Tutorial #101: Getting started with Flurry Analytics in Android

Hello everyone!

Now-a-days, developers keep track of user activity and generate useful statistics about an application. Hence, analytics plays an important role in mobile applications. There are plenty of analytics solutions that exists in the market today. For example, ACRA is a library enabling Android Application to automatically post their crash reports to a GoogleDoc form. It is targetted to Android application developers to help them get data from their applications when they crash or behave erroneously.

Through this post, we will learn how to integrate the get started with the Flurry Analytics SDK in Android. The Flurry Analytics SDK provides you with the tools and resources you need to gain a deep level of understanding about your user’s behavior in your apps. Set up advanced analysis of complex events, with metrics, segments and funnels to better track your user’s habits and performance.

Pre-requisites: Eclipse IDE, Android SDK, Flurry Developer Account

Step 1: Sign up for Flurry developer account

First, you need to create a developer account by signing up over here. Once the account is created, download the required SDK. Now, login into your account and create a new application that will display all the analytical information.

Step 2: Create Android application project

Launch Eclipse IDE and a create a new Android application project called AndroidFlurryAnalyticsDemo with package name com.app.flurry.android. Copy the FlurryAnalytics.jar file inside the libs folder of your Android project.

Step 3: Initialize Flurry and simulate a crash

Create a new class called FlurryApplication that extends the Application class in Android. This class will initialize Flurry on application launch.

FlurryApplication.java

package com.app.flurry.application;

import android.app.Application;
import com.app.flurry.utils.AppConstants;
import com.flurry.android.FlurryAgent;

public class FlurryApplication extends Application {
	@Override
	public void onCreate() {
	super.onCreate();

        //set log enabled
        FlurryAgent.setLogEnabled(true);

        //set log events
        FlurryAgent.setLogEvents(true);
        
        // initialize Flurry
        FlurryAgent.init(this, AppConstants.FLURRY_API_KEY);
    }
}

Next, let us simulate a crash event in our Activity class as follows!

MainActivity.java

package com.app.flurry.main;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import com.app.flurry.android.R;
import com.app.flurry.utils.AppConstants;
import com.flurry.android.FlurryAgent;

public class MainActivity extends Activity {

	private Button m_objBtnPrint;
	private String m_strName = null;

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

		m_objBtnPrint = (Button)findViewById(R.id.btnPrint);
		m_objBtnPrint.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				FlurryAgent.onEvent("click button");	
				simulateCrashEvent();
			}
		});
	}

	public void simulateCrashEvent(){
		try{
			m_strName.concat("This will result in null pointer exception");
		}catch(Exception ex){
			ex.printStackTrace();
			FlurryAgent.onError("error", "Error occurred on click of button", ex); 		
		}
		FlurryAgent.logEvent("print button clicked");	
	}

	@Override
	protected void onStart(){
		super.onStart();
		FlurryAgent.onStartSession(this, AppConstants.FLURRY_API_KEY);
	}

	@Override
	protected void onStop(){
		super.onStop();		
		FlurryAgent.onEndSession(this);
	}
}

activity_main.xml

<RelativeLayout 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="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/txt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <Button
        android:id="@+id/btnPrint"
        android:layout_below="@+id/txt1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/print" />

</RelativeLayout>

AndroidManifest.xml

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

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="19" />

    <!-- required permission -->
    <uses-permission android:name="android.permission.INTERNET" />
    <!-- optional permission - highly recommended -->
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <!-- optional permission -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:name="com.app.flurry.application.FlurryApplication"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name="com.app.flurry.main.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" />
    </application>

</manifest>

Save all changes and run the application on an Android device. If no errors occur, then you should see the following output from the dashboard page of the Flurry application.

crashes_page

events_page

users_page

Source code for this tutorial can be found over here

Reference: Flurry SDK Developer’s page

Tutorial #100: The Switch from KitKat to Lollipop!

Hey everyone!

