Google Map Implementation In Android App

Introduction

Before creating a new project in Android we will see the steps to get Google Maps' API Key, which is used in the app to implement the Google Maps.

Open the URL.

And click on GET A KEY button.

A pop up will open

Click on CONTINUE and create a new project.

API Manager page will display with two options: Overview and Credentials. In credentials, enter the Android API Key name, package name and SHA-1 certificate fingerprint.

Now we will get SHA-1 certificate fingerprint because it is important. For this, first go to the Java folder of C: drive

C:\Program Files\Java\jre1.8.0_25\bin

Then run the command,

SHA-1 certificate fingerprint will be created.

Enter the SHA-1 certificate fingerprint in the "Create Android API Key" option.

And the API key will be created finally.

Created credentials will look like the following,

Now create a new project in Android Studio. Click File, New, then New Project.

Enter GoogleMapExample as the application name and create a blank activity.

Google maps need some permissions and features.

Added some tags related to user permission in the Android-Manifest.xml file.

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

ACCESS_FINE_LOCATION – It determines user’s location using GPS.
INTERNET – It checks the internet connection status of the mobile phone.
ACCESS_NETWORK_STATE – It checks network state whether data can be downloaded or not.
WRITE_EXTERNAL_STORAGE – It writes to external storage as Google maps store map data in external storage.

Add a meta-data tag just before the activity tag.

<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="@string/google_maps_key" />

Complete AndroidManifest.xml file is,

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.administrator.googlemapexample" >
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<uses-library android:name="com.google.android.maps"></uses-library>
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="@string/google_maps_key" />
<activity
android:name=".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>
</application>
</manifest>

Add google_map_key defined in above tag in strings.xml file under src, main, then res-values folder as:

<string name="google_maps_key">xxxxx-xxxxx-xxxx-xxxx-xxxxx-xxxx-xxxxx-xxx</string>

In activity_main.xml file add a fragment as:

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

In MainActivity.java file, extends FragmentActivity and implement a method called OnMapReadyCallback. The complete code of MainActivity.java file is,

package com.example.administrator.googlemapexample;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
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;
public class MainActivity extends FragmentActivity implements OnMapReadyCallback
{
private GoogleMap mMap;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/*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);
}
@Override
public void onMapReady(GoogleMap googleMap){
mMap = googleMap;
/* Show type of Google Map.*/
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
/* Show your current location.*/
mMap.setMyLocationEnabled(true);
/* Enable zooming controls.*/
mMap.getUiSettings().setZoomControlsEnabled(false);
/* Enable my location button.*/
mMap.getUiSettings().setMyLocationButtonEnabled(true);
/* Enable Compass icon.*/
mMap.getUiSettings().setCompassEnabled(true);
/* Enable Rotate gesture.*/
mMap.getUiSettings().setRotateGesturesEnabled(true);
/* Enable zooming functionality.*/
mMap.getUiSettings().setZoomGesturesEnabled(true);
/* Add a marker.*/
LatLng delhi = new LatLng(28.7373, 77.091);
mMap.addMarker(new MarkerOptions().position(delhi).title("Delhi"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(delhi));
mMap.animateCamera(CameraUpdateFactory.newLatLng(delhi));
}
}

Run the app in emulator or device:

Finally location will be displayed as per latitude and longitude defined above.