Develop Reference

Android Studio Gradle Sync Error using google play-services-maps 11.6.2

I am developing a google map app using Android Studio. When I sync the project with Gradle Files (Select Tools/Android/Sync Project with Gradle Files on Android Studio), I get the following error:
Could not resolve com.google.android.gms:play-services-maps:11.6.2.
Couold not get resource 'https://dl.google.com/dl/android/maven2/com/google/android/gms/play-services-maps/11.62./play-services-maps-11.6.2.pom
This is the software I am using:
Android Studio 3.0.1
Android Version 7.1.1
Google Play Services 46
Google Repository 58 (under Support Repository)
I've tried using both the google maps project template and the empty activity project but I get the same error.
I am using the http proxy setup I used from earlier projects. I am able to install the play-services-maps and the google repository.
I also added the maven url to the Gradle Project file in the All Projects/Repositories section.
I have tried the suggestions from Stack Overflow but none have not worked.
Any ideas?
Gradle Project Build file:
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
maven {
url "https://maven.google.com"
}
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
The gradle app build file:
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
defaultConfig {
applicationId "hansen.scott.googlemaps"
minSdkVersion 25
targetSdkVersion 26
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
implementation 'com.google.android.gms:play-services-maps:11.6.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}
The error is in the line:
implementation 'com.google.android.gms:play-services-maps:11.6.2'

try adding this in project level gradle file
allprojects {
repositories {
maven {
url "https://maven.google.com"
}
}
}

Someone had the same issue I did and entered it on Stack Overflow a day or two ago. The user was getting a build error when using player-services-maps 11.6.2. If the user changed the version to 11.0.0, the build succeeded.
Once I back-dated the maps version to 11.0.0, this solved my problem too. I created a new Google Map project and didn't modify the Gradle Build files.
The problem appears to be that play-services-maps won't build using a versions after 11.0.0. I will post the issue on Github.
Thank you for everybody's help.

I have been facing the same issue for the past one week and posted it on Stack Overflow as well but to no effect.
I have since then figured out the root cause. I am working out of my office and thus have firewalls in place. I got it checked with the system admin and on turning off the firewall the build worked.
So i would advice you to have this checked as well.
Kind regards,
Kabir

Getting .dex 64K error on a small app that works fine on a different PC

I've recently started a new Android Studio project on one PC (very barebones: 3 Activitys, 1 Fragment, all very basic at this stage), and uploaded it to Version Control System through Android Studio (I assume it will only add the necessary files).
When I checkout the project on a different PC, Android Studio recognizes it is a project, and offers to open it as one. The gradle build completes, but on attempting to run the app on a device or emulator, I get the old problem:
Error: The number of method references in a .dex file cannot exceed 64K.
The only dependency as such is the 'bluealliance spectrum color picker', which I have used in the past without issue. I would assume that it has built something wrong, but considering everything is identical to the original project I can't see how it's going wrong - or how it could possibly have >64K methods.
Below are the gradle files:
mobile build.gradle:
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "24.0.1"
defaultConfig {
applicationId "com.aetherum.timetableapp"
minSdkVersion 19
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
repositories {
maven {
url "http://github.com/wada811/Android-Material-Design-Colors/raw/master/repository/"
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.thebluealliance:spectrum:0.6.0'
compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.google.android.gms:play-services:9.4.0'
compile 'com.android.support:design:23.4.0'
compile 'com.android.support:preference-v7:23.2.1'
compile 'com.android.support:preference-v14:23.2.1'
compile 'com.wada811:android-material-design-colors:2.0.0'
}
And the project build.gradle :
buildscript {
repositories {
jcenter()
maven {
url "https://plugins.gradle.org/m2/"
}
}
dependencies {
classpath 'com.android.tools.build:gradle:2.1.2'
classpath 'com.github.dcendents:android-maven-gradle-plugin:1.3'
classpath "com.jfrog.bintray.gradle:gradle-bintray-plugin:1.6"
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
jcenter()
flatDir {
dirs 'libs'
}
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
I have tried cleaning and rebuilding the project, as well as checking it out again from git. At this stage, as an inexperienced developer, I'm out of ideas.

The only dependency as such is the 'bluealliance spectrum color picker',
No, you have at least seven dependencies, not including any JARs that might be in libs/.
One of those dependencies is play-services. Unless you are using every single API in the Play Services SDK, you will be much better off using more granular dependencies (e.g., play-services-maps for Maps V2), to pull in only those bits of Play Services that you need.
BTW, you should change your 23.2.1 dependencies to 23.4.0, so all your Android Support Library dependencies are from the same version.