The new Android version release has brought few changes in the way developers used certain widgets to create layouts. For instance, starting from Lollipop, Android introduces a new Toolbar widget. As mentioned by Chris Banes in this post, the Toolbar widget is a generalization of the Action Bar pattern that gives developers much more control and flexibility. Similarly, Android has made a “switch” in the way the current Switch widget is implemented.

As mentioned on the developer’s page, a Switch is a two-state toggle switch widget that can select between two options. The user may drag the “thumb” back and forth to choose the selected option, or simply tap to toggle as if it were a checkbox. Through this tutorial, we will learn how to implement the Switch widget in Android.

Pre-requisites: Eclipse IDE, Android SDK

Step 1: Create a new Activity class called TestSwitchActivity in any of your existing Android projects and write the following code,

TestSwitchActivity.java

import android.app.Activity;
import android.os.Bundle;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.Switch;
import android.widget.TextView;

public class TestSwitchActivity extends Activity {

	private TextView m_tvSwitchStatus;
	private Switch m_objSwitch;

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

		m_tvSwitchStatus = (TextView) findViewById(R.id.switchStatus);
		m_objSwitch = (Switch) findViewById(R.id.sampleSwitch);

		//set the switch to ON 
		m_objSwitch.setChecked(true);
		//attach a listener to check for changes in state
		m_objSwitch.setOnCheckedChangeListener(new OnCheckedChangeListener() {

			@Override
			public void onCheckedChanged(CompoundButton buttonView,
					boolean isChecked) {

				if(isChecked){
					m_tvSwitchStatus.setText("Switch is currently ON");
				}else{
					m_tvSwitchStatus.setText("Switch is currently OFF");
				}

			}
		});

		if(m_objSwitch.isChecked()){
			m_tvSwitchStatus.setText("Switch is currently ON");
		}
		else {
			m_tvSwitchStatus.setText("Switch is currently OFF");
		}
	}
}

Step 2: Create Switch widget

In previous versions of Android, we would implement a Switch widget in our layout as follows,

activity_switch.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:padding="5dp">

    <Switch
        android:id="@+id/sampleSwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp"
        android:text="@string/action" />

    <TextView
        android:id="@+id/switchStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/sampleSwitch"
        android:layout_marginTop="22dp"
        android:text="@string/status"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

According to recent changes, the Switch widget can now be implemented using SwitchCompat. The difference is that it does not make any attempt to use the platform provided widget on those devices which it is available normally.

activity_switch.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp" >

    <android.support.v7.widget.SwitchCompat
        android:id="@+id/sampleSwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp"
        android:text="@string/action"
        android:thumb="@drawable/thumb_pressed"
        android:track="@drawable/bg"/>

    <TextView
        android:id="@+id/switchStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/sampleSwitch"
        android:layout_marginTop="22dp"
        android:text="@string/status"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

In this case, our Activity file would be as follows,

TestSwitchActivity.java

package com.app.lollipop.test;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.SwitchCompat;
import android.util.Log;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.TextView;

public class TestSwitchActivity extends Activity {

	private TextView m_tvSwitchStatus;
	private SwitchCompat m_objSwitch;

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

		try {

			m_tvSwitchStatus = (TextView) findViewById(R.id.switchStatus);
			m_objSwitch = (SwitchCompat)findViewById(R.id.sampleSwitch);
			m_objSwitch.setThumbResource(R.drawable.apptheme_switch_thumb_holo_light);
			m_objSwitch.setTrackResource(R.drawable.apptheme_switch_track_holo_light);
			m_objSwitch.setTextOn("ON");
			m_objSwitch.setTextOff("OFF");
			
			//set the switch to ON 
			m_objSwitch.setChecked(true);
			//attach a listener to check for changes in state
			m_objSwitch.setOnCheckedChangeListener(new OnCheckedChangeListener() {

				@Override
				public void onCheckedChanged(CompoundButton buttonView,
						boolean isChecked) {

					if(isChecked){
						m_tvSwitchStatus.setText("Switch is currently ON");
					}else{
						m_tvSwitchStatus.setText("Switch is currently OFF");
					}

				}
			});

			if(m_objSwitch.isChecked()){
				m_tvSwitchStatus.setText("Switch is currently ON");
			}
			else {
				m_tvSwitchStatus.setText("Switch is currently OFF");
			}
		}catch(Exception e){
			e.printStackTrace();
			Log.i("App", "Error occurred due to" +e.getMessage());
		}
	}
}

Finally, save all changes and run the Android application project on an emulator or a real device. If no errors occur then you should see the following output!

