Integrate .aar file in multi-module android studio project

Question

I have a multi-module project in android studio and I want to integrate an .aar file in a module which is beeing referenced as library in the App module. The project structure is namely:

- module1
- module2
- module3
- module4
- moduleApp

The module1 is used as library reference in the module2.

build.gradle module2 :

  dependencies {
        ...
        compile project(':module1')
    }

The module2 and the other modules are referenced in th App module.

build.gradle moduleApp :

dependencies {
    ...
    compile project(':module2')
    compile project(':module3')
    compile project(':module4')
}

I need to integrate an .aar file as library in the module1, since it is required from the module1 impementation. I do the integration in the normal manner:

build.gradle module1 :

repositories {
    flatDir {
        dirs 'libs'
    }
} 

dependencies {
    compile 'package.name.of.aar:myLibrary@aar'
}

However when I run the gradle sync I receive the error:

failed to resolve package.name.of.aar:myLibrary@aar in module2
failed to resolve package.name.of.aar:myLibrary@aar in moduleApp

What should I do to let module2 and moduleApp find the .aar library? Should I include something more in their the build.gradle files?

Answer 1

Try changing

dependencies {
   compile 'package.name.of.aar:myLibrary@aar'
}

to:

dependencies {
   compile ('package.name.of.aar:myLibrary@aar'){
      transitive=true
   }
}

Alternatively, just add:

compile 'package.name.of.aar:myLibrary@aar'

to module2 and moduleApp

Answer 2

Since you are using an aar file with a flat repo , in all modules which use the module1 (in your case module2 and the app) where you need the aar file you have to add in your build.gradle the repository:

  repositories {
            flatDir {
                dirs 'libs'
            }
        }

and add the dependency:

dependencies {
   compile(name:'nameOfYourAARFileWithoutExtension', ext:'aar')
 }