how to write sensor data into file android studio

1public class Main extends Activity implements SensorEventListener {
2
3private SensorManager mSensorManager;
4private Sensor mAccelerometer;
5private FileWriter writer;
6
7/** Called when the activity is first created. */
8@Override
9public void onCreate(Bundle savedInstanceState) {
10    super.onCreate(savedInstanceState);
11    setContentView(R.layout.activiy_main);
12    mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
13    mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
14}
15
16public void onStartClick(View view) {
17    mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
18}
19
20public void onStopClick(View view) {
21    mSensorManager.unregisterListener(this);
22}
23protected void onResume() {
24    super.onResume();
25    writer = new FileWriter("myfile.txt",true);
26}
27
28protected void onPause() {
29    super.onPause();
30
31    if(writer != null) {
32       writer.close();
33    }
34}
35
36@Override
37public void onAccuracyChanged(Sensor sensor, int accuracy) {
38
39}
40
41@Override
42public void onSensorChanged(SensorEvent event) {
43
44    float x = event.values[0];
45    float y = event.values[1];
46    float z = event.values[2];
47    writer.write(x+","+y+","+z+"\n");
48
49 }
50}