Android Switch on Pre Lollipop versions

Android Switch on Pre Lollipop versions

Android Switch on Lollipop

Android Switch on Lollipop

From here on, we will learn more about the recent changes in Android 5.0. We will also try to implement the same in the upcoming tutorials.

Reference: Android Switch

Tutorial #99: Send e-mail using JavaMail in JSP

Hi everyone!

JavaMail is a well known Java API used to send and receive email via SMTP, POP3 and IMAP. It mainly provides a platform-independent and protocol-independent framework to build mail and messaging applications. In addition, the JavaMail API package is also included in the Java EE platform.

JavaMail facilitates the sending of an e-mail via Gmail SMTP server, using both TLS and SSL connection. Through this tutorial, we will learn how to send an e-mail using JavaMail in a sample JSP page.

Pre-requisites: Eclipse IDE for Java EE developers, Apache Tomcat 7

Step 1: Create new Dynamic web project

Launch Eclipse IDE and create a new Dynamic web project called SendEmailUsingJSP with target runtime as Apache Tomcat 7.

Step 2: Add external jar files

In order to implement the sending of an e-mail, developers need to download and use the latest version of the JavaMail API in their web projects. For this tutorial, I will be using the mail-1.4.7.jar version of the JavaMail API. Make sure you add the .jar file in the WEB-INF/lib folder of your web project.

Step 3: Create JSP page

Create a new index.jsp page inside the WebContent folder of your web project and write the following code.

index.jsp

<%@ pageimport="javax.servlet.http.*,javax.servlet.*" %>
<%@ page import="javax.mail.internet.*,javax.activation.*"%>
<%@ page import="java.io.*,java.util.*,javax.mail.*"%>
<%

    //username for abc@gmail.com will be "abc"
	String username = "sender_username";
	String password = "sender_password";
	String result = null;

	try {
		
        Properties props = System.getProperties();
		props.setProperty("mail.transport.protocol", "smtp");
		props.setProperty("mail.host", "smtp.gmail.com");
		props.put("mail.smtp.auth", "true");
		props.put("mail.smtp.port", "465");
		props.put("mail.debug", "true");
		props.put("mail.smtp.socketFactory.port", "465");
		props.put("mail.smtp.socketFactory.class",
				"javax.net.ssl.SSLSocketFactory");
		props.put("mail.smtp.socketFactory.fallback", "false");

		Session emailSession = Session.getInstance(props,
				new javax.mail.Authenticator() {
					protected PasswordAuthentication getPasswordAuthentication() {
					return new PasswordAuthentication("sender_username","sender_password");
				}
		});

		emailSession.setDebug(true);
		Message message = new MimeMessage(emailSession);
		message.setFrom(new InternetAddress(
				"sender_username@gmail.com"));
		message.setRecipients(Message.RecipientType.TO,
				InternetAddress.parse("xyz@hotmail.com"));
		message.setSubject("Test mail from Java");
		message.setText("Hello. this is a test");

		Transport transport = emailSession.getTransport("smtps");
		transport.connect("smtp.gmail.com", username, password);
		transport.sendMessage(message, message.getAllRecipients());

		result = "Successfully sent email";

	   } catch (MessagingException e) {
		result = "Unable to send email";
	}
%>
<html>
<head>
<title>Send Email using JSP</title>
</head>
<body>
	<center>
		<h1>Send Email using JSP</h1>
	</center>
	<p align="center">
		<%
			out.println("Result: " + result + "\n");
		%>
	</p>
</body>
</html>

Finally, save all changes and run the application on the Tomcat server. If no errors occur then you should see the following output!

output

Reference: JavaMail API

Tutorial #98: Calling web services using PL/SQL in Oracle

Web services are widely used to as a means of communication between two multiple devices. Oracle also allows developers to consume web services using certain built-in packages. Moreover, one can extend a relational database’s storage, indexing, and searching capabilities to include web services. Through this tutorial, we will learn how to call a simple web service using PL/SQL in Oracle. We would using a public testing platform for services utilizing JavaScript Object Notation (JSON).

