android - Create single AAR file from multiple modules using Gradle -

like many others, trying generate single aar file multi-modules android project.

according this post, not supported android team because of various limitations (res & dependencies management, manifest merging, ...).

i trying come own solution fits needs. know don't have duplicated resources , external dependencies (like support libraries) provided people using lib.

my structure similar this:

/root |- lib1 |- lib2 |- lib3 

in order achieve goal, created 1 more library module, named distribute, include others modules. can share generated distribute.aar file.

/root |- lib1 |- lib2 |- lib3 |- distribute 

this build.gradle file of distribute module:

apply from: '../common.gradle' // configure properties shared accross modules apply plugin: 'com.android.library'  def allmodules = rootproject.allprojects.collect { it.name } - [rootproject.name, name] def whitelabeldependencies = [         whitelabel1: allmodules - ['lib2'],         whitelabel2: allmodules, ]  android {     def buildtypenames = buildtypes.collect { it.name }     def whitelabeltypes = productflavors.findall { 'type'.equals(it.dimension) }.collect { it.name }      whitelabeldependencies.each { whitelabel ->         def modules = whitelabel.value         def whitelabelname = whitelabel.key          whitelabeltypes.each { whitelabeltype ->             def productflavor = whitelabelname + whitelabeltype.capitalize()              buildtypenames.each { buildtype ->                 def sourceset = productflavor + buildtype.capitalize()                 def folders = ['main', whitelabelname, whitelabeltype, productflavor, whitelabelname + buildtype.capitalize(), sourceset]                  android.sourcesets.maybecreate(sourceset)                 android.sourcesets.getbyname(sourceset) {                     assets.srcdirs = getpathslist(modules, folders, 'assets')                     java.srcdirs = getpathslist(modules, folders, 'java')                     res.srcdirs = getpathslist(modules, folders, 'res')                     resources.srcdirs = getpathslist(modules, folders, 'resources')                 }             }         }     } }  afterevaluate {     whitelabeldependencies.each { whitelabel ->         def assembletask = rootproject.tasks.getbypath(":${name}:assemble${whitelabel.key.capitalize()}")         assembletask.dependson whitelabel.value.collect { ":${it}:assemble${whitelabel.key.capitalize()}" }     } }  dependencies {     whitelabeldependencies.each { whitelabel ->         whitelabel.value.each {             "${whitelabel.key}compile" project(path: ":${it}", configuration: project.whitelabelconfigurationname)         }     } }  def list<file> getpathslist(list<string> modules, list<string> folders, string sourcetype) {     return modules.collect { module ->         folders.collect { folder ->             new file("${rootproject.rootdir}/${module}/src/${folder}/${sourcetype}")         }.findall {             it.exists()         }     }.flatten() } 

this seem working, except @ runtime, application crash because can not find r class of each libx module, 1 of distribute module. there way force gradle include r class of each module.

i know file each module generated in $module/build/generated/source/r/$whitelabel/$buildtype/$package/$module/r.java, don't know how include , prevent duplicated classes (each module can depends on other one).