Develop Reference

How to declare the dependencies of a library project when those dependencies should be fulfilled by the consuming application?

I'm developing an android library that depends on some third party aars and jars.
Currently, these dependencies are declared in the library module's gradle buildscript like so:
repositories {
flatDir{
dirs 'libs', 'android-libs'
}
}
dependencies{
compile(name: 'threetenabp-1.0.5', ext: 'aar')
compile fileTree(include: ['*.jar'], dir: 'libs')
}
However, this results in the dependencies' classes being built into the aar, potentially causing conflicts when the library is used in an application.
How can I reference these dependencies from my library without actually packaging them into the library?
I have tried changing the declarations from "compile" to "provided" and then compiling the files into the application, but when I do this my library fails to build.

After some reading at https://docs.gradle.org/current/userguide/dependency_management.html#sec:how_to_declare_your_dependencies I eventually figured out that using compile fileTree will package the dependencies into the output library. To avoid this, declare each dependency individually, using the following syntax:
dependencies {
compile: name: 'filename-without-extension'
}
And the dependencies will no longer be packaged into the output.
The project making use of the output aar will still need to include the flat-dir repository that holds the jar files, like so:
repositories {
flatDir{
dirs 'libs'
}
}

Gradle doesn't find acra

I have an Android project in which I have been using ACRA 4.6.0 with a static jar file, all working fine. I have tried to change this to use the latest ACRA by the maven dependency in build.gradle:
dependencies {
compile fileTree(dir: 'libs', include: '*.jar')
testCompile 'junit:junit:4.12'
compile 'ch.acra:acra:4.8.5'
compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:design:23.4.0'
}
in my build.gradle. However this causes the build to fail with errors like:
CJApp.java:13: error: cannot find symbol
import org.acra.ACRAConfiguration;
^
symbol: class ACRAConfiguration
location: package org.acra
So far as I can tell gradle is not downloading anything for acra. I have tried adding mavenCentral() to the repositories list with no effect.
What else do I need to do, and is there any way of determining just what gradle has downloaded?

Are you sure that the class org.acra.ACRAConfiguration is included in the new version: acra:4.8.5 which you're suddenly linking to? If not, this is a simple matter of incompatibility. In that case, it should be resolved if you step the version back to 4.6.0.
Have you checked that the build downloads the file from Maven Central? This should be clearly visible when giving gradle the -i flag - it will print every URL as it downloads them.

ACRAConfiguration has moved to org.acra.config. Just adjust your import.

Android Studio - MavenCentral dependency sync ok, but symbol cannot be resolved

So, I managed to create an Android library component and publish it on Maven Central. But when I'm trying to use it as a dependency in a new project, Android Studio can't seem to find the classes.
build.gradle for the app module:
repositories {
mavenCentral()
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:21.0.3'
compile 'no.hyper:libdateintervalpicker:1.0.0' //this is the one I want to use
}
This part seems to work, at least I get no sync errors. However, when trying to access to package and classes from my MainActivity, Android Studio can't find them and gives me "cannot resolve symbol" message.
I have tried downloading the classes.jar from the archive directly from Maven Central, and they are indeed in the package.
Other dependencies seem to appear in the /build/intermediates/exploded-aar folder after syncing, but that does not happen to my library.
I use Android Studio 1.0.2 on OSX 10.9.5 (Mavericks)
Any suggestions?

Looking in your pom, it states <packaging>aar.asc</packaging>. It should be aar instead.

Oh, and the answer to actually being able to use the library, was to add #aar to the dependency so that it now reads
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:21.0.3'
compile 'no.hyper:libdateintervalpicker:1.0.0#aar' //note the magic #aar
}
Edit:
Removing the block
configurations {
archives {
extendsFrom configurations.default
}
}
makes Gradle generate the pom with the correct packaging entry, and thus makes it possible to reference the dependency without the #aar suffix

Avoid packing .jar into Android Library (.aar)

My project is an Android Library which depends on Dropbox's android library.
dependencies {
...
provided fileTree(dir: '../Libraries/Dropbox', include: ['*.jar'])
...
}
Everything works well excepts Gradle puts all the .jar files from Dropbox into my output .aar file.
MyLib.aar
|-classes.jar
|-AndroidManifest.xml
|-...
|-libs
|-bcprov-jdk16-146.jar
|-commons-logging-1.1.1.jar
|-dropbox-android-sdk-1.6.1
|-json_simple-1.1.jar
How can I avoid this?

something like this might help you:
android.libraryVariants.all { variant ->
variant.outputs.each { output ->
def packageLib = output.getPackageLibrary()
packageLib.exclude('libs/externalLibrary.jar')
}
}
inside android {} block

Why do you want to avoid this? When you give your library to someone, they have all the dependencies already in one file.
You can include the dependencies via
compile 'com.dropbox.core:dropbox-core-sdk:1.7.7'
compile 'com.googlecode.json-simple:json-simple:1.1.1'
compile 'commons-logging:commons-logging:1.2'
compile 'org.bouncycastle:bcprov-jdk16:1.46'
in your build.gradle file and remove it from the libs folder. Do the same with the other dependencies. This way they will not be packaged into your .aar file.

Can't add External Library in Android Studio?

I Added a External Library to my project by following
this method. and tried this method too this method too.
Gradle build got Finished and i got this line added to my build.gradle
compile 'com.github.castorflex.smoothprogressbar:library-circular:1.0.1'
Now i am trying to import this library in my class. But i can't do this. I took a look at the files and they are located in the build directory under the exploded-aar. so i added #aar to the compile line. Still there are no changes.
How can i import this library to my class or where i am going wrong?
Thanks in Advance

Well, you don't need to download anything or point your dependency to a file.
This dependency, as most of the dependencies you use, can automatically fetched from JCenter, biggest repository for Java and Android components.
All you need to do is:
Add JCenter as your dependencies repository.
Declare that you need the library-circular dependency. This can be found and copy/pasted from the file icon in particular package/version in JCenter.
Resync your Android Studio project with your Gradle build file. This is the 'sync' button in Gradle pane in Android Studio.
Here's what your build.gradle should include:
repositories {
jcenter()
}
dependencies {
compile(group: 'com.github.castorflex.smoothprogressbar', name: 'library-circular', version: '1.0.1', ext: 'aar')
}

in build. gradle put following code
dependencies {
compile fileTree (dir: 'libs', include: ['*.jar'])
}

Did you add the dependencies?
You can do so in the following way -
dependencies {
compile files('insert ParentFolder/external_library_name with the extension here')
}
Add it to build.gradle based in the app folder

1.Put the jar file into the libs folder.
2.Right click it and hit 'Add as library'.
3.Ensure that compile files('libs/abcdef.jar') is in your build.gradle file and Finally add the dependencies.
Eg.
dependencies {
compile fileTree(dir: '../jar', include: '*.jar')
compile project(':pull-to-refresh')
compile files('libraries/abcdef.jar')
}
Hope this helps :)