Pre-requisites: Oracle 11gR2 database with *SQLPlus, Windows 7 (64 bit)

Step 1: Writing the PL/SQL query

Open the SQL Plus command prompt and login using your database credentials. Once logged in successfully execute the following command in order to enable DBMS_OUTPUT statements.

set serveroutput on

In order to call web services, Oracle provides the UTL_HTTP package. It helps make hyper-text transfer protocol (HTTP) callouts from PL/SQL and SQL. One can use it to access data on the Internet or to call Oracle Web Server cartridges. We would be creating a stored procedure to use the same. Our PL/SQL procedure would be as follows,

create or replace procedure call_webservice as
  t_http_req  utl_http.req;
  t_http_resp  utl_http.resp; 
  t_response_text VARCHAR2 (2000);

begin
 
  t_http_req:= utl_http.begin_request('http://date.jsontest.com/','GET','HTTP/1.1');
  t_http_resp:= utl_http.get_response(t_http_req);
  UTL_HTTP.read_text(t_http_resp, t_response_text);
  DBMS_OUTPUT.put_line('Response> status_code: "' || t_http_resp.status_code || '"');
  DBMS_OUTPUT.put_line('Response> reason_phrase: "' ||t_http_resp.reason_phrase || '"');    
  DBMS_OUTPUT.put_line('Response> data:' ||t_response_text); 
  utl_http.end_response(t_http_resp);
 
end;

create_procedure

Step 2: Executing the PL/SQL query

Now, execute the above PL/SQL procedure using the below command,

exec call_webservice

Once the procedure has executed successfully you will see the following output,

execute_procedure

Reference: UTL_HTTP in Oracle

Tutorial #97: Generate multi-language PDF using iText in Java

Hi everyone,

iText is a PDF software that can be used to create PDF documents dynamically using Java, .NET, Android etc. Based on the comments I received of late, iText can be used to generate multi-language PDF documents for Java, web and other applications.

iTextG is a special version of iText built for Android and Google App Engine.

Differences between the iText core library and the Android/GAE port are as follows,

1. iTextG uses SpongyCastle instead of Bouncy Castle. Make sure to download and include the right jars namely scprov-jdk15on and scpkix-jdk15on.

2. References to any of the classes not on the Google App Engine whitelist have been removed.

Through this tutorial, we will learn how to generate a multi-language PDF using the iText library in Java.

Pre-requisites: Eclipse IDE, Windows 7 (64 bit), iText software ( itext-2.1.7.jar)

Launch Eclipse IDE and create a new Java console application project called JavaPDFGeneration with package name com.app.generate. Create a new Java class called GeneratePDF and add the following code!

GeneratePDF.java

package com.app.pdfgenerate;

import java.io.FileOutputStream;
import com.lowagie.text.Chunk;
import com.lowagie.text.Document;
import com.lowagie.text.Font;
import com.lowagie.text.FontFactory;
import com.lowagie.text.HeaderFooter;
import com.lowagie.text.Paragraph;
import com.lowagie.text.Phrase;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.PdfPCell;
import com.lowagie.text.pdf.PdfPTable;
import com.lowagie.text.pdf.PdfWriter;

public class GeneratePDF {
	
    public static void main(String arg[]) throws Exception {
              
       try {
                       
            Document document = new Document();
			String encoding = "Identity-H";
			Font fontNormal = FontFactory.getFont(("F:/programs/pdf/fonts/Roboto-Black.ttf"), encoding,BaseFont.EMBEDDED, 8, Font.NORMAL);
			PdfWriter.getInstance(document, new FileOutputStream("F:/programs/pdf/test.pdf"));
			HeaderFooter header = new HeaderFooter(new Paragraph("Header", fontNormal), false);
			HeaderFooter footer = new HeaderFooter(new Paragraph("footer", fontNormal), false);
			document.setHeader(header);
			document.setFooter(footer);
			document.open();

