我现在正在做我的第一个android项目，包括在mainAcitivity调用后15分钟内将数据从手机上的传感器保存。考虑到有时手机中可能没有SD卡，我决定将文件存储在内部存储器中。
现在，我将这些问题困扰了几天：
保存数据后，我用getFilesDir()返回了目录，但是无论如何我都找不到显示的路由。
screen shot after running service
/data/user/0/com.example.liya.medicinecalendar/files/201807100711.txt
有时，根据吐司的服务开始和结束的时间并不理想。
我刚刚使用过的MainActivity.class
startService(new Intent(MainActivity.this,SaveSensorService.class));
我没有创建线程是因为我不想让屏幕活动和服务同时运行。
这是我的SaveSensorService.class
public class SaveSensorService extends Service implements SensorEventListener {
private static final String TAG = "SaveSensorService";
private Float xValue, yValue, zValue, xGyroValue, yGyroValue, zGyroValue;
SensorManager sensorManager;
private Sensor accelerometer, mGyro;
private SimpleDateFormat Date_Format,Newtime_Format;
private Calendar calendar;
private String StartTime, StopTime, CurrentTime, FileName;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d(TAG, "onStartCommand: SaveSensorService started.");
Newtime_Format = new SimpleDateFormat("HHmmss");
calendar = Calendar.getInstance();
StartTime = Newtime_Format.format(calendar.getTime());
CurrentTime = StartTime;
//calendar.add(Calendar.MINUTE, 15);//save sensor data for 15min
calendar.add(Calendar.SECOND,60);//for test
StopTime = Newtime_Format.format(calendar.getTime());
Toast.makeText(SaveSensorService.this, StartTime+" SaveSensorService is running",Toast.LENGTH_SHORT).show();
Log.d(TAG, "onCreate: Initializing Sensor Services");
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
if (accelerometer != null) {
sensorManager.registerListener(SaveSensorService.this, accelerometer, 5000000);
Log.d(TAG, "onCreate: Registered accelerometer Listener");
} else {
xValue = null;
yValue = null;
zValue = null;
;
}
mGyro = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
if (mGyro != null) {
sensorManager.registerListener(SaveSensorService.this, mGyro, 5000000);
Log.d(TAG, "onCreate: Registered Gyro Listener");
} else {
xGyroValue = null;
yGyroValue = null;
zGyroValue = null;
}
if ((accelerometer!=null || mGyro != null)&&CurrentTime.compareTo(StopTime) < 0) {
calendar = Calendar.getInstance();
CurrentTime = Newtime_Format.format(calendar.getTime());
saveSensor();
}
else {
stopSelf();
Toast.makeText(SaveSensorService.this,"Time's up or device not support."+ CurrentTime,Toast.LENGTH_SHORT).show();
}
return START_STICKY;
}
@Override
public void onDestroy() {
Log.d(TAG, "onDestroy: SaveSensorService stopped.");
Toast.makeText(SaveSensorService.this,"Sensordaten wurden gespeichert."+ CurrentTime,Toast.LENGTH_SHORT).show();
}
/*********** save the sensor data during the set time - START *******************/
public void saveSensor () {
//create a new file, named by the current time
Date_Format = new SimpleDateFormat("yyyyMMddHHmm");
FileName = Date_Format.format(calendar.getTime())+".txt";
try{
FileOutputStream fos = null;
//to prevent that the file fail to be read or created, use catch to print the error
// write in txt,
fos = openFileOutput(FileName, MODE_APPEND);
//write the first line - description
fos.write("xValue\tyValue\tzValue\txGyroValue\tyGyroValue\tzGyroValue\r\n".getBytes()); //define the first line
//append the sensor data in the file
fos.write((xValue + "\t" + yValue + "\t" + zValue + "\t" + xGyroValue + "\t" + yGyroValue + "\t" + zGyroValue + "\r\n").getBytes());
fos.flush();
fos.close();
} catch (FileNotFoundException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
Log.d(TAG, "onClick: file ist written.");
Toast.makeText(this, "Saved to " + getFilesDir() + "/" + FileName, Toast.LENGTH_SHORT).show();
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
@Override
public void onSensorChanged(SensorEvent sensorEvent) {
Sensor sensor = sensorEvent.sensor;
//get accelerometer data
if(sensor.getType()==Sensor.TYPE_ACCELEROMETER) {
Log.d(TAG, "onSensorChanged: X:" + sensorEvent.values[0] + "Y:" + sensorEvent.values[1] + "Z:" + sensorEvent.values[2]);
xValue = sensorEvent.values[0];
yValue = sensorEvent.values[1];
zValue = sensorEvent.values[2];
}
//put gyrocope data
else if(sensor.getType()==Sensor.TYPE_GYROSCOPE) {
Log.d(TAG, "onSensorChanged: XG:" + sensorEvent.values[0] + "YG:" + sensorEvent.values[1] + "ZG:" + sensorEvent.values[2]);
xGyroValue = sensorEvent.values[0];
yGyroValue = sensorEvent.values[1];
zGyroValue = sensorEvent.values[2];
}
}
/***************** save the sensor data during the set time - END *************************/
}
这是我的AndroidMainifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.liya.medicinecalendar">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/foreground"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".CalendarActivity"></activity>
<service android:name=".SaveSensorService"
android:enabled="true"/>
<receiver android:name=".AlarmReceiver"></receiver>
<service android:name=".AlarmService"
android:enabled="true"/>
</application>
</manifest>
如果有人可以在保存数据时给我一些解决该问题的建议，我将非常感激。提前非常感谢您！