MobileAndroidUnderstanding Mapping Apps on the Android Platform

Understanding Mapping Apps on the Android Platform

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Introduction

Modern applications increasingly are becoming location sensitive. If you open any mobile Web site or applicable, you can invariably notice that you are asked to provide permission to allow access to your location. Many of these applications rely on mapping technologies to provide you information with this context being sensitive.

In this article, we will learn what is needed to get started building mapping mobile applications on Android platform with Google Maps.

The Basics

To develop Android applications, knowledge of building Android applications is very helpful. If you do not have Android experience but have experience in Java, it would work. If you do not have Java experience, it is recommended to get some familiarity with Java as a prerequisite.

Prerequisites

To build Android applications, you will need the latest version of Java SDK and Android Studio, a Visual Studio equivalent, to build Android applications.

You can download the latest version of Android Studio from http://developer.android.com/sdk/index.html.

When you visit that page, you should have a link to download Android Studio. Installation of Android Studio is straight forward. However, installation will not begin if you do not have JDK installed on your machine.

You can get the latest version of JDK from http://www.oracle.com/technetwork/java/javase/downloads/index.html.

At the time of writing the article, the hardware requirements for Android Studio were as follows for Windows machines.

  • Microsoft® Windows® 8/7/Vista/2003 (32- or 64-bit)
  • 2 GB RAM minimum, 4 GB RAM recommended
  • 400 MB hard disk space
  • At least 1 GB for Android SDK, emulator system images, and caches
  • 1280 x 800 minimum screen resolution
  • Java Development Kit (JDK) 7
  • Optional for accelerated emulator: Intel® processor with support for Intel® VT-x, Intel® EM64T (Intel® 64), and Execute Disable (XD) Bit functionality

Installing the Google Play Services Library

Once you have installed Android Studio, open SDK manager from Tools-> Android -> SDK manager menu open.

Map01
Figure 1: Installing the Google Play Services library

Once the SDK manager opens, select “Google Play Services,” “Google USB driver,” and click “Install xx packages.” You will need to agree to any prompts about license agreements before you can finish the installation.

Map02
Figure 2: Accepting the license agreements

Once you have done the above, the rest of the steps are conducted inside our application.

Open Android Studio and create an app (the name of my app is “com.example.vipulp.myapplication”).  Next, we will add Google Play Services as an Android Library project and reference them.

Your Android Studio after you have created the default app will look as follows:

Map03
Figure 3: The default Android Studio app

Now, double-click AndroidManifest.xml in the “Project” window under the “app” > manifests folder.

Map04
Figure 4: Selecting the AndroidManifest.xml file

We need to add a declaration within the <application> element:

<meta-data
   android_name="com.google.android.gms.version"
   android_value="@integer/google_play_services_version" />

Next, we need to get the Google Maps API key. The Maps API key is based on your application’s digital certificate, known as its SHA-1 fingerprint. To get the key for the “debug” application, we will need to use the Debug certificate in our development environment. To get the key for “release” application, make sure you use the Release certificate.

We can get the SHA-1 information for our application by executing the following command.

"C:Program FilesJavajdk1.7.0_75binkeytool.exe"
   -list -v -keystore ~/.android/debug.keystore
   -alias androiddebugkey -storepass android -keypass android

This will output your key:

Alias name: androiddebugkey
Creation date: Mar 21, 2015
Entry type: PrivateKeyEntry
Certificate chain length: 1
Certificate[1]:
Owner: CN=Android Debug, O=Android, C=US
Issuer: CN=Android Debug, O=Android, C=US
Serial number: 58c0e596
Valid from: Sat Mar 21 19:18:06 PDT 2015
   until: Mon Mar 13 19:18:06 PDT 2045
Certificate fingerprints:
   MD5:  2E:2E:44:AB:93:84:6B:E5:1F:05:5E:
         03:5E:16:52:A1
   SHA1: CA:74:BC:C7:C2:64:13:38:94:C6:81:
         AD:55:3B:D5:79:5A:3F:09:F9
   SHA256: 05:C9:5E:77:DF:BE:61:17:6D:7D:78:4C:
           9C:56:90:74:B4:DC:07:61:7E: B3:9B:BA:
           6E:FB:FB:C2:48:B4:A4:C7
   Signature algorithm name: SHA256withRSA
   Version: 3

Extensions:

#1: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier
   KeyIdentifier [
      0000: 88 58 FA B1 5E 47 EE B0
            8B FF 25 D4 D2 C0 2B 6B
            .X..^G....%...+k
      0010: 69 6B 73 B0          iks.
   ]
]

To get the Google Maps Api key, we need to register your app with Google Maps Android API 2 service. To register, you need the name of your application as well as the SHA-1 key listed above.