Please remove this line of code
compile 'com.google.android.gms:play-services:9.4.0'

Cannot change dependencies of configuration (after enabling instant run)

I just enabled instant run in my android studio project. (Followed the instructions here)
My project contains git submodules and somehow these do not compile anymore.
This is the error i get:
Error:(8, 0) Cannot change dependencies of configuration
':libraries:my_library:classpath' after it has been resolved.
Any idea what could be wrong there ?
Top level build.gradle:
buildscript {
repositories {
mavenCentral()
jcenter()
maven { url 'https://maven.fabric.io/public' }
}
dependencies {
classpath 'com.android.tools.build:gradle:2.0.0-alpha1'
classpath 'com.novoda:bintray-release:0.2.7'
classpath 'io.fabric.tools:gradle:1.+'
}}
Module build.gradle:
apply plugin: 'android'
apply plugin: 'io.fabric'
android {
defaultConfig {
versionCode 4850
versionName '4850'
compileSdkVersion 23
buildToolsVersion '23.0.1'
}
packagingOptions {
exclude 'META-INF/LICENSE'
exclude 'META-INF/MANIFEST.MF'
exclude 'META-INF/NOTICE'
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_7
targetCompatibility JavaVersion.VERSION_1_7
}
useLibrary 'org.apache.http.legacy'
}
repositories {
mavenCentral()
jcenter()
}
dependencies {
[skip]
compile project(':libraries:my_library:sdk')
}
Library build.gradle
apply plugin: 'com.android.library'
android {
compileSdkVersion 23
buildToolsVersion '23.0.2'
defaultConfig {
minSdkVersion 14
targetSdkVersion 23
}
lintOptions {
abortOnError false
}
}
repositories {
mavenCentral()
}
dependencies {
compile fileTree(include: '*.jar', dir: 'libs')
compile 'com.android.support:support-v4:23.1.0'
compile 'com.android.support:appcompat-v7:23.1.0'
testCompile 'junit:junit:4.12'
}

gradle reads and executes all build.gradle files in all folders of the included modules. As the error shows, it also tries to execute the root build script of :libraries:my_library.
You have to change your settings.gradle and include the library project by setting its 'projectDir':
include ':app'
// Give your library project any module name, i.e. ':sdk'
include ':sdk'
// Then set the project path of the library module
project(':sdk').projectDir = new File('libraries/my_library/sdk')
With this settings.gradle you can reference the library project as gradle dependency with:
compile project(':sdk')

I had the same problem. I resolved it by removing the classpath in the submodule Top-level build.gradle file.
dependencies {
// classpath 'com.android.tools.build:gradle:1.0.0'
}
I'm not sure if it's the best thing to do, but it worked for me.

I had the same problem. I compared it to the (working) sample project by #RaGe and found the minor difference.
The sub project folder has to start with a Upper case letter.
Here is the change I did on #RaGes sample to break it and get it working again.
Broken structure:
android-multi-project-sample
+ .gralde
+ .idea
+ app
+ build
+ gradle
+ myApplication2
- .gitignore
- android-multi-project-sample.iml
- build.gradle
- gradle.properties
- gradlew
- gradlew.bat
- local.properties
- settings.gradle
results in the following error:
Error:(8, 0) Cannot change dependencies of configuration ':myApplication2:classpath' after it has been resolved.
Working structure (with upper case sub project)
android-multi-project-sample
+ .gralde
+ .idea
+ app
+ build
+ gradle
+ MyApplication2 // upper case!!!!!!
- .gitignore
- android-multi-project-sample.iml
- build.gradle
- gradle.properties
- gradlew
- gradlew.bat
- local.properties
- settings.gradle
also the top level settings.gradle has to be changed:
+ include ':app', ':MyApplication2:mylibrary'
- include ':app', ':myApplication2:mylibrary'
and app/build.gradle has to change this
+ compile project(':MyApplication2:mylibrary')
- compile project(':myApplication2:mylibrary')
Everything compiles
Be careful! Git is not case sensitive by default. Use
git mv -f myApplication2 temp
git mv -f temp MyApplication2
to rename the folder.

