Using library android studio

Содержание
  1. How to use android libraries locally and leaving your development faster
  2. 1. Create new project with sample module
  3. 2. Create the library module
  4. 3. Importing the module created in an external project locally
  5. 3.1 Include module folder into project
  6. How to Add a Library Project to Android Studio?
  7. Different Ways To Add Library Project to Android Studio
  8. Method 1
  9. Method 2
  10. Method 3
  11. Method 4
  12. daniellevass / starting_library_project_AS.md
  13. Add build dependencies
  14. Dependency types
  15. Groovy
  16. Kotlin
  17. Groovy
  18. Kotlin
  19. Groovy
  20. Kotlin
  21. Groovy
  22. Kotlin
  23. Groovy
  24. Kotlin
  25. Groovy
  26. Kotlin
  27. Native dependencies
  28. Dependency configurations
  29. Groovy
  30. Kotlin
  31. Deprecated Gradle configurations (available in AGP 1.0–4.2)
  32. Groovy
  33. Kotlin
  34. Groovy
  35. Kotlin
  36. Groovy
  37. Kotlin
  38. Add annotation processors
  39. Groovy
  40. Kotlin
  41. Pass arguments to annotation processors
  42. Groovy
  43. Kotlin
  44. Groovy
  45. Kotlin
  46. Groovy
  47. Kotlin
  48. Disable the annotation processor error check
  49. Groovy
  50. Kotlin
  51. Groovy
  52. Kotlin
  53. Exclude transitive dependencies
  54. Groovy
  55. Kotlin
  56. Exclude transitive dependencies from test configurations
  57. Groovy
  58. Kotlin
  59. Configure Wear OS app dependencies
  60. Groovy
  61. Kotlin
  62. Groovy
  63. Kotlin
  64. Remote repositories
  65. Groovy
  66. Kotlin
  67. Groovy
  68. Kotlin
  69. Groovy
  70. Kotlin
  71. Google’s Maven repository
  72. Groovy
  73. Kotlin
  74. Groovy
  75. Kotlin
  76. Programmatic access
  77. Offline repository from SDK Manager
  78. Native dependencies with the Android Gradle plugin
  79. Using native dependencies
  80. Native dependencies in AARs
  81. Build system configuration
  82. Groovy
  83. Kotlin
  84. Publishing native libraries in AARs
  85. Groovy
  86. Kotlin
  87. Dependency order
  88. View module dependencies
  89. Fix dependency resolution errors
  90. Fix duplicate class errors
  91. Fix conflicts between classpaths
  92. Apply custom build logic
  93. Publish variant dependencies to custom logic
  94. Custom dependency resolution strategies
  95. Groovy
  96. Kotlin
  97. Dependency information for Play Console

How to use android libraries locally and leaving your development faster

In android development we have a problem that makes us a little frustrated every day, the build time . The android studio build time has a tendency to increase with each day that our project is getting bigger, with that isolating everything we will have in the one project, in a single module, and this is an option that is not so interesting, both to avoid rewriting code in a future project, both to avoid creating a liability relationship of some common feature .

One option for us to try resolve this is to create libraries, which are nothing more than independent modules which has an easy integration and has its responsibility defined and isolated, avoiding side effects and being portable for numerous cases.

To use this portability we need to take a few steps:

  1. Creating new project with sample module
  2. Creating the library module
  3. Importing the module created in an external project
  4. Sharing with community .

I am writing listening a brazilian band called Bullet Bane, in my posts i like share music in view of my great musical passion and the responsibility to disseminate more music around the world. So Let’s go code ..

1. Create new project with sample module

Creating libraries is a task that can be done at any time and in the way that you think necessary, my suggestion is to create them in an external project and thus removing any possibility of interdependence, enabling it to develop outside the scope of only one project and too create one identity to a common feature. So let’s go with my suggestion, create the new android project ..

With the new project created and its initial structure simple, with MainActivity and everything else, we will determine that this App module will be our sample module, which will be used to test the integration of our library, if you want rename the “App” module to “Sample” .

2. Create the library module

To create is a simple task, in Android Studio each library is a module. To create a new library module in Android Studio, select File ▸ New ▸ New Module and select Android Library .