			Chunk chunkEnglish = new Chunk("Hello World " + "\n", fontNormal);
			Chunk chunkBrazil = new Chunk("Olá Mundo " + "\n", fontNormal);

			PdfPTable table = new PdfPTable(2);
			table.addCell("Locale");
			table.addCell("Translated Text");

			PdfPCell cellEnglish = new PdfPCell(new Phrase(chunkEnglish));
			table.addCell(new PdfPCell(new Phrase(new Chunk("English",fontNormal))));
			table.addCell(cellEnglish);

			PdfPCell cellBrazil = new PdfPCell(new Phrase(chunkBrazil));
			table.addCell(new PdfPCell(new Phrase(new Chunk("Brazil",fontNormal))));
			table.addCell(cellBrazil);

			document.add(table);
			document.close();

			System.out.println("PDF generation complete....");
	
		  } catch (Exception e) {
			System.out.println("Error occurred while generating PDF" + e.getMessage());
			e.printStackTrace();
	      }
   }
}

Save all changes and run the application. If no errors occur then you should see the PDF file (test.pdf) created in the specified output directory.

output

Reference: iText library

Tutorial #96: Implement multi-language support in Android

Hey friends!

Today, Android has become one of the dominant mobile operating systems in the world. Android applications are now used by people living across the globe. It is important for developers to build applications that can support multiple languages. In order to reach maximum users, an application should handle text, audio files, numbers, currency, and graphics in ways appropriate to the locales where it will be used.

By default Android considers English as the primary language and loads the string resources from res/values/strings.xml file. In order to add support for another language, one needs to create a values folder by appending an hyphen and the ISO language code. For example if you want to add support for French, you should create a values folder named values-fr and keep a strings.xml file in it with all the strings translated into French language.

As mentioned on the developer’s page, it’s always a good practice to extract UI strings from your application code and keep them in an external file. Through this tutorial, we will learn how to implement multi-language support in Android.

Pre-requisites: Eclipse IDE, Android SDK

Step 1: Create Android project

Launch Eclipse IDE and create a new Android application project called AndroidMultiLanguageSupportDemo. Let’s keep the package name as com.app.multilanguage. Choose the target SDK as Android 4.4 (API level 19)

Step 2: Add multi-language support

As mentioned earlier, we need to create multiple values folder for the appropriate language depending on the language code as follows!

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello_world">Hello world!</string>
</resources>

res/values-fr/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <string name="hello_world">bonjour le monde!</string>
</resources>

MainActivity.java

package com.app.multilanguage;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

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

res/layout/activity_main.xml

<RelativeLayout 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="${relativePackage}.${activityClass}">

    <TextView
        android:id="@+id/txtView"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24sp"
        android:textColor="#FE2E2E"
        android:text="@string/hello_world" />

</RelativeLayout>

Finally, save all changes. Make sure no errors are present. Run the application on an Android device and you should see the following output for the respective languages.

English

English

Japanese

Japanese

Hindi

Hindi

French

French

That’s it for this tutorial. Hope it helps! 🙂

Reference: Supporting different languages

Tutorial #95: Resolving the Dalvik compiler limitation on 65K methods

Hello everyone!

In previous versions of the Android operating system, as applications grew in size one would encounter build errors that would indicate that the application has reached a limit of the Android application build architecture. The error would be as follows,

Conversion to Dalvik format failed:
Unable to execute dex: method ID not in [0, 0xffff]: 65536

If you observe the error closely, it specifies the number 65536. As mentioned on the developer’s page, this number is significant as it represents the total number of references that can be invoked by the code within a single Dalvik Executable (dex) bytecode file.

