Android studio

What is Android
Android is an open source and Linux-based Operating System for mobile 
devices such as smartphones and tablet computers. Android was developed by 
the Open Handset Alliance, led by Google, and other companies.
Android offers a unified approach to application development for mobile devices 
which means developers need to develop only for Android, and their applications 
should be able to run on different devices powered by Android.
The first beta version of the Android Software Development Kit (SDK) was 
released by Google in 2007, whereas the first commercial version, Android 1.0, 
was released in September 2008.
On June 27, 2012, at the Google I/O conference, Google announced the next 
Android version, 4.1 Jelly Bean. Jelly Bean is an incremental update, with the 
primary aim of improving the user interface, both in terms of functionality and 
performance.
The source code for Android is available under free and open source software 
licenses. Google publishes most of the code under the Apache License version 
2.0 and the rest, Linux kernel changes, under the GNU General Public License 
version 2.
Features
Android is a powerful operating system competing with Apple 4GS and support
great features. Few of them are listed below:
Feature Description
Beautiful UI: Android OS basic screen provides a beautiful and intuitive 
user interface.
Connectivity :GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, 
LTE, NFC and WiMAX.
Storage: SQLite, a lightweight relational database, is used for data 

storage purposes.
Media support H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, 
AAC 5.1, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, 
and BMP
Messaging SMS and MMS
Web browser Based on the open-source WebKit layout engine, coupled 
with Chrome's V8 JavaScript engine supporting HTML5 and 
CSS3.
Multi-touch Android has native support for multi-touch which was 
initially made available in handsets such as the HTC Hero.
Multi-tasking User can jump from one task to another and same time 
various application can run simultaneously.
Resizable widgets Widgets are resizable, so users can expand them to show 
more content or shrink them to save space
Multi-Language Support single direction and bi-directional text.
GCM Google Cloud Messaging (GCM) is a service that let
developers send short message data to their users on 
Android devices, without needing a proprietary sync 
solution.
Wi-Fi Direct A technology that let apps discover and pair directly, over 
a high-bandwidth peer-to-peer connection.
Android Beam A popular NFC-based technology that let users instantly 

share, just by touching two NFC-enabled phones together.
Android Applications
Android applications are usually developed in the Java language using the 
Android Software Development Kit.
Once developed, Android applications can be packaged easily and sold out either 
through a store such as Google Play or the Amazon Appstore.
Android powers hundreds of millions of mobile devices in more than 190 

countries around the world. It's the largest installed base of any mobile platform.and is growing fast. Every day more than 1 million new Android devices are 
activated worldwide.
This tutorial has been written with an aim to teach you how to develop and 
package Android application. We will start from environment setup for Android 
application programming and then drill down to look into various aspects of 
Android applications.
Setup
You will be glad to know that you can start your Android application 
development on either of the following operating systems:
 Microsoft Windows XP or later version.
 Mac OS X 10.5.8 or later version with Intel chip.
 Linux including GNU C Library 2.7 or later.
Second point is that all the required tools to develop Android applications are 
freely available and can be downloaded from the Web. Following is the list of 
software's you will need before you start your Android application programming.

• Java JDK5 or JDK6
• Android SDK
• Eclipse IDE for Java Developers (optional)
• Android Development Tools (ADT) Eclipse Plugin (optional)

Here last two components are optional and if you are working on Windows 
machine then these components make your life easy while doing Java based 
application development. So let us have a look at how to proceed to set the 
required environment.
1.Java Development kit(JDK)
You can download the latest version of Java JDK from Oracle's Java site: Java SE 
Downloads. You will find instructions for installing JDK in downloaded files, follow 
the given instructions to install and configure the setup. Finally, set PATH and 
JAVA_HOME environment variables to refer to the directory that 
contains java and javac, typically java_install_dir/bin and java_install_dir 
respectively.
If you are running Windows and have installed the JDK in C:\jdk1.6.0_15, you 
would have to put the following line in your C:\autoexec.bat file.
set PATH=C:\jdk1.6.0_15\bin;%PATH%
set JAVA_HOME=C:\jdk1.6.0_15
Alternatively, you could also right-click on My Computer, select Properties, 
then Advanced, then Environment Variables. Then, you would update the PATH 
value and press the OK button.
On Linux, if the SDK is installed in /usr/local/jdk1.6.0_15 and you use the C 

shell, you would put the following code into your .cshrc file.
setenv PATH /usr/local/jdk1.6.0_15/bin:$PATH
setenv JAVA_HOME /usr/local/jdk1.6.0_15
Alternatively, if you use an Integrated Development Environment (IDE) Eclipse, 

then it will know automatically where you have installed your Java.
2.Android SDK
You can download the latest version of Android SDK from Android’s official 
website: http://developer.android.com/sdk/index.html. If you are installing SDK 
on Windows machine, then you will find ainstaller_rXX-windows.exe, so just 
download and run this exe which will launch Android SDK Tool Setup wizard to 
guide you throughout the installation, so just follow the instructions carefully. 
Finally, you will have Android SDK Tools installed on your machine.
If you are installing SDK either on Mac OS or Linux, check the instructions 
provided along with the downloaded android-sdk_rXX-macosx.zip file for Mac OS 
and android-sdk_rXX-linux.tgz file for Linux. This tutorial will consider that you 
are going to setup your environment on Windows machine having Windows 7 
operating system.
So let's launch Android SDK Manager using the option All Programs > Android 

SDK Tools > SDK Manager
Once you launched SDK manager, it is time to install other required packages. 
By default it will list down total 7 packages to be installed, but we will suggest to 
de-select Documentation for Android SDK and Samples for SDK packages to 

reduce installation time. Next click the Install 7 Packages button.If you agree to install all the packages, select Accept All radio button and 
proceed by clicking Install button. Now let SDK manager do its work and you 
go, pick up a cup of coffee and wait until all the packages are installed. It may 
take some time depending on your internet connection. Once all the packages 
are installed, you can close SDK manager using top-right cross button.
3.Eclipse IDE
All the examples in this tutorial have been written using Eclipse IDE. So we 
would suggest you should have latest version of Eclipse installed on your 
machine.
To install Eclipse IDE, download the latest Eclipse binaries from
http://www.eclipse.org/downloads/. Once you have downloaded the installation, 
unpack the binary distribution into a convenient location. For example in 
C:\eclipse on windows, or /usr/local/eclipse on Linux and finally set PATH 
variable appropriately.
Eclipse can be started by executing the following commands on windows 
machine, or you can simply double click on eclipse.exe
%C:\eclipse\eclipse.exe
Eclipse can be started by executing the following command on Linux machine:

$/usr/local/eclipse/eclipse.
Android Development tool(ADT)plugin
This step will help you in setting Android Development Tool plugin for Eclipse. 
Let's start with launching Eclipse and then, choose Help > Software Updates 

> Install New Software. Now select all the listed plug-ins using Select All button and click Next button 
which will guide you ahead to install Android Development Tools and other 
required plugins.
5.Create Android Virtual Device
To test your Android applications you will need a virtual Android device. So 
before we start writing our code, let us create an Android virtual device. Launch 
Android AVD Manager using Eclipse menu options Window > AVD 
Manager> which will launch Android AVD Manager. Use New button to create a 
new Android Virtual Device and enter the following information, before 
clicking Create AVD button.