在我的程序中有一个负责定位的服务
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
//определяем переменную главного активити
MainActivity ma;
GPSTracker gps;
Teleport_user_profile_activity UP;
ReadData RD;
PostData PD;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public static String UserLoginFile;
public static String UserPassFile;
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Функция для определения местоположения
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) {
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) {
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;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
//события которые происходят если позиция поменялась
@Override
public void onLocationChanged(Location location) {
//Отправка местоположения если позиция изменилась 10_06_2013
new PostData(gps, RD, getBaseContext()).execute();
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
还有将位置数据和其他数据传输到服务器的 AsynсTask
class PostData extends AsyncTask<Void, Void, Void> {
// GPSTracker class
GPSTracker gps;
Context rdContext;
//определяем переменную главного активити
MainActivity ma;
Teleport_user_profile_activity UP;
ReadData RD;
public PostData (GPSTracker gps, ReadData RD, Context c) {
this.gps = gps;
this.RD = RD;
rdContext = c;
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
// do stuff before posting data
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
postData();
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
// do stuff after posting data
super.onPostExecute(result);
}
public void postData() {
// TODO Auto-generated method stub
// Create a new HttpClient and Post Header
//переводим значение double в стринг
double latitudep = gps.getLatitude();
double longitudep = gps.getLongitude();
double totalLatitude = latitudep;
double totalLongitude = longitudep;
String stotalLatitude = String.valueOf(totalLatitude);
String stotalLongitude = String.valueOf(totalLongitude);
// временная переменная для определения времени устройства
Time nowTime = new Time();
nowTime.setToNow();
String snowTime = String.valueOf(nowTime);
//берем информацию о юзере
RD = new ReadData(rdContext);
String UserInfo = RD.readSavedDataLogin();
String UserPass = RD.readSavedDataPass();
//посылка данных на сервер
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://myheart.pp.ua/Android_in.php");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(4);
nameValuePairs.add(new BasicNameValuePair("latitude", stotalLatitude));
nameValuePairs.add(new BasicNameValuePair("longitude", stotalLongitude));
nameValuePairs.add(new BasicNameValuePair("Android_device_time", snowTime));
nameValuePairs.add(new BasicNameValuePair("user_info", UserInfo));
nameValuePairs.add(new BasicNameValuePair("user_pass", UserPass));
nameValuePairs.add(new BasicNameValuePair("separator", "______________________________________"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
httpclient.execute(httppost);
// 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
} catch (NullPointerException e) {
e.printStackTrace();
}
在 MainActivity 上手动发送数据成功我调用 AsyncTask 如下代码
new PostData(gps, RD, getBaseContext()).execute();
但是当用户更改位置时我需要自动发送位置我认为它需要使用：
public void onLocationChanged(Location location) {
new PostData(gps, RD, getBaseContext()).execute();
}
但是当我改变位置时，我得到一个错误
06-10 14:34:57.533: E/AndroidRuntime(1544): FATAL EXCEPTION: AsyncTask #3
E/AndroidRuntime(1544): java.lang.RuntimeException: An error occured while executing doInBackground()
我不明白我做错了什么以及如何在用户更改位置时自动将数据发送到用户的位置
06-10 14:34:57.533: E/AndroidRuntime(1544): FATAL EXCEPTION: AsyncTask #3
06-10 14:34:57.533: E/AndroidRuntime(1544): java.lang.RuntimeException: An error occured while executing doInBackground()
06-10 14:34:57.533: E/AndroidRuntime(1544): at android.os.AsyncTask$3.done(AsyncTask.java:299)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-10 14:34:57.533: E/AndroidRuntime(1544): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.lang.Thread.run(Thread.java:856)
06-10 14:34:57.533: E/AndroidRuntime(1544): Caused by: java.lang.NullPointerException
06-10 14:34:57.533: E/AndroidRuntime(1544): at com.teleport.saas.PostData.postData(PostData.java:65)
06-10 14:34:57.533: E/AndroidRuntime(1544): at com.teleport.saas.PostData.doInBackground(PostData.java:50)
06-10 14:34:57.533: E/AndroidRuntime(1544): at com.teleport.saas.PostData.doInBackground(PostData.java:1)
06-10 14:34:57.533: E/AndroidRuntime(1544): at android.os.AsyncTask$2.call(AsyncTask.java:287)
06-10 14:34:57.533: E/AndroidRuntime(1544): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)