Developers hence need to resolve this error by adding multidex support to their application. From Android 5.0 (Lollipop) onwards, Android uses a runtime called ART which natively supports loading multiple dex files from application APK files. However, through this tutorial, we will learn one of the ways to resolve the Dalvik compiler limitation in previous (older) versions of Android.

Pre-requisites: Android Studio (version 1.0.0-rc4), Gradle plugin (version 2.2.1), latest Android SDK (with build tools installed for version 21)

Step 1: Configure application to add multidex support

Launch the Android Studio IDE and open any of your existing Android projects that contain more than 65K methods due to external libraries (.jar) files. Open the build.gradle file of your project and add the following lines of code,

apply plugin: 'com.android.application'
....
....

    compileSdkVersion 21
    buildToolsVersion '21.1.1'

    defaultConfig {
        applicationId "com.app.multidex"
        minSdkVersion 19
        targetSdkVersion 20
        versionCode 1
        versionName "1.0"

        // Enabling multidex support.
        multiDexEnabled true
    }
    buildTypes {
        release {
            runProguard true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile 'com.android.support:multidex:1.0.0'
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile files('libs/my_large_file1.jar')
    compile files('libs/my_large_file2.jar')
}

As seen above, it is important to specify the multiDexEnabled setting in the defaultConfig, buildType, or productFlavor sections of your Gradle build file. In addition, one needs to add the multidex support library as a dependency in the dependencies section.

Step 2: Edit AndroidManifest.xml file

In the manifest file one needs to add the MultiDexApplication class from the multidex support library to the application element as follows,

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.app.multidex">
    <application
        ...
        android:name="android.support.multidex.MultiDexApplication">
        ...
    </application>
</manifest>

Finally, save all changes. Make sure no errors are present. Once the project has compiled successfully the Android build tools construct a primary dex (classes.dex) and supporting (classes2.dex, classes3.dex) as needed.

multidex_support_android

Alternatively, one can also use an opensource GitHub project that when downloaded provides a custom_rules.xml build script that can be easily integrated in any Android application.

Reference: Building apps with over 65K methods

Tutorial #94: Using Retrofit for Android

Hello friends!

In one of my previous tutorials, I had talked about using the Volley networking library in Android. However, Volley is less documented and is totally focused on handling individual, small HTTP requests.

Retrofit on the other hand makes it incredibly easy to download JSON or XML data from a web API and parse it into a Plain Old Java Object (POJO). It’s released by Square and offers very easy to use REST API’s. Through this tutorial, we will learn how to use Retrofit for Android.

Pre-requisites: Eclipse IDE, Android SDK

Step 1: Create Android project

Create a new Android application project called AndroidRetrofitExample with package name com.app.retrofit. Choose the target SDK as Android 4.4 (API level 19)

Step 2: Create REST service interface

Create a new interface called GithubApiService that will help fetch the list of contributors for a particular repository as follows,

GithubApiService.java

package com.app.retrofit;

import java.util.List;
import retrofit.http.GET;
import retrofit.http.Path;

public interface GithubApiService {
	@GET("/repos/{owner}/{repo}/contributors")
	List<Contributor> contributors(
			@Path("owner") String owner,
			@Path("repo") String repo
	);
}

Step 3: Create Activity class

Now, let’s implement our MainActivity class. We will create an AsyncTask in order to call the public Github API service.

MainActivity.java

package com.app.retrofit;

import java.util.List;
import retrofit.RestAdapter;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends Activity {

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

	private class GetUserInfo extends AsyncTask<String, Void, String>{

		@Override
		protected String doInBackground(String... params) {
			// TODO Auto-generated method stub	
			try{ 
				RestAdapter restAdapter = new RestAdapter.Builder()
				.setEndpoint("https://api.github.com") 
				.build();

				GithubApiService github = restAdapter.create(GithubApiService.class);
				List<Contributor> contributors = github.contributors("pscholl", "glass_snippets");

				for (Contributor contributor : contributors) {
					Log.i("App", contributor.login + " - " + contributor.contributions);
				}

			}catch(Exception e){
				e.printStackTrace();
				return "failure";
			}	
           return "success";
	    }
      }
}

The RestAdapter is the class through which your API interfaces are turned into callable objects. By default, Retrofit will give you sane defaults for your platform but it allows for customization.