When we create the library it is not automatically imported into our sample module, so simply go to the build.gradle of our sample module and add in the dependencies :

With this we can develop our feature in this created library module, with all its responsibilities much more clear, specific and without any complexity of a great project, without mentioning that clearly the build time of our sample module destined to be our workspace of this library is much faster than our main project. A great suggestion is also to add integration tests in the sample module and unit tests in your library module to ensure that it develops with complete security and consistence of its main and future functionalities.

3. Importing the module created in an external project locally

This task can be done automatically by Android Studio, but my suggestion is that you do it manually so that you understand the process clearly and can fit in case you need it.

3.1 Include module folder into project

Automatically is simple only in Android Studio, select File ▸ New ▸ Import Module and write path of library project and select only library module .

Manually it’s more cool, despite having to write some more but i think it more interesting to eliminate any magic that IDE makes and to facilitate understanding the process. Steps below ..

Источник

How to Add a Library Project to Android Studio?

Adding an external library in Android Studio is a very common thing but still, most beginners or freshers find it difficult to do. Some of you must have gone through this. Whenever you want to add some external library and you try to do that with maven(File > Project Structure > Dependencies) and try to add your dependencies there but when you hit Gradle sync, it fails. So now, without fixing this, you want to go for building your app then you will get the error: Error: A problem occurred configuring project ‘:app’. There are many external libraries available that make many specific tasks simple and easy with the APIs and Classes they provide. So including all those libraries in our project is really going to help you a lot. Many developers are often confused about how to add these libraries to their projects. This article is helpful for all such people.

In this article, we will see different ways to add library projects to our project. But before jumping to that let’s have a quick look at this: We can use Gradle, to add library projects with a single line code. Android Studio Project has a modular structure and we have a main module called “app”. There may be multiple modules in a Project. We can connect them together through Gradle, this connection is known as Dependency. Now Let’s get back to our main agenda.

Different Ways To Add Library Project to Android Studio

Method 1

Almost every well-known Android library is available in a Maven repository and its installation takes only one line of code in the app/build.gradle file:

Let’s add the external library to our project:

Step 1: Create a new project using Android Studio and name it anything you want (GFG in this example) and hit the finish button.

Step 2: The original project structure created by Android Studio looks like this:

Step 3: In the root directory (GFG/), create a new folder: /libs in which we’ll place our external libraries (this step is not required – only for keeping a cleaner project structure).

Step 4: Paste your library in the newly created /libs folder. For this example, we are using the PagerSlidingTabStrip library (you just need to download ZIP from GitHub, rename the library directory to “PagerSlidingTabStrip” and copy it). The new structure of our project should look like this:

Step 5: Edit settings.gradle by adding your library to include. If you use a custom path like I did, you have also to define the project directory for our library. A whole settings.gradle should look like below:

project(‘:PagerSlidingTabStrip’).projectDir = new File(‘libs/PagerSlidingTabStrip’)

Step 5.1: If you face “Default Configuration” error, then try this instead of step 5,

Step 6: In app/build.gradle add our library project as a dependency:

compile fileTree(dir: ‘libs’, include: [‘*.jar’])

Step 6.1: If you followed step 5.1, then follow this instead of 6,

compile fileTree(dir: ‘libs’, include: [‘*.jar’])

Step 7: If your library project doesn’t have build.gradle file you have to create manually.

Step 8: That’s all. Just click‚ synch the project with Gradle. Your library should be available for your project.

Method 2

Step 1: Follow to File > New Module

Click on “Import Existing Project“.

Step 2: Select the desired library and the desired module. Then click finish. Android Studio will import the library into your project and will sync Gradle files.

Step 3: In the next step you need to add the imported module to your project’s dependencies. Right-click on the app folder > Open Module settings

Step 4: Navigate to the dependencies tab > Click on the ‘+’ button -> click on Module Dependency. The library module will be then added to the project’s dependencies.

Method 3

Step 1: Navigate to File > Project Structure

Step 2: Then click on Modules.

To import the library using Gradle, you can have to add it to the dependencies section of your build.gradle (the module’s one).

Method 4

Just go to Project Structure > under Modules (see below images) just click the plus button and select Import Existing Project and import. Then sync your Gradle files. There are chances to face the error

Error: The SDK Build Tools revision (xx.x.x) is too low. Minimum required is yy.y.y

Then just open the build.gradle file in your library project directory and update the buildToolsVersion to the suggested one.

then try importing the module by clicking on File > Project Structure

Module > Import Module

After importing the library module, select your project module and add the dependency and then select the imported module.

