Wie kann ich kontinuierliche Standortaktualisierungen in Android erhalten, wie in Google Maps?

Ich baue eine Android-App, mit der Freunde nachverfolgen können. Während mein Freund die App aktiviert hat und seine GPS- und Mobilfunkdaten aktiviert hat, muss ich ihn auf meinem Gerät verfolgen. Das ist das Konzept. 

Ich habe die LocationListener-Klasse implementiert. Jetzt kann ich den zuletzt aktualisierten Standort entweder von Gps oder Network abrufen. Ich werde jedoch nicht aktualisiert, wenn ich nicht Google Maps starte und zu meiner Anwendung zurückkehre. Nach dem Googeln erfuhr ich, dass der Standortcache nur von GMaps aktualisiert wird.!

1. Gibt es eine alternative Möglichkeit, den Standort kontinuierlich zu aktualisieren?
2. Was ist, wenn ich die Position nach dem gesperrten Gerät ohne Verwendung von Wakelock fortsetzen muss?

Dies ist meine Standortlistener-Klasse:

package com.amazinginside;

/** AMAZING LOCATION SUPPORT CLASS, Devoloped By SANGEETH NANDAKUMAR */

import Android.app.AlertDialog;
import Android.app.Service;
import Android.content.Context;
import Android.content.DialogInterface;
import Android.content.Intent;
import Android.location.Location;
import Android.location.LocationListener;
import Android.location.LocationManager;
import Android.os.Bundle;
import Android.os.IBinder;
import Android.provider.Settings;

public class AmazingLocation extends Service implements LocationListener
{
    private final Context mContext;
    boolean isGPSEnabled = false;
    boolean isNetworkEnabled = false;
    boolean canGetLocation = false;

    Location location;
    double latitude=0.0;
    double longitude=0.0;

    //MINIMUM DISTANCE FOR UPDATE (meters)
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 0 Meters

    //MINIMUM TIME BETWEEN UPDATES
    private static final long MIN_TIME_BW_UPDATES = 1000 * 0; // 0 Seconds

    //LOCATION MANAGER
    protected LocationManager locationManager;

    //CONSTRUCTOR
    public AmazingLocation(Context context)
    {
        this.mContext = context;
        getLocation();
    }

    //LOCATION PROVISION
    public Location getLocation()
    {
        try
        {
            //GET LOCATION MANAGER
            locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
            //CHECK GPS STATE
            isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
            //CHECK NETWORK STATE
            isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled)
            {
                //NO LOCATION PROVIDERS
            }
            else
            {
                this.canGetLocation = true;

                /** GET LOCATION FROM NETWORK */
                //FIRST GET LOCATION FROM NETWORK
                if (isNetworkEnabled)
                {
                    //REQUEST LOCATION
                    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    if (locationManager != null)
                    {
                        //START WITH LAST KNOWN LOCATION
                        location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                        //EXTRACT LOCATION
                        if (location != null)
                        {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }

                /** GET LOCATION FROM GPS SENSOR */
                //THEN GET LOCATION FROM GPS
                if (isGPSEnabled)
                {
                    if (location == null)
                    {
                        //REQUEST GPS LOCATION
                        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                        if (locationManager != null)
                        {
                            //EXTRACT LAST KNOWN LOCATION
                            location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            //RETURN LOCATION
                            if (location != null)
                            {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                            }
                        }
                    }
                }
            }

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return location;
    }

    //STOP GPS SENSOR
    public void stopUsingGPS()
    {
        if(locationManager != null)
        {
            locationManager.removeUpdates(AmazingLocation.this);
        }
    }

    //EXTRACT LATTITUDE
    public double getLatitude()
    {
        if(location != null)
        {
            latitude = location.getLatitude();
        }

        // return latitude
        return latitude;
    }

    //EXTACT LONGITUDE
    public double getLongitude()
    {
        if(location != null)
        {
            longitude = location.getLongitude();
        }

        // return longitude
        return longitude;
    }

    //CAN I GET THE LOCATION.?
    public AmazingStatus canGetLocation()
    {
        AmazingStatus status=new AmazingStatus();
        if(this.canGetLocation)
        {
            status.setStatus(true);
            status.setErrorcode(0);
            status.setErrormsg("Task completed");
        }
        else
        {
            status.setStatus(false);
            status.setErrorcode(145);
            status.setErrormsg("Please turn on GPS access manually");
        }
        return status;
    }

    //SHOW LOCATION SETTINGS
    public AmazingStatus showSettingsAlert()
    {
        final AmazingStatus status=new AmazingStatus();
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
        alertDialog.setTitle("REQUIRES LOCATION ACCESS");
        alertDialog.setMessage("Please allow GPS access to this app");

        //POSSITIVE REPLY
        alertDialog.setPositiveButton("Allow", new DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog,int which)
            {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
                status.setStatus(true);
                status.setErrorcode(0);
                status.setErrormsg("Task completed");
            }
        });

        //NEGATIVE REPLY
        alertDialog.setNegativeButton("Deny", new DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int which)
            {
                status.setStatus(false);
                status.setErrorcode(408);
                status.setErrormsg("User denied permission");
                dialog.cancel();
            }
        });

        // Showing Alert Message
        alertDialog.show();
        return status;
    }

    //UNUSED OVERRIDE METHORDS...
    @Override
    public void onLocationChanged(Location location)
    {
        getLocation();
    }

    @Override
    public void onProviderDisabled(String provider)
    {
    }

    @Override
    public void onProviderEnabled(String provider)
    {
        getLocation();
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras)
    {
        getLocation();
    }

    @Override
    public IBinder onBind(Intent arg0)
    {
        return null;
    }

}

Diese meine onCreate() Methode:

@Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //CREATE A BUTTON HANDLER
    Button start_btn=(Button)findViewById(R.id.start_location_streaming);
    //ON BUTTON CLICK EVENT
    start_btn.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            //REPEAT A METHORD AT SPECIFIC INTERVALS
            Timer myTimer = new Timer();
            myTimer.schedule(new TimerTask()
            {
                @Override
                public void run()
                {
                    TimerMethod();
                }

            }, 0, 8000);
        }
    });  }

Dies sind andere Methoden:

private void TimerMethod()
{
    //START METHORD
    this.runOnUiThread(Timer_Tick);
}

//LOCATION REPORTING METHORD
private Runnable Timer_Tick = new Runnable()
{
    public void run()
    {
        Toast.makeText(MainActivity.this, "Current latitude : "+Double.toString(getLocation().latitude), Toast.LENGTH_SHORT).show();
        Toast.makeText(MainActivity.this, "Current longitude : "+Double.toString(getLocation().longitude), Toast.LENGTH_SHORT).show();
    }
};

private LatLng getLocation()
{
    //CREATE A LOCATION CLASS INSTANCE
    AmazingLocation gps = new AmazingLocation(this);
    //RETRIVE LOCATION
    double latitude = gps.getLatitude();
    double longitude = gps.getLongitude();
    //RETURN LOCATION
    LatLng loc=new LatLng(latitude,longitude);
    return loc;
}  

Das Problem ist nun, dass der Toast nur den zuvor bekannten Ort anzeigt und nicht aktualisiert wird, es sei denn, ich habe Google Maps geöffnet und zurückgegeben. 

Jede Hilfe wird für mich großartig sein.