Contributor.java

package com.app.retrofit;

//POJO class
public class Contributor {
	
	// GitHub username
	public String login; 
	// Commit count
	public int contributions;
	
	public String getLogin() {
		return login;
	}
	public void setLogin(String login) {
		this.login = login;
	}
	public int getContributions() {
		return contributions;
	}
	public void setContributions(int contributions) {
		this.contributions = contributions;
	} 
}

Note: Make sure you have added the android.permission.INTERNET feature in the AndroidManifest.xml file. One also needs to add the following .jar files in the libs folder of the Android project.

  • retrofit-1.4.1.jar
  • okhttp-1.3.0-jar-with-dependencies.jar
  • gson-2.2.4.jar

Finally, save all changes. Make no errors are present. Run the application on an Android device and you should the following output in the Logcat window!

output

That’s it for this tutorial. Stay tuned for more! 🙂

Reference: Retrofit for Android

Tutorial #93: Implement CardView in Android

Hello everyone!

Prior to Android 5.0 Lollipop, developers would use open source libraries in order to implement a Card based view in Android. However, the latest release of Android now provides a CardView widget to show information inside cards that have a consistent look across the platform. In general, CardView widgets can have shadows and rounded corners.

As mentioned on the developer’s page, in order to create a card with a shadow, one can use the card_view:cardElevation attribute. CardView uses real elevation and dynamic shadows on Android 5.0 (API level 21) and above and falls back to a programmatic shadow implementation on earlier versions. Through this tutorial, we will learn how to implement a CardView in Android.

Pre-requisites: Eclipse IDE, Android SDK 5.0

Step 1: Create Android project

Launch the Eclipse IDE and create a new Android application project called AndroidLollipopNewExamples with package name com.app.lollipop.test. Let the target SDK be Android 5.0 (API level 21)

Step 2: Create Card layout

Now, let’s create our card layout using XML. Create a new XML file called activity_cardview and add the following code!

activity_cardview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:gravity="center_horizontal"
    android:layout_height="match_parent">

    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_marginTop="20dp"
        android:layout_width="200dp"
        android:layout_height="100dp"
        card_view:cardCornerRadius="8dp"
        card_view:cardBackgroundColor="#C92A2A">

        <TextView
            android:id="@+id/info_text_header"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="@string/sample_text_header" />

        <ImageView
            android:id="@+id/info_image"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:contentDescription="@string/sample_text_image"
            android:layout_gravity="center"
            android:layout_marginTop="2dp"
            android:src="@drawable/ic_launcher" />

        <TextView
            android:id="@+id/info_text_footer"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:paddingTop="80dp"
            android:text="@string/sample_text_footer" />
    </android.support.v7.widget.CardView>

</LinearLayout>

To set the corner radius in your layouts, use the card_view:cardCornerRadius attribute. To set the corner radius in your Java code, use the CardView.setRadius method. Finally, in order to set the background color of a card, use the card_view:cardBackgroundColor attribute.

strings.xml

<resources>
    <string name="app_name">AndroidLollipopNewExamples</string>
    <string name="sample_text_header">Sample card header</string>
    <string name="sample_text_footer">Sample card footer</string>
    <string name="sample_text_image">Sample image</string>
</resources>

Step 3: Create Activity class

Our Activity class called TestCardActivity would be as follows,

TestCardActivity.java

package com.app.lollipop.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;

public class TestCardActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_cardview);
	}	
}

No changes are to be made to the AndroidManifest.xml file. Run the application on an emulator and you should see the following output!

output

Reference: Creating Cards in Android

Tutorial #92: Live Streaming using Vitamio in Android

Hello friends!

Live video streaming is one of the most challenging functionalities to incorporate in an Android application. RTMP (Real Time Messaging Protocol) was developed by Adobe for Flash Player to transmit real-time media (audio, video) between a server and flash player. However, Android does not support RTMP out of the box. Hence, developers need to use third party libraries in order to stream a RTMP video.