Источник

daniellevass / starting_library_project_AS.md

Getting Started with a library project in Android Studio

So we’re working on creating Android Material Awesome, a library which will hopefully incorperate the benefits of Material Design, Twitter’s Bootstrap, and FontAwesome. What we really wanted is a project other people can easily include into their projects using gradle dependencies. To do this we needed to create a standalone library project so we could make it as lightweight as possible for including as a dependency, and a sample app that would use it for testing. These are the steps we took to get started in Android Studio (version 1.1).

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The first thing we needed to do was to create two new projects, with all the default settings (Blank Activity etc). One for our sample app, and one for our library. We added both of ours into the same GitHub repo, however you can save them wherever you like.

Fix Up Library Project

####1. Rename Module

Initially we’ll focus on our library project. Annoyingly Android Studio automatically creates you a module called app . Modules really should be uniquely named, so you’ll need to right click on the module name, click refactor and rename to something useful. We called ours library .

####2. Rename Folder

Unfortunately, this doesn’t fully rename the root folder. So using Finder (OS X) or File Explorer (Windows), you’ll need to navigate to the module folder. Rename it to match what you named your module you named it e.g. library .

Android Studio calls my module library, but Finder still says app

####3. Drag build.gradle into Android Studio

This’ll break your project! To fix it, you need to go back to Android Studio, and open the build.gradle for the module. It’ll have a little warning at the top asking you to add it to the project. Click this and wait for gradle to synchronise again! All your files should magically reappear again!

Drag the highlighted file back into Android Studio

You should see a yellow/gold banner appear at the top of your file, click it to add file to your project and wait for Android Studio to synchronise. Once it’s done, you should see all your files have magically reappeared again!

click the yellow/gold banner at the top to add file to project and synchronise

####5. Make Android Library

Whilst you still have your build.gradle file open, you’ll need to change the first line :

apply plugin: ‘com.android.application’

apply plugin: ‘com.android.library’

####6. Remove applicationId

You’ll also need to remove applicationId in defaultConfig before synchronising again.

Источник

Add build dependencies

The Gradle build system in Android Studio makes it easy to include external binaries or other library modules to your build as dependencies. The dependencies can be located on your machine or in a remote repository, and any transitive dependencies they declare are automatically included as well. This page describes how to use dependencies with your Android project, including details about behaviors and configurations that are specific to the Android plugin for Gradle. For a deeper conceptual guide to Gradle dependencies, you should also see the Gradle guide for dependency management —but remember that your Android project must use only the dependency configurations defined on this page.

Dependency types

To add a dependency to your project, specify a dependency configuration such as implementation in the dependencies block of your build.gradle file.

For example, the following build.gradle file for an app module includes three different types of dependencies:

Groovy

Kotlin

Each of these requests a different kind of library dependency as follows:

Local library module dependency

Groovy

Kotlin

This declares a dependency on an Android library module named «mylibrary» (this name must match the library name defined with an include: in your settings.gradle file). When you build your app, the build system compiles the library module and packages the resulting compiled contents in the app.

Local binary dependency

Groovy

Kotlin

Gradle declares dependencies on JAR files inside your project’s module_name /libs/ directory (because Gradle reads paths relative to the build.gradle file).

Alternatively, you can specify individual files as follows:

Groovy

Kotlin

Groovy

Kotlin

This is actually shorthand for the following:

Groovy

Kotlin

This declares a dependency on version 12.3 of the «app-magic» library, inside the «com.example.android» namespace group.

Note: Remote dependencies like this require that you declare the appropriate remote repositories where Gradle should look for the library. If the library does not already exist locally, Gradle pulls it from the remote site when the build requires it (such as when you click Sync Project with Gradle Files or when you run a build).

Native dependencies

As of Android Gradle plugin 4.0, native dependencies can also be imported in the manner described in this document.

Depending on an AAR that exposes native libraries will automatically make them available to the build system used by externalNativeBuild . To access the libraries from your code, you must link to them in your native build scripts. In this document, see Using native dependencies.

Dependency configurations

Inside the dependencies block, you can declare a library dependency using one of several different dependency configurations (such as implementation shown above). Each dependency configuration provides Gradle with different instructions about how to use the dependency. The following table describes each of the configurations you can use for a dependency in your Android project. The table also compares these configurations to those that were deprecated as of Android Gradle plugin 3.0.0.

