService in this question on SO.

These links may also help you:

Background service for sensor in android

1 Answers1