Go to https://console.developers.google.com and create a new project.

Map05
Figure 5: Creating a new project

Once the project is created, you will be navigated to the project dashboard. On the left bar, click “API & auth” followed by “APIs.” You will see all the APIs for that project.

Map06
Figure 6: Viewing the APIs

We now find the Google Maps Android v2 API and enable it.

Map07
Figure 7: Enabling the Google Maps Android v2 API

Click Off to “On” it. This will enable Google Maps Android API access.

Next, click “Credentials” under “APIs & Auth.”

Map08
Figure 8: Clicking “Credentials”

Click “Create new Key” under “Public API access.”

Map09
Figure 9: Creating a new key

Select Android Key.

You will be prompted to a screen that needs your SHA1 key as well as the application name in a specific format (SHA1Key;ApplicationName). Enter them and click Create.

Map10
Figure 10: Entering the application name

Your Android Maps API Key will be generated.

Map11
Figure 11: Generating your Android Maps API Key

We will now copy this APIKEY in the ApplicationManifest.xml file.

Create another node under <application> and enter your key as shown next:

<meta-data
   android_name="com.google.android.geo.API_KEY"
   android_value="API_KEY"/>

For my case, my ApplicationManifest.xml looked as under (changed highlighted):

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

   <application
      android_allowBackup="true"
      android_icon="@mipmap/ic_launcher"
      android_label="@string/app_name"
      android_theme="@style/AppTheme" >
      <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>

      <meta-data
         android:name="com.google.android.gms.version"
         android:value="@integer/google_play_services_version" />

      <meta-data
         android:name="com.google.android.geo.API_KEY"
         android:value="AIzaSyB-az_wxYh2YgmT0lsd590H8To2aO_XQ4Q"/>


   </application>

</manifest>

Next, we go to Project Settings via File -> Project Structure and add the Google Play Library Services as a reference.

Map12
Figure 12: Adding the Google Play Library Services as a reference

Click the + sign and select Library Dependency.

Map13
Figure 13: Clicking the + sign

Map14
Figure 14: Selecting Library Dependency

Click OK and you should now be able to build the project.

Next, we need to declare a few permissions.

Open ApplicationManifest.xml and provide the following permissions which are at least needed to any mapping application (you might need more).

   <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 android_name=
      "android.permission.ACCESS_COARSE_LOCATION"/>
   <uses-permission android_name=
      "android.permission.FINE_LOCATION"/>

Because Google Maps depend on OpenGL, we also need to declare that:

<uses-feature
   android_glEsVersion="0x00020000"
   android_required="true"/>

Your application manifest should look as follows:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns_android=
      "http://schemas.android.com/apk/res/android"
   package="com.example.vipulp.myapplication" >
   <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
      android:name="android.permission.ACCESS_COARSE_LOCATION"/>
   <uses-permission
      android:name="android.permission.FINE_LOCATION"/>
   <uses-feature
      android:glEsVersion="0x00020000"
      android:required="true"/>
   <application
      android_allowBackup="true"
      android_icon="@mipmap/ic_launcher"
      android_label="@string/app_name"
      android_theme="@style/AppTheme" >
      <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>

      <meta-data
         android:name="com.google.android.gms.version"
         android:value="@integer/google_play_services_version" />

      <meta-data
         android:name="com.google.android.geo.API_KEY"
         android:value="AIzaSyB-az_wxYh2YgmT0lsd590H8To2aO_XQ4Q"/>


   </application>

</manifest>

Our application is now ready to be a mapping application.

In the next article, we will learn how to add a map to an Android Application and use it.

Summary

In this article, we learned how to get started with the development tools and setup needed to build mobile Android mapping applications. I hope you have found this information useful.

About the Author

Vipul Patel is a technology geek based in Seattle. He can be reached at vipul.patel@hotmail.com. You can visit his LinkedIn profile at https://www.linkedin.com/pub/vipul-patel/6/675/508.

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