To add a dependency on a library that is an annotation processor, you must add it to the annotation processor classpath using the annotationProcessor configuration. That’s because using this configuration improves build performance by separating the compile classpath from the annotation processor classpath. If Gradle finds annotation processors on the compile classpath, it deactivates compile avoidance, which negatively impacts build time (Gradle 5.0 and higher ignore annotation processors found on the compile classpath).

The Android Gradle plugin assumes a dependency is an annotation processor if its JAR file contains the following file:

If the plugin detects an annotation processor that’s on the compile classpath, it produces a build error.

Note: Kotlin projects should use kapt to declare annotation processor dependencies.

Use this configuration to include lint checks you want Gradle to execute when building your project.

Note: When using Android Gradle plugin 3.4.0 and higher, this dependency configuration no longer packages the lint checks in your Android Library projects. To include lint check dependencies in your AAR libraries, use the lintPublish configuration described below.

Configuration Behavior
implementation Gradle adds the dependency to the compile classpath and packages the dependency to the build output. However, when your module configures an implementation dependency, it’s letting Gradle know that you do not want the module to leak the dependency to other modules at compile time. That is, the dependency is available to other modules only at runtime.

Using this dependency configuration instead of api or compile (deprecated) can result in significant build time improvements because it reduces the number of modules that the build system needs to recompile. For example, if an implementation dependency changes its API, Gradle recompiles only that dependency and the modules that directly depend on it. Most app and test modules should use this configuration.

api Gradle adds the dependency to the compile classpath and build output. When a module includes an api dependency, it’s letting Gradle know that the module wants to transitively export that dependency to other modules, so that it’s available to them at both runtime and compile time.

This configuration behaves just like compile (which is now deprecated), but you should use it with caution and only with dependencies that you need to transitively export to other upstream consumers. That’s because, if an api dependency changes its external API, Gradle recompiles all modules that have access to that dependency at compile time. So, having a large number of api dependencies can significantly increase build time. Unless you want to expose a dependency’s API to a separate module, library modules should instead use implementation dependencies.

compileOnly Gradle adds the dependency to the compile classpath only (that is, it is not added to the build output). This is useful when you’re creating an Android module and you need the dependency during compilation, but it’s optional to have it present at runtime.

If you use this configuration, then your library module must include a runtime condition to check whether the dependency is available, and then gracefully change its behavior so it can still function if it’s not provided. This helps reduce the size of the final app by not adding transient dependencies that aren’t critical. This configuration behaves just like provided (which is now deprecated).

Note: You can’t use the compileOnly configuration with AAR dependencies.

runtimeOnly Gradle adds the dependency to the build output only, for use during runtime. That is, it is not added to the compile classpath. This configuration behaves just like apk (which is now deprecated).
annotationProcessor
lintPublish Use this configuration in Android library projects to include lint checks you want Gradle to compile into a lint.jar file and package in your AAR. This causes projects that consume your AAR to also apply those lint checks. If you were previously using the lintChecks dependency configuration to include lint checks in the published AAR, you need to migrate those dependencies to instead use the lintPublish configuration.

Groovy

Kotlin

Deprecated Gradle configurations (available in AGP 1.0–4.2)

Configuration Behavior
apk Gradle adds the dependency to the build output only, for use during runtime. That is, it is not added to the compile classpath.
compile Gradle adds the dependency to the compile classpath and build output. Exports the dependency to other modules.
provided Gradle adds the dependency to the compile classpath only (that is, it is not added to the build output).

All of the above configurations apply dependencies to all build variants. If you instead want to declare a dependency for only a specific build variant source set or for a testing source set, you must capitalize the configuration name and prefix it with the name of the build variant or testing source set.

For example, to add an implementation dependency only to your «free» product flavor (using a remote binary dependency), it looks like this:

Groovy

Kotlin

However, if you want to add a dependency for a variant that combines a product flavor and a build type, then you must initialize the configuration name in the configurations block. The following sample adds a runtimeOnly dependency to your «freeDebug» build variant (using a local binary dependency).

