Android get current GPS location

You can Find location either GPS_PROVIDER or NETWORK_PROVIDER

Overview of location services in Android , LocationManager class at the heart of location services in Android.

Here is one example which try to find location using GPS , if your GPS not available then try to use network for find location

Demo Code

Activity - AndroidGPSTrackingActivity.java

public class AndroidGPSTrackingActivity extends Activity {
  
    Button btnShowLocation;
  
    // GPSTracker class
    GPSTracker gps;
  
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
      
        btnShowLocation = (Button) findViewById(R.id.btnShowLocation);
      
        // show location button click event
        btnShowLocation.setOnClickListener(new View.OnClickListener() {
          
            @Override
            public void onClick(View arg0) {      
                // create class object
                gps = new GPSTracker(AndroidGPSTrackingActivity.this);

                // check if GPS enabled      
                if(gps.canGetLocation()){
                  
                    double latitude = gps.getLatitude();
                    double longitude = gps.getLongitude();
                  
                    // \n is for new line
                    Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();  
                }else{
                    // can't get location
                    // GPS or Network is not enabled
                    // Ask user to enable GPS/network in settings
                    gps.showSettingsAlert();
                }
              
            }
        });
    }
  
}

GPSTracke.java

public class GPSTracker extends Service implements LocationListener {

    private final Context mContext;

    // 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 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();
    }

    @Override
    public void onLocationChanged(Location location) {
    }

    @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;
    }

}

Layout - main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
   
    <Button android:id="@+id/btnShowLocation"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Location"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"/>

</RelativeLayout>

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />  
    <uses-permission android:name="android.permission.INTERNET" />

Android Interview Questions and Answer

1. Define Android?

Android is software stack for mobile devices that has middleware, operating system and specific key applications. The application must be implemented in its own process and Dalvik Virtual Machine interface. DVM device is used to effectively run several virtual machines. The byte code of java language is executed by DVM that is converted to .dex format files.

2. Define Activity?
Activity is nothing but application’s single screen that assists java code.

3. Define intent?
Intent is a class that depicts what caller has to do. Intent is send to intent resolver of Android by the caller which finds appropriate activity for intent. For example: intent is opening PDF doc and the perfect activity for intent is apps of Adobe Reader.

4. Define resource?
Resource is nothing but user defined XML, JSON or bitmap that is inserted in application build process which is later loaded from code.

5. Does Android assist profile of Bluetooth serial port?
Yes



 

6. Is it possible to start an application on powerup?
  Yes


7. Define APK format?
APK file is compacted AndroidManifest.xml file that has .apk extension. Resource files, Application code and many other files are present in this format and are compressed to single file which has .apk extension.

8. Explain translation in Android?
The data of one language can be changed to other language by Google translator by making use of XMPP for data transmission. You can type English message and choose the language that is easily understood by your country people to reach message to them.

9. On which virtual machine Android runs?
Dalvik virtual machine

10. What is the latest version in android?
Android 4.2(Jelly Bean)

12. Give the new Android platform for mobile phones?
Android 4.0 and the name given to this version is Ice-cream Sandwich. The versions that came before this are given below:
• 3. X.X Honeycomb
• 2.3. X Gingerbread
• 2.2 Froyo
• 2.0/2.1 Éclair
• 1.6 Donut
• 1.5 Cupcake

13. Give the languages that are supported by Android operating system for developing applications?
It supports all the languages that are written using java code.


14. In what ways data can be stored in Android?
• Internal storage
• Network connection
• Shared preferences
• Sqlite database
• External storage

15. What are user interface types?
• Notifications
• Views


16. Give notification types in Android?
• Dialog notification
• Status bar notification
• Tost notification

Android Google Mapview

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
 
 
  <TextView android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Waiting for location..."
    android:id="@+id/lblLocationInfo"/>
  <!-- <1> -->
 
 
  
<com.google.android.maps.MapView android:id="@+id/mapview"
   android:apiKey="0dv9akiSW0I8Vvu5Ht_ScUSAEA6tngHm7Sta1ZA"      
    android:enabled="true"
   
    android:clickable="true"
    android:focusableInTouchMode="true"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    />

   
</LinearLayout>

map.java

public class map extends MapActivity implements LocationListener { //<1>
     
      private static final String TAG = "LocationActivity";

      LocationManager locationManager; //<2>
      Geocoder geocoder; //<3>
      TextView locationText;
      MapView map; 
      MapController mapController; //<4>
     
     
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        locationText = (TextView)this.findViewById(R.id.lblLocationInfo);
        map = (MapView)this.findViewById(R.id.mapview);
        map.setBuiltInZoomControls(true);
       
        mapController = map.getController(); //<4>
        mapController.setZoom(16);
       
        locationManager = (LocationManager)this.getSystemService(LOCATION_SERVICE); //<2>
       
        geocoder = new Geocoder(this); //<3>
       
        Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); //<5>
        if (location != null) {
          Log.d(TAG, location.toString());
          this.onLocationChanged(location); //<6>
        }
      }

     
      protected void onResume() {
        super.onResume();
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 10, this); //<7>
      }

     
      protected void onPause() {
        super.onPause();
        locationManager.removeUpdates(this); //<8>
      }

     
      public void onLocationChanged(Location location) { //<9>
        Log.d(TAG, "onLocationChanged with location " + location.toString());
        String text = String.format("Lat:\t %f\nLong:\t %f\nAlt:\t %f\nBearing:\t %f", location.getLatitude(),
                      location.getLongitude(), location.getAltitude(), location.getBearing());
        this.locationText.setText(text);
       
        try {
          List<Address> addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 10); //<10>
          for (Address address : addresses) {
            this.locationText.append("\n" + address.getAddressLine(0));
          }
         
          int latitude = (int)(location.getLatitude() * 1000000);
          int longitude = (int)(location.getLongitude() * 1000000);

          GeoPoint point = new GeoPoint(latitude,longitude);
          mapController.animateTo(point); //<11>
         
        } catch (IOException e) {
          Log.e("LocateMe", "Could not get Geocoder data", e);
        }
      }

   
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

   
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub
       
    }

   
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub
       
    }

   
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
       
    }

    }

AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<uses-library android:name="com.google.android.maps" />