According to official documentation on instant run.
What happened behind the scenes is that we have updated your project’s build.Gradle file to use the latest version of the Android Gradle plug-in, which is required for Instant Run to work. We also update your Gradle wrapper version to 2.8, and attempt to update the build tools version in all your modules to the latest (23.0.2). This isn't required for Instant Run, but it will use a new faster version of dex, which helps both instant run and a full build be a bit faster.
A Snippet of Application\build.gradle is shown below:
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.0.0-alpha1'
}
}
Known Issues Using Instant Run
Using Instant Run with Reflection
Reflection could show unexpected things, for example:
Classes are all made public
Many other things are also made public
Limitations with Performance Profiling
We suggest temporarily disabling Instant Run while profiling your debug application.
There is a very small performance impact when using Instant Run, and a slightly larger impact when methods are overridden.
Increases in App Methods
Instant Run adds some methods–140 plus three times the number of classes in your app and its local dependencies. If the app was previously just below the dex limit, enabling Instant Run may push your app over the dex limit. Learn how to fix this by Optimizing Multi dex Development Builds.
Other Known Issues
Intermittent issues may occur where the IDE loses connection with the app which will trigger a full rebuild.
Third party Gradle plugin compatibility has not yet been tested, especially those that have not been updated to use the new transforms API.
Data-binding is currently broken in this build (capability to be restored).
so if you are facing this issue then you can turn off you instant run
go to Settings → Build, Execution, Deployment → Instant Run and uncheck Enable Instant Run… .
Better understanding of instant run go here

Take your dependencies out of your top level build gradle. As it is you are creating a classpath with your top level gradle and then attempting to overwrite it with your other build.gradles
From:
buildscript {
repositories {
mavenCentral()
jcenter()
maven { url 'https://maven.fabric.io/public' }
}
dependencies {
classpath 'com.android.tools.build:gradle:2.0.0-alpha6'
classpath 'com.novoda:bintray-release:0.2.7'
classpath 'io.fabric.tools:gradle:1.+'
}}
To: Note I did not add that commented line, Android-Studio does this automatically
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.0.0-alpha6'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
jcenter()
}
}
You should be able to add any needed Maven repositories into your separate app gradles, as they should be specific and the jcenter would cover many of these, as #AndroidMechanic, and #Hi I'm Frogatto have been trying to say in previous answers and comments.
Have a look at read here Bintray - JCenter
The other thing is, I do not understand why you are managing your libraries build gradle within your project as part of your project. You should be referencing your library from your project, with the app build.gradle. You are treating the library gradle as the app gradle.
dependencies {
compile fileTree(include: '*.jar', dir: 'libs')
compile 'com.android.support:support-v4:23.1.0'
compile 'com.android.support:appcompat-v7:23.1.0'
testCompile 'junit:junit:4.12'
}
Make these changes, then see what duplicates and you can manage that from there.
Also, I recommend manually syncing project with gradle files when changes are made. I would not rely on instant anything, it's important to make changes step wise and take stock of what's occurring, particularly when it won't compile. That's my opinion only and one way to program in android.
If instant run creates havoc with a particular project, I would disable it for that project. It is enabled by default and I've had no issues with it. The build mess may be the result of unclear gradles in your project to begin with.
Also:
In gradle wrapper properties, grade 2.10 is required for classpath 'com.android.tools.build:gradle:2.0.0-alpha6':
distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip
See here for latest updates
Android Tools Project Site
Or you can install a previous version of Android Studio and use the previous working version of your project.
If you have multiple git files, I suggest you remove the redundant ones, keep only the ones you are using for version control.

classpath 'com.android.tools.build:gradle:2.0.0-alpha1'
try to change it to
classpath 'com.android.tools.build:gradle:2.0.0-alpha6'
alpha1 seems obsolete since today (?) and is not compiling any more.
Also you'll have to upgrade your gradle to latest 2.10 to work with alpha6

Two things you can try
Change your plugin for "android"
With the new gradle tools you need to specify the correct plugin for your module gradle file as well as your library gradle file. If you look closely, your library gradle file is correct:'
apply plugin: 'com.android.library'
Change your module gradle plugin:
apply plugin: "android" -> apply plugin: 'com.android.application'
org.apache classes are now depcrated
This could also be a possible reason as to why your application isn't compiling anymore. Remove this:
useLibrary 'org.apache.http.legacy'
See Deprecated List.

