Reputation: 153
I am very new to Android Studio and Java.
I am in the process of developing an app. This app will basically follow a layered architecture, with different layers, for instance, the UI, Data Access Layer, Service layer etc.
I am not clear on the differences between packages and modules.
My question is, where would one put all these different layers, in modules, or packages?
Pointing to @Angel reponse to this question, the only difference between the two is \, modules define a more strict rule by who can access them, by having to import the namespaces for the modules.
Upvotes: 15
Views: 11956
Reputation: 15155
A module is the container for the source code within a project. A single project can have multiple modules, but each module is a separate set of code and resources.
For instance, when you create a new project with the default settings, Android Studio generates a module called app
. This module holds all of the source code, resource files and app-level settings for your application.
But, if you create a new project with a Phone/Tablet application as well as an Android Wear application, you will see two modules; mobile
and wear
. Each of these modules contain the source code, resource files and app-level settings for their respective application.
You can also create another module to be shared between multiple modules; this module would be considered a library module.
A package is essentially the directory (folder) to which source code belongs. Normally, this is a directory structure that uniquely identifies your application; such as com.example.app
. Then you can create packages within your application package that separates your code; such as com.example.app.ui
or com.example.app.data
.
Therefore, to answer your question, the package for each application resides within the src/main/java
directory of the application module. You could place a separate package within the application pacakge to separate each "layer" of your application architechture.
Just for a visual example, this is the basic structure for one of my projects:
project
|-- build.gradle
|-- settings.gradle
~
|-- common // a common library module for both mobile and wear
| |-- build.gradle
| |-- proguard-rules.pro
| +-- src
| +-- main
| |-- AndroidManifest.xml
| |-- assets
| |-- java
| | +-- com
| | +-- example
| | +-- library // common module library package
| | |-- data
| | +-- util
| +-- res
|
|-- mobile // mobile application module
| |-- build.gradle
| |-- proguard-rules.pro
| +-- src
| +-- main
| |-- AndroidManifest.xml
| |-- assets
| |-- java
| | +-- com
| | +-- example
| | +-- app // mobile module application package
| | |-- data
| | |-- ui
| | +-- util
| +-- res
|
+-- wear // wear application module
|-- build.gradle
|-- proguard-rules.pro
+-- src
+-- main
|-- AndroidManifest.xml
|-- assets
|-- java
| +-- com
| +-- example
| +-- app // wear module application package
| |-- data
| |-- ui
| +-- util
+-- res
Upvotes: 34