Groovy

Kotlin

To add implementation dependencies for your local tests and instrumented tests , it looks like this:

Groovy

Kotlin

However, certain configurations don’t make sense in this situation. For example, because other modules can’t depend on androidTest , you get the following warning if you use the androidTestApi configuration:

Add annotation processors

If you add annotation processors to your compile classpath, you’ll see an error message similar to the following:

To resolve this error, add annotation processors to your project by configuring your dependency using annotationProcessor as shown below:

Groovy

Kotlin

Note: Android plugin for Gradle 3.0.0+ no longer supports android-apt plugin.

Pass arguments to annotation processors

If you need to pass arguments to an annotation processor, you can do so using the AnnotationProcessorOptions block in your module’s build configuration. For example, if you want to pass primitive data types as key-value pairs, you can use the argument property, as shown below:

Groovy

Kotlin

However, when using Android Gradle plugin 3.2.0 and higher, you need to pass processor arguments that represent files or directories using Gradle’s CommandLineArgumentProvider interface.

Using CommandLineArgumentProvider allows you or the annotation processor author to improve the correctness and performance of incremental and cached clean builds by applying incremental build property type annotations to each argument.

For example, the class below implements CommandLineArgumentProvider and annotates each argument for the processor. The sample also uses the Groovy language syntax and is included directly in the module’s build.gradle file.

Groovy

Kotlin

After you define a class that implements CommandLineArgumentProvider , you need to create an instance and pass it to the Android plugin using the annotationProcessorOptions.compilerArgumentProvider method, as shown below.

Groovy

Kotlin

To learn more about how implementing CommandLineArgumentProvider helps improve build performance, read Caching Java projects.

Disable the annotation processor error check

If you have dependencies on the compile classpath that include annotation processors you don’t need, you can disable the error check by adding the following to your build.gradle file. Keep in mind, the annotation processors you add to the compile classpath are still not added to the processor classpath.

Groovy

Kotlin

If you use Kotlin and kapt:

Groovy

Kotlin

If you experience issues after migrating your project’s annotation processors to the processor classpath, you can allow annotation processors on the compile classpath by setting includeCompileClasspath to true . However, setting this property to true is not recommended, and the option to do so will be removed in a future update of the Android plugin.

Exclude transitive dependencies

As an app grows in scope, it can contain a number of dependencies including direct dependencies and transitive dependencies (libraries which your app’s imported libraries depend on). To exclude transitive dependencies that you no longer need, you can use the exclude keyword as given below:

Groovy

Kotlin

Exclude transitive dependencies from test configurations

If you need to exclude certain transitive dependencies from your tests, the code sample shown above might not work as expected. That’s because a test configuration (e.g., androidTestImplementation ) extends the module’s implementation configuration. That is, it always contains implementation dependencies when Gradle resolves the configuration.

So, to exclude transitive dependencies from your tests, you must do so at execution time as shown below:

Groovy

Kotlin

Note: You can still use the exclude keyword in the dependencies block as shown in the original code sample from the Exclude transitive dependencies section to omit transitive dependencies that are specific to the test configuration and are not included in other configurations.

Configure Wear OS app dependencies

Configuring dependencies for a Wear OS module is similar to that of any other module; that is, Wear OS modules use the same dependency configurations, such as implementation and compileOnly .

Wear modules also support variant-aware dependency management. As a result, if your base app module has a dependency on a Wear module, each variant of the base module consumes the matching variant from the Wear module. If you are building a simple app with a dependency on only one Wear module, where the module configures the same variants as your base module, you need to specify the wearApp configuration in your base module’s build.gradle file as shown below:

Groovy

Kotlin

If you have multiple Wear modules and you want to specify a different Wear module per app flavor, you can do so using the flavor WearApp configuration, as follows (however, you can’t include other dependencies that use the wearApp configuration):

Groovy

Kotlin

Remote repositories

When your dependency is something other than a local library or file tree, Gradle looks for the files in whichever online repositories are specified in the repositories block of your build.gradle file. The order in which you list each repository determines the order in which Gradle searches the repositories for each project dependency. For example, if a dependency is available from both repository A and B, and you list A first, Gradle downloads the dependency from repository A.

By default, new Android Studio projects specifies Google’s Maven repository and JCenter as repository locations in the project’s top-level build.gradle file, as shown below:

Groovy

Kotlin

If you want something from the Maven central repository, then add mavenCentral() , or for a local repository use mavenLocal() :

Groovy

Kotlin

Or you can declare specific Maven or Ivy repositories as follows:

Groovy

Kotlin

For more information, see the Gradle Repositories guide.