The library project's build.gradle seems to cause the configuration error (because of some obscure reason). For me it was enough to also add the library project (which is a git submodule) to settings.gradle instead of only adding the library's project module.
Instead of:
include ':libraries:my_library:sdk'
try including both the library subproject and the subproject's module:
include ':libraries:my_library'
include ':libraries:my_library:sdk'

jitpack.io failed to resolve github repo

I have a Github repo and pushed tags on it.
This is my gradle file of my main project.
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.0"
defaultConfig {
applicationId "dropbox.ric.es.myapplication"
minSdkVersion 16
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
repositories {
//mavenCentral()
//jcenter()
maven { url "https://jitpack.io" }
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.github.rchampa:DropboxHttpConector:1.0.1'
}
But when I sync gradle I have the following error Failed to resolve com.github.rchampa:DropboxHttpConector:1.0.1
Another attempt:
allprojects {
repositories {
jcenter()
maven { url "https://jitpack.io" }
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.github.rchampa:DropboxHttpConector:1.0.1'
}
Still failing.

For anyone else that made the simple mistake I made:
Ensure you add the maven { url "https://jitpack.io" } under allprojects instead of buildscript.
Project build.gradle file:
buildscript {
repositories {
jcenter()
// DO NOT ADD IT HERE!!!
}
...
}
allprojects {
repositories {
mavenLocal()
jcenter()
// ADD IT HERE
maven { url "https://jitpack.io" }
}
}
Thanks to Alexander Pacha for pointing that out in a comment above.

Newer versions of Android Studio don't use allprojects anymore.
Open the file settings.gradle and add the repository as shown below:
dependencyResolutionManagement {
repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
repositories {
google()
mavenCentral()
maven { url 'https://jitpack.io' } // <- here we go
jcenter()
}
}
Also remove the code below from the file project's build.gradle, if it is still there:
allprojects {
repositories {
jcenter()
maven { url "https://jitpack.io" }
}}

After a few attempts and thanks to jitpack support now I can import my library hosted in Github as a Android Gradle dependency.
I will provide a a few very useful links:
How setup your java library
https://jitpack.io/docs/BUILDING/#gradle-projects
How check logs of your dependency in jitpack
https://jitpack.io/com/github/USER/REPO/TAG/build.log
In my case
https://jitpack.io/com/github/rchampa/DropboxHttpConector/1.0.3/build.log

I have several dependencies from Jitpack and I encountered this issue after migrating to Gradle 2.
The solution in my case was to change the version in distributionUrl in gradle-wrapper.properties from 2.10 (which was automatically set by Studio when I accepted updating the wrapper version) to the latest one.

Hallelujah I got the problem!
So I realised that PROBLEM is relied on my NETWORK! I can't acces https://jitpack.io/ from my IP that's why nothing was working. Just shared internet from a GSM module(to get a different IP) and problem is gone using #SteveMellross solution
Maybe it can be 0.001% that you have the same problem but if nothing works just try to access https://jitpack.io/ ;)
I hope there is just a firewall or internal router error and my IP is not banned by their service.

Verify that maven { url "https://jitpack.io" } is in allprojects section in build.gradle (Project)

For me I did this
1.Forked the original unmaintained repo
2.Did some changes,created the commit
3.Copied commit hash from commit details page url
eg https://github.com/omkar-tenkale/NavigationTabStrip/commit/9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0
4.Created implementation string from repo url
implementation 'com.github.User:Repo:Version'
Group: com.github.Username
Artifact: Repository Name
Version: Release tag, commit hash or master-SNAPSHOT
More at https://github.com/jitpack/jitpack.io
I used commit hash as Version
implementation
'com.github.omkar-tenkale:NavigationTabStrip:9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0'
5.Now added that in android app module's build gradle
6.But got error Unable to resolve dependency for ':app#debug/compileClasspath': Could not resolve...etc
7.Created a link in below format
https://jitpack.io/com/github/USER/REPO/TAG/build.log
In my case
https://jitpack.io/com/github/omkar-tenkale/NavigationTabStrip/9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0/
8.Opened this link in browser
9.Saw something like this
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0-javadoc.jar
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0-sources.jar
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0.aar
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0.pom
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0.pom.md5
NavigationTabStrip-9d097af9fe2167fc0dfc71d2e63d6194b2cebfb0.pom.sha1
build.log
In studio synced gradle again
It worked!
This is far better then downloading repo,importing as module in our app and then using it etc etc.
Whenever you make changes to this forked repo don't forget to update commit hash too!

