How to create a library project in Android Studio

Question

I'm new to the gradle build system and IntelliJ.

So how do I create an Android Library Project (e.g. com.myapp.lib1) and the application project (e.g. com.myapp.app) and make the build system include com.myapp.lib1 on the application project?

I went to the Project Structure -> Modules -> My App project and added a dependency to the lib project. IntelliJ now can recognize classes from the lib project when used in the app project, but when I run the app project, there are errors like:

Gradle: error: package com.myapp.lib1 does not exist

Answer 1

Had the same question and solved it the following way:

Start situation:

FrigoShare (root)
|-Modules:    frigoshare,   frigoShare-backend

Target: want to add a module named dataformats

1. Add a new module (e.g.: Java Library)

2. Make sure your settings.gradle look like this (normally automatically):

   include ':frigoshare', ':frigoShare-backend', ':dataformats'

3. Make sure (manually) that the build.gradle files of the modules that need to use your library have the following dependency:

   dependencies { ... compile project(':dataformats') }

Answer 2

For Intellij IDEA (and Android Studio) each library is a Module. Think of a Module in Android Studio as an equivalent to project in Eclipse. Project in Android Studio is a collection of modules. Modules can be runnable applications or library modules.

So, in order to add a new android library project to you need to create a module of type "Android library". Then add this library module to the dependency list of your main module (Application module).