想要在设备离线时将数据存储在本地数据库中，并在在线时从数据库中获取并发送到服务器

Question

1. 我每 15 分钟启动一次警报服务，每 15 分钟向服务器发送一次数据。但是当 wifi 不可用时，我无法将数据发送到服务器。我想在 15 分钟后将数据存储在本地数据库中，并在设备在线时发送到服务器。

2. 我的应用在 gps 被禁用时停止工作，我想要在 gps 被禁用时发出警报。

这里是服务代码

public class LocationService extends Service implements LocationListener {

public static String LOG = "Log";
JSONParser jsonParser = new JSONParser();
private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 0 meters
private static final long MIN_TIME_BW_UPDATES = 1000; // 1 second
protected LocationManager locationManager;
private SQLiteHandler db;

public LocationService(Context context) {
    this.mContext = context;
}

public LocationService() {
    super();
    mContext = LocationService.this;
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    db = new SQLiteHandler(getApplicationContext());
    HashMap<String, String> user = db.getUserDetails();
    String uid = user.get("uid");
    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
    String IMEINo =sharedPreferences.getString("IMEI NO",null);

    SimpleDateFormat simpleDateFormat =
            new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ");
    Calendar calendar = Calendar.getInstance();
    Date now = calendar.getTime();
    String deviceTimeStamp = simpleDateFormat.format(now);
    Toast.makeText(this,( "latitude" + latitude +"longitude" + longitude +uid), Toast.LENGTH_LONG).show();
    Log.i(LOG, "Service started");
    Log.i("asd", "This is sparta");
    new MyAsyncTask().execute((Double.toString(Double.parseDouble(uid))),
            (Double.toString(getLocation().getLongitude())),
            (Double.toString(getLocation().getLatitude())),
            (Double.toString(Double.parseDouble(IMEINo))),
            (deviceTimeStamp));

    return START_STICKY;
}
@Override
public void onCreate() {
    super.onCreate();
    Log.i(LOG, "Service created");
}

@Override
public void onDestroy() {
    super.onDestroy();
    Log.i(LOG, "Service destroyed");
}

private class MyAsyncTask extends AsyncTask<String, String, String>{

    @Override
    protected String doInBackground(String... params) {
        // TODO Auto-generated method stub
        postData(params[0],params[1],params[2],params[3],params[4]);

        return "call";
    }

    protected void onPostExecute(String result){

        Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
    }
    public void postData(String uid, String longitude, String latitude, String IMEI, String deviceTimeStamp) {
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://enftracker.com/app_script/connect1.php");

        try {
            // Add your data
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
            nameValuePairs.add(new BasicNameValuePair("uid", uid));
            nameValuePairs.add(new BasicNameValuePair("longitude", longitude));
            nameValuePairs.add(new BasicNameValuePair("latitude", latitude));
            nameValuePairs.add(new BasicNameValuePair("IMEI", IMEI));
            nameValuePairs.add(new BasicNameValuePair("deviceTimeStamp", deviceTimeStamp));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));


            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);

        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
    }

}
public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            if (isNetworkEnabled) {
                //updates will be send according to these arguments
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                        // TODO: Consider calling
                        //    ActivityCompat#requestPermissions
                        // here to request the missing permissions, and then overriding
                        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                        //                                          int[] grantResults)
                        // to handle the case where the user grants the permission. See the documentation
                        // for ActivityCompat#requestPermissions for more details.
                        return null;
                    }
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();

                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
    return location;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}

Answer 1

你可以利用这个方法

@Override
public void onProviderEnabled(String provider) {
    if (provider.equals(LocationManager.GPS_PROVIDER) {
        boolean isEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

    }
}