Create location tracking Android App by exchanging location information over Firebase database.

This video shows the steps to setup the location listener in your App’s java code. It uses Google Maps API Key to get the maps google maps in your App. It registers the location listener using the location manager which uses the phone’s system service to get location service. This location service is responsible to get the current location of the device/ phone and display it on the edit text boxes – latitude and longitude respectively. It uses both GPS and NETWORK information to get the precise coordinates of the location.

Then it gives an Update button which is responsible to update the location information to the Firebase database. How to configure the Firebase database for your Android Application is shown in details. Though in this App it uses a button to update the database, but the database update can be automated using any desired concept by the App developer.

Finally in the map it shows/ displays the latest location updated in the database. It fetches the database” data on any change of data and extracts the required information from the datasnapshot variable. A bit of text processing id done to extract only the latest latitude and longitude updated in the database. The information of the latest latitude and longitude is used to move the camera on the map and put the marker accordingly.

We hope you like this video. For any query, suggestions or appreciations we will be glad to hear from you at: programmerworld1990@gmail.com.

Source code:

package com.example.mylocationtrackoverfbdb;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.fragment.app.FragmentActivity;

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.Arrays;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;
    private DatabaseReference databaseReference;

    private LocationListener locationListener;
    private LocationManager locationManager;
    private final long MIN_TIME = 1000;
    private final long MIN_DIST = 5;

    private EditText editTextLatitude;
    private EditText editTextLongitude;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, PackageManager.PERMISSION_GRANTED);

        editTextLatitude = findViewById(R.id.editText);
        editTextLongitude = findViewById(R.id.editText2);

        databaseReference = FirebaseDatabase.getInstance().getReference("Location");
        databaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                try {
                    String databaseLatitudeString = dataSnapshot.child("latitude").getValue().toString().substring(1, dataSnapshot.child("latitude").getValue().toString().length()-1);
                    String databaseLongitudedeString = dataSnapshot.child("longitude").getValue().toString().substring(1, dataSnapshot.child("longitude").getValue().toString().length()-1);

                    String[] stringLat = databaseLatitudeString.split(", ");
                    Arrays.sort(stringLat);
                    String latitude = stringLat[stringLat.length-1].split("=")[1];

                    String[] stringLong = databaseLongitudedeString.split(", ");
                    Arrays.sort(stringLong);
                    String longitude = stringLong[stringLong.length-1].split("=")[1];


                    LatLng latLng = new LatLng(Double.parseDouble(latitude), Double.parseDouble(longitude));

                    mMap.addMarker(new MarkerOptions().position(latLng).title(latitude + " , " + longitude));
                    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));


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


            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

//        // Add a marker in Sydney and move the camera
//        LatLng sydney = new LatLng(-34, 151);
//        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
//        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));

        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                try {
                    editTextLatitude.setText(Double.toString(location.getLatitude()));
                    editTextLongitude.setText(Double.toString(location.getLongitude()));
                } catch (Exception e) {
                    e.printStackTrace();
                }

            }

            @Override
            public void onStatusChanged(String s, int i, Bundle bundle) {

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {

            }
        };

        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

        if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    Activity#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 Activity#requestPermissions for more details.
            return;
        }

        try {
            locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DIST, locationListener);
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME, MIN_DIST, locationListener);
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }

    public void updateButtonOnclick(View view){

        databaseReference.child("latitude").push().setValue(editTextLatitude.getText().toString());
        databaseReference.child("longitude").push().setValue(editTextLongitude.getText().toString());

    }
}

<resources>
    <!--
    TODO: Before you run your application, you need a Google Maps API key.

    To get one, follow this link, follow the directions and press "Create" at the end:

    https://console.developers.google.com/flows/enableapi?apiid=maps_android_backend&keyType=CLIENT_SIDE_ANDROID&r=C3:E7:EC:00:59:FC:44:F3:06:AB:E1:EF:F8:9C:3D:8C:85:8B:53:3C%3Bcom.example.mylocationtrackoverfbdb

    You can also add your credentials to an existing key, using these values:

    Package name:
    C3:E7:EC:00:59:FC:44:F3:06:AB:E1:EF:F8:9C:3D:8C:85:8B:53:3C

    SHA-1 certificate fingerprint:
    C3:E7:EC:00:59:FC:44:F3:06:AB:E1:EF:F8:9C:3D:8C:85:8B:53:3C

    Alternatively, follow the directions here:
    https://developers.google.com/maps/documentation/android/start#get-key

    Once you have your key (it starts with "AIza"), replace the "google_maps_key"
    string in this file.
    -->
    <string name="google_maps_key" templateMergeStrategy="preserve" translatable="false">AIzaSyA9vD-5rTAXDfVCMxoGWVrfrAMd83MVkrs</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MapsActivity">


    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="550dp"
        tools:context=".MapsActivity"
        tools:layout="@android:layout/simple_spinner_dropdown_item" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="30dp"
        android:layout_marginTop="550dp"
        android:ems="10"
        android:hint="@string/latitude"
        android:inputType="textPersonName"
        android:autofillHints="" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="220dp"
        android:layout_marginTop="550dp"
        android:ems="10"
        android:hint="@string/longitude"
        android:inputType="textPersonName"
        android:autofillHints="" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="150dp"
        android:layout_marginTop="600dp"
        android:onClick="updateButtonOnclick"
        android:text="@string/update" />

</FrameLayout>

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.2'
        classpath 'com.google.gms:google-services:4.3.2'
        
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    defaultConfig {
        applicationId "com.example.mylocationtrackoverfbdb"
        minSdkVersion 28
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'com.google.android.gms:play-services-maps:17.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

    implementation 'com.google.firebase:firebase-core:17.0.0'
    implementation 'com.google.firebase:firebase-database:17.0.0'

}

apply plugin: 'com.google.gms.google-services'

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

    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality.
    -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <!--
             The API key for Google Maps-based APIs is defined as a string resource.
             (See the file "res/values/google_maps_api.xml").
             Note that the API key is linked to the encryption key used to sign the APK.
             You need a different API key for each encryption key, including the release key that is used to
             sign the APK for publishing.
             You can define the keys for the debug and release targets in src/debug/ and src/release/.
        -->
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />

        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>