Vitamio is an open multimedia framework or library for Android and iOS, with full and real hardware accelerated decoder and renderer. It supports streaming network protocols such as RTSP, RTMP, HLS and can play 720p/1080p HD mp4, mkv, m4v, mov, flv, avi, rmvb and many other video formats in Android and iOS. Through this tutorial, we will learn how to implement live streaming using Vitamio in Android.

Pre-requisites: Eclipse IDE, Android SDK

Step 1: Create Android project

Launch Eclipse IDE and create a new Android application project called AndroidVitamioDemo with package name com.app.vitamio.stream. Choose the target SDK as Android 4.4

Step 2: Add reference to Vitamio bundle (library)

Before creating the streaming Activity class, one needs to download the Vitamio Bundle and add the same as a reference to the above Android project. The Vitamio library will provide the required classes to setup, initialize and play the live stream.

Step 3: Create Activity class

Create a new Activity class called LiveStreamingActivity in order to implement the streaming process. Developers can also add an EditText to obtain the path or URL of the media file. For this tutorial, I have directly provided the URL to the media file.

LiveStreamingActivity.java

package com.app.vitamio.stream;

import io.vov.vitamio.LibsChecker;
import io.vov.vitamio.MediaPlayer;
import io.vov.vitamio.widget.MediaController;
import io.vov.vitamio.widget.VideoView;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Toast;

public class LiveStreamingActivity extends Activity {

	private String pathToFileOrUrl= "rtmp://204.107.26.252:8086/live/796.high.stream";
	private VideoView mVideoView;
	
	@Override
	public void onCreate(Bundle icicle) {
		super.onCreate(icicle);
		
		if (!LibsChecker.checkVitamioLibs(this))
			return;
		
		setContentView(R.layout.activity_video_stream);
		mVideoView = (VideoView) findViewById(R.id.surface_view);

		if (pathToFileOrUrl == "") {
			Toast.makeText(this, "Please set the video path for your media file", Toast.LENGTH_LONG).show();
			return;
		} else {

			/*
			 * Alternatively,for streaming media you can use
			 * mVideoView.setVideoURI(Uri.parse(URLstring));
			 */
			mVideoView.setVideoPath(pathToFileOrUrl);
			mVideoView.setMediaController(new MediaController(this));
			mVideoView.requestFocus();

			mVideoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
				@Override
				public void onPrepared(MediaPlayer mediaPlayer) {
					// optional need Vitamio 4.0
					mediaPlayer.setPlaybackSpeed(1.0f);
				}
			});
		}

	}
	
	public void startPlay(View view) {
		if (!TextUtils.isEmpty(pathToFileOrUrl)) {
			mVideoView.setVideoPath(pathToFileOrUrl);
		}
	}

	public void openVideo(View View) {
		mVideoView.setVideoPath(pathToFileOrUrl);
	}

}

activity_video_stream.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal">

        <Button
            android:id="@+id/start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="startPlay"
            android:text="@string/play_video"/>
    </LinearLayout>

    <io.vov.vitamio.widget.VideoView
        android:id="@+id/surface_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:onClick="openVideo"
        android:text="@string/open_video"/>

</LinearLayout>

Step 4: Add permissions to Manifest file!

One needs to update the AndroidManifest.xml file in order to include the required permissions.

AndroidManifest.xml

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />
 
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name">
        <activity
            android:name=".LiveStreamingActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
       
        <activity
            android:name="io.vov.vitamio.activity.InitActivity"
            android:configChanges="orientation|screenSize|smallestScreenSize|keyboard|keyboardHidden|navigation"
            android:launchMode="singleTop"
            android:theme="@android:style/Theme.NoTitleBar"
            android:windowSoftInputMode="stateAlwaysHidden" />
        
    </application>

</manifest>

Save all changes. Make sure no errors are present. Run the application on an Android device and you should see the following output!

output_1

output_2

That’s it for this tutorial. Stay tuned for more! 🙂

Reference: Vitamio Bundle