I meet this problem when I try to import orhanobut/logger from github.
Then I go to jitpack.io and search for the package:
find logger in jitpack
Then I clicked the log icon,and found:
Start: Thu Jan 14 11:56:56 UTC 2016
Git:v1.9
commit 5abbc1563422457d4c23e1a0a412d2b0c7dc334e
Merge: 8ef1e6b 522d44d
Author: Orhan Obut
Date: Mon May 25 11:34:20 2015 +0200
Merge pull request #30 from orhanobut/oo/settings-fix
submodule status:
Run gradle build
Gradle build script
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
Downloading https://services.gradle.org/distributions/gradle-2.2.1- all.zip
So this is it,it use gradle 2.2.1-all!
Then I go to my project and change gradle version to 2.2.1 in settings.gradle, everything worked fine!

I'm using Android Studio Arctic Fox 2020.3.1 | Canary 8 and had the issue above.
My repo project is a pure Kotlin project that I want to import into my Android project.
Here are a few steps I did that fixed the issue for me - it could be one of the steps or a combination of them that fixed the issue.
The tag I initially pushed was v0.0.1 but in my build.gradle for the Kotlin project it was version '0.0.1' without the v. So I renamed the tag to 0.0.1 and pushed the tag. #Ricardo's answer above about how to check the JitPack build log was super useful!
Next I ran ./gradlew install on my local machine in the Kotlin repo. This is one of the commands run by JitPack - see the JitPack documentation. When I did this I found this message: Declare the version of Java your build requires.
From that message I decided to specify the Java version. In the Kotlin project build.gradle I added sourceCompatibility = 1.8 and
compileKotlin {
kotlinOptions {
jvmTarget = "1.8"
}
}
After re-running the command in step 2, the Java version issue disappeared.
I pushed the new version of my Kotlin repo and added a new tag.
In the Android project, I had to add the maven { url "https://jitpack.io" } in settings.gradle. I encountered errors when adding it in the build.gradle files for the app or the root one.

I know this is old but I had this problem recently and I solved it by adding
maven { url 'https://jitpack.io' }
to the settings.gradle(ProjectSettings) under dependencyResolutionManagement{repositories{$HERE}}. I don't know if it is recommended or just a fluke since I am not that well versed yet.

Adding local .aar files to my gradle build

So I have created an Android library and successfully compiled it into a .aar file. I called this aar file: "projectx-sdk-1.0.0.aar". Now I want my new project to depend on this aar so what I have done is follow this post.
But the post confuses me since I do not get the desired result:
The package name of the aar is : com.projectx.photosdk and the module inside is called sdk
Here is my current project structure:
|-SuperAwesomeApp
|--.idea
|--gradle
|--App
|---aars
|----projectx-sdk-1.0.0.aar
|---build
|---jars
|---src
|---build.gradle
And here is my Gradle build file:
apply plugin: 'android'
buildscript {
repositories {
mavenCentral()
flatDir {
dirs 'aars'
}
}
}
android {
compileSdkVersion 19
buildToolsVersion "19.0.1"
defaultConfig {
minSdkVersion 11
targetSdkVersion 19
versionCode 1
versionName "1.0"
}
buildTypes {
release {
runProguard false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
}
}
}
dependencies {
compile 'com.android.support:gridlayout-v7:19.0.1'
compile 'com.android.support:support-v4:19.0.1'
compile 'com.android.support:appcompat-v7:19.0.1'
compile 'com.projectx.photosdk:sdk:1.0.0#aar'
// compile files( 'aars/sdk-1.0.0.aar' ) // Does not work either
}
EDIT
The errors I am getting:
Failed to refresh Gradle project 'SuperAwesomeApp'
Could not find com.projectx.photosdk:sdk:1.0.0.
Required by:
SuperAwesomeApp:App:unspecified

You put your flatDir block in the wrong repostories block. The repositories block inside buildscript tells Gradle where to find the Android-Gradle plugin, but not the rest of the dependencies. You need to have another top-level repositories block like this:
repositories {
mavenCentral()
flatDir {
dirs 'aars'
}
}
I tested this and it works okay on my setup.

