How to allow an inner class to send messages?

Question

I want to make an application able to locate a phone by sending an sms to him , the application is installed on the phone that needs to be locate , I helped myself with tutorials and I got 2 java files : GPSTracker.java and MainActivity.java and there is an inner class named Main inside the class the MainActivity , the class Main got an "extends Broadcast Receiver" and MainActivity got an "extends Activity" , the class needs "BroadcastReceiver" to know when there are receiving messages , but finally when I launch the app it don't work (maybe because it's an inner class) and even after I added thoses lines in the manifest : But here are my 2 java files and my manifest :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.guillaume.essai3">
android:versionCode="1"
android:versionName="1.0" >

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.example.guillaume.essai3.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <receiver android:name="com.example.guillaume.essai3.MainActivity$Main">
        <intent-filter>
            <action android:name="android.provider.Telephony.SMS_RECEIVED"/>
        </intent-filter>
    </receiver>

</application>
<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="17" />

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

<uses-permission android:name="android.permission.SEND_SMS"></uses-permission>
    <uses-permission android:name="android.permission.WRITE_SMS"></uses-permission>
    <uses-permission android:name="android.permission.READ_SMS"></uses-permission>

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





</manifest>

MainActivty.java :

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.location.LocationListener;
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;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;
import android.telephony.SmsManager;
import java.lang.String;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.IntentSender;
public class MainActivity extends Activity {

    public class Main extends BroadcastReceiver  {

        GPSTracker gps = new GPSTracker(MainActivity.this);
        final SmsManager sms = SmsManager.getDefault();

        public void onReceive(Context context, Intent intent) {

            double latitude, longitude;
            final Bundle bundle = intent.getExtras();

            try {

                if (bundle != null) {

                    final Object[] pdusObj = (Object[]) bundle.get("pdus");

                    for (int i = 0; i < pdusObj.length; i++) {

                        SmsMessage currentMessage = SmsMessage.createFromPdu((byte[]) pdusObj[i]);
                        String phoneNumber = currentMessage.getDisplayOriginatingAddress();

                        String senderNum = phoneNumber;
                        String message = currentMessage.getDisplayMessageBody();

                        Log.i("SmsReceiver", "senderNum: " + senderNum + "; message: " + message);
                        latitude = gps.getLatitude();
                        longitude = gps.getLongitude();

                        int duration = Toast.LENGTH_LONG;
                        Toast toast = Toast.makeText(context, "senderNum: " + senderNum + ", message: " + message, duration);
                        toast.show();
                        if (message.contains("12345")) {
                            sms.sendTextMessage("0634****", null, "hello https://www.google.com/maps/preview/@" + latitude + "," + longitude + ",22z", null, null);
                        }
                    } // end for loop
                } // bundle is null

            } catch (Exception e) {
                Log.e("SmsReceiver", "Exception smsReceiver" + e);
            }

        }
    }
}

GPSTracker.java :

        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;
        import android.util.Log;

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;
                // First get location from Network Provider
                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;
    }
}

So do you have any idea why the sms is not sent with the latitude and longitude ? Thank you very much in advance :)

Answer 1

You cannot have a BroadcastReceiver defined as a non-static inner class.

A non-static inner class contains a reference to its outer class. This means that in order to create a new instance of the inner class, you need to have an instance of the outer class.

When Android tries to start your BroadcastReceiver, it tries to create a new instance of the inner class. This fails, because Android does not have an instance of the outer class to use in the creation.

Solution: Move all your inner classes to full-fledged classes (in their own source files).