Android Studio Project Structure

Android Studio Project Structure

Hey Fellas I am right back for one more blog on Android Development for Beginners.

As I said it in the previously, in this blog we’ll see the Android Project Structure, how it is arranged and so on.

Android application development is never been easy due to its raw nature and rapid growth and changes to platform. Earlier Eclipse was the only IDE used for android development. Eclipse is developed and maintained by open source alliance. But Nowadays we have a variety of IDE’s in the market for Android Development.

By the launch of Android Studio on 15^th may 2013, Android development looks promising with the introduction of Android Studio IDE. Android Studio is an IDE based on IntelliJ IDEA that is used for android application development. This tool has more option that will enable developers to speed up application development.

Gradle Based Build System:

1.    Android Studio is an IDE based on IntelliJ IDEA that uses gradle build system. In eclipse, you can create only one build at a time. Which means, first create debug build and later you can create a release build by signing with your keystore.

2.    Android Studio projects are setup to build both a debug and a release version of the application. The debug version is signed with the developer key store key which is created automatically (Same as eclipse debug builds). The release is not signed during the build; this needs to happen after.

3.    Android Studio, make it easy to create several variants of an application, either for multi-APK distribution or for different flavours of an application. This means, you can have different builds for debug, release or may be different variant build from the same code.

4.    Eclipse ADT plugin, always generate single R.java file but, Android Studio supports multiple. The generated R.java is located in the debug folder. You can change your build variant between debug and release and accordingly it will create the R.java file in selected debug or release directory.

Android Studio Project Structure:

A project in Android Studio contains everything that defines your workspace for an app, from source code and assets, to test code and build configurations. When you start a new project, Android Studio creates the necessary structure for all your files and makes them visible in the Project window on the left side of the IDE.

By default, Android Studio displays your project files in the Android view. This view does not reflect the actual file hierarchy on disk, but is organized by modules and file types to simplify navigation between key source files of your project, hiding certain files or directories that are not commonly used. 

To see the actual file structure of the project including all files hidden from the Android view, select Project from the drop down at the top of the Project window. When you select Project view, you can see a lot more files and directories. The most important of which are the following:

1.    Main Project

This would be entire project context. Whatever you do in IntelliJ IDEA, you do that in the context of a project. A project is an organizational unit that represents a complete software solution. A project in Android Studio is like a workspace in Eclipse. In android Studio a project, can contain multiple modules. A module in Android Studio is like a project in Eclipse. In the above screenshot “HelloWorld” is the name of my project

This means that, in theory it is possible to build multiple apps with in the same project. From my personal experience, creating multiple apps with in the same project doesn’t works well. So, I recommend not to make your hands dirty trying the same thing. Instead, it is a better idea to create single app per single project.

2.    .idea

Eclipse uses project. Properties file for project specific metadata. Here in android studio, this .idea does the same thing. This means the project specific metadata is stored by Android Studio.

3.    Project Module (app)

This is the actual project folder where your application code resides. The application folder has following sub directories

a.) build: This has all the complete output of the make process i.e. classes.dex, compiled classes and resources, etc.

In the Android Studio GUI, only a few folders are shown. The important part is that your R.java is found here under build/source/r/<build variant>/<package>/R.java

b.) libs: This is a commonly seen folder in eclipse land too, which optionally can hold the libraries or .jar files.

c.) src: The src folder can have both application code and android unit test script. You will find two folders named “androidTest” and “main” correspond to src folder. The main folder contains two sub folders java and res. The java folder contains all the java codes and res contains drawables, layouts, etc.

4.    gradle:

This is where the gradle build system’s jar wrapper i.e. this jar is how AS communicates with gradle installed in Windows.

5.    External Libraries:

This is not actually a folder but a place where Referenced Libraries and information on targeted platform SDK is shown.

So in this blog we have gone through the Project Structure of Android Studio. In the next blog we will see how to install android studio.

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