With recent versions of Android Studio, tested with 1.3, to use local .AAR file and not one fetched from maven/jcenter repository, just go to File > New > New module and choose Import .JAR/.AAR Package.
What you will end up with is a new module in your project that contains very simple build.gradle file that looks more or less like this:
configurations.create("default")
artifacts.add("default", file('this-is-yours-package-in-aar-format.aar'))
Of course, other projects have to reference this new module with regular compile project directive. So in a project that uses this new module which is simple a local .aar file has this in it's build.gradle
[...]
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.1.0'
compile 'com.android.support:design:23.1.0'
[...]
compile project(':name-of-module-created-via-new-module-option-described-above')
}
[...]

In Android Studio 3.1.3 with gradle 3.0.1.
Simply adding implementation fileTree(dir: 'libs', include: ['*.aar']) or implementation files('libs/app-release.aar') without any other flatdir works.

These days (over 1 year after this question) with Android Studio >1.0, local dependency does work properly:
The android sdk looks for dependencies in a default local repo of: $ANDROID_HOME/extras/android/m2repository/
In a local library project you can publish the aar to this directory. Here's a snippet that can be added to your module's build.gradle file (ex: sdk/build.gradle)
apply plugin: 'maven'
uploadArchives {
repositories {
mavenDeployer {
repository(url: "file://localhost" + System.getenv("ANDROID_HOME")
+ "/extras/android/m2repository/")
pom.version = '1.0-SNAPSHOT'
pom.groupId = 'your.package'
pom.artifactId = 'sdk-name'
}
}
}
some reference gradle docs http://gradle.org/docs/current/userguide/artifact_management.html
In your library project, run ./gradlew uploadArchives to publish the aar to that directory
In the application project you want to use the library in, add the dependency to your project/app/build.gradle. compile 'your.package:sdk-name:1.0-SNAPSHOT'
For local dependency, the next gradle build should find the previously deployed archive and that's it!
In my case, I use the above for local dev, but also have a Bamboo continuous integration server for the Library that publishes each build to a shared Nexus artifact repository. The full library code to deploy the artifact then becomes:
uploadArchives {
repositories {
mavenDeployer {
if (System.getenv("BAMBOO_BUILDNUMBER") != null) {
// Deploy to shared repository
repository(url: "http://internal-nexus.url/path/") {
authentication(userName: "user", password: "****")
}
pom.version = System.getenv("BAMBOO_BUILDNUMBER")
} else {
// Deploy to local Android sdk m2repository
repository(url: "file://localhost" + System.getenv("ANDROID_HOME")
+ "/extras/android/m2repository/")
pom.version = '1.0-SNAPSHOT'
}
pom.groupId = 'your.package'
pom.artifactId = 'sdk-name'
}
}
}
In order to tell applications to download from my internal Nexus repository, I added the internal Nexus maven repository just above jcenter() in both "repositories" blocks in the project/build.gradle
repositories {
maven {
url "http://internal-nexus.url/path/"
}
jcenter()
}
And application dependency then looks like compile 'your.package:sdk-name:45' When I update the 45 version to 46 is when my project will grab the new artifact from the Nexus server.

With the newest Gradle version there is now a slightly updated way of doing what Stan suggested (see maving publishing)
apply plugin: 'maven-publish'
publishing {
publications {
aar(MavenPublication) {
groupId 'org.your-group-id'
artifactId 'your-artifact-id'
version 'x.x.x'
// Tell maven to prepare the generated "*.aar" file for publishing
artifact("$buildDir/outputs/aar/${project.getName()}-release.aar")
}
}
repositories {
maven {
url("file:" + System.getenv("HOME") + "/.m2/repository")
}
}
}

It seems adding .aar files as local dependency is not yet supported(Planned to be supported in 0.5.0 Beta)
https://code.google.com/p/android/issues/detail?id=55863
But the way you are using your library in dependency will only work if your library is on central maven repository or in the local maven repository.
Refer this for How to use local maven repository to use .aar in module dependencies.
http://www.flexlabs.org/2013/06/using-local-aar-android-library-packages-in-gradle-builds

This is for Kotlin DSL (build.gradle.kts) assuming you put the files in my-libs subdirectory relative to where the build file is located:
dependencies {
implementation(
fileTree("my-libs/") {
// You can add as many include or exclude calls as you want
include("my-first-library.aar")
include("another-library.aar")
// You can also include all files by using a pattern wildcard
include("*.jar")
exclude("the-bad-library.jar")
}
)
// Other dependencies...
}
For more ways to do this, see Gradle documentations and this post and this post.