INTRODUCTION TO ANDROID

INTRODUCTION TO ANDROID

Android is a Linux based open source  operating System for mobile platform.It was developed by Andy Rubin in oct 2003,later on Aug 2005 google acquired Android Inc.,

1.ARCHITECTURE

Android Operating System divided into four Major category 

1.kernel (Linux)

   It provides basic system functionality like process management, memory management, device management like camera, keypad, display etc.

2.Library

  It has set of libraries including open-source Web browser engine WebKit,SQLite database, libraries to play and record audio and video, SSL libraries for Internet security etc.

 

3.Runtime

Dalvik Virtual Machine which is a kind of Java Virtual Machine for execute the android Application(App).

4.Application 

   Contacts Books, Browser, Games,Google map etc are some of the popular application used in android.

                                                 1.a.ANDROID ARCHITECTURE

2.ANDROID PLATFORM AND VERSIONS

                                     1.b.ANDROID PLATFORM AND VERSIONS 

3.ANDROID INSTALLATION

We can install android in three ways,before installing check jdk is installed,if not install jdk first.

1.Download Complete set IDE android studioq Provided by google

    download link -http://developer.android.com/sdk/installing/studio.html

2.Download Complete set IDE bundle in single link

    download link http://developer.android.com/sdk/index.html

   [ List of Tools

    Eclipse + ADT plugin

    Android SDK Tools

    Android Platform-tools

    The latest Android platform

    The latest Android system image for the emulator]

3.Download seperately all the tools to eclipse

   1.install any jdk >1.5

   2.download eclipse juno vesion for mobile platform and extract      

   3.Start Eclipse, then select Help > Install New Software.

    Click Add, in the top-right corner.

   4.In the Add Repository dialog that appears, enter "ADT  Plugin" for    the Name and the 

     following URL for the Location:

      https://dl-ssl.google.com/android/eclipse/

      Click OK.

   5.when the installation completes, restart Eclipse.

    (if you had any problem reffer this link http://developer.android.com/sdk/installing/installing-     adt.html)

 3.ANDROID PROJECT STRUCTURE

when create project in Eclipse the following folders and files are generated with corresponding android SDK library.

                                         3.ANDROID PROJECT STRUCTURE Eg. Calculator

i)SRC Folder 

It contain java class which extends Activity class,it is also called Activity.each Activity communicate with one layout,located in resource folder and it also contain general java classes.

 ii)GEN Folder

It contain two files

   a) BuildConfig.java(enable or disable   debugging)

   b)R.java(It maintain all resource ID ,resource are store in resource folder)

iii) Assets Folder

It is another area to maintain resource,but this form of resource does not have any ID in R.java.IDs are maintain  RES Folder resources only. 

iii) BIN Folder

After compile the project,android generated one apk file in this folder,this can be deployed to a android  machine that support(Minimum Version mention in Manifest file or  higher version )

iV)LIBs Folder

It contain supporting library of our project.eg:Add JSON Jar to generate JSON String 

iV)RES Folder

It contain resource in xml format ,images etc.
    a)Drawable-: maintain images eg:pp.png

    b)layout-maintain interface to communicate with activity eg: student.xml

   c)Values -: maintain String ,Color,Dimension and Styles to apply interface at runtime in    
                     activity      eg:color.xml,dim.xml,string.xml

  d)Menu -: menu to present user action
 

V) Android Manifest file 

It is  root directory contains  essential information about the application,