Google’s Maven repository

The most recent versions of the following Android libraries are available from Google’s Maven repository:

You can see all available artifacts at Google’s Maven repository index (see below for programmatic access).

To add one of these libraries to your build, include Google’s Maven repository in your top-level build.gradle file:

Groovy

Kotlin

Then add the desired library to your module’s dependencies block. For example,the appcompat library looks like this:

Groovy

Kotlin

However, if you’re trying to use an older version of the above libraries and your dependency fails, then it’s not available in the Maven repository and you must instead get the library from the offline repository.

Programmatic access

For programmatic access to Google’s Maven artifacts, you can get an XML list of artifact groups from maven.google.com/master-index.xml. Then, for any group, you can view its library names and versions at:

maven.google.com/ group_path /group-index.xml

For example, libraries in the android.arch.lifecycle group are listed at maven.google.com/android/arch/lifecycle/group-index.xml.

You can also download the POM and JAR files at:

maven.google.com/ group_path / library / version / library — version . ext

Offline repository from SDK Manager

For libraries not available from the Google Maven repository (usually older library versions), you must download the offline Google Repository package from the SDK Manager.

Then you can add these libraries to your dependencies block as usual.

The offline libraries are saved in android_sdk /extras/ .

Native dependencies with the Android Gradle plugin

AAR libraries can contain native dependencies that the Android Gradle Plugin can consume. AGP is also capable of producing AARs that expose native libraries to their consumers.

Using native dependencies

Starting with Android Gradle plugin 4.0, C/C++ dependencies can be imported from AARs linked in your build.gradle file. Gradle will automatically make these available to the native build system, but your build system must be configured to make use of the imported libraries and headers. Since C/C++ dependencies are distributed as AARs, the following links about generic AARs may be helpful:

  • Creating an Android Library for generic AAR documentation and how to integrate it into your project, especially when you want to use the AAR as a local C/C++ dependency.
  • Add build dependencies for information on adding dependencies to your build.gradle file, especially for the remote dependencies.

This document focuses on how to configure your native build system and assumes you’ve already added a C/C++ dependency AAR into your project’s Gradle build environment.

Native dependencies in AARs

AAR dependencies of your Gradle modules can expose native libraries for use by your application. Inside the AAR, the prefab directory contains a Prefab package, which includes the headers and libraries of the native dependency.

Each dependency can expose at most one Prefab package, which comprises one or more modules. A Prefab module is a single library, which could be either a shared, static, or header only library.

The package and module names need to be known to make use of the libraries. By convention the package name will match the Maven artifact name and the module name will match the C/C++ library name, but this is not required. Consult the dependency’s documentation to determine what names it uses.

Build system configuration

Android Gradle Plugin 4.0 Android Gradle Plugin 4.1+

The prefab feature must be enabled for your Android Gradle module.

To do so, add the following to the android block of your module’s build.gradle file:

Groovy

Kotlin

Dependencies imported from an AAR are exposed to CMake via CMAKE_FIND_ROOT_PATH. This value will be set automatically by Gradle when CMake is invoked, so if your build modifies this variable be sure to append rather than assign to it.

Each dependency exposes a config-file package to your build. These are imported with the find_package command. This command searches for config-file packages matching the given package name and version and exposes the targets it defines to be used in your build. For example, if your application defines libapp.so and it uses cURL, your CMakeLists.txt should include the following:

app.cpp is now able to #include «curl/curl.h» , libapp.so will be automatically linked against libcurl.so when building, and libcurl.so will be included with the app.

Publishing native libraries in AARs

The ability to create native AARs was first added in AGP 4.1.

To export your native libraries, add the following to the android block of your library project’s build.gradle file:

Groovy

Kotlin

In this example, the mylibrary and myotherlibrary libraries from either your ndk-build or CMake external native build will be packaged in the AAR produced by your build, and each will export the headers from the specified directory to their dependents.

Dependency order

The order in which you list your dependencies indicates the priority for each: the first library is higher priority than the second, the second is higher priority than the third, and so on. This order is important in the event that resources are merged or manifest elements are merged into your app from the libraries.

For example, if your project declares the following:

  • Dependency on LIB_A and LIB_B (in that order)
  • And LIB_A depends on LIB_C and LIB_D (in that order)
  • And LIB_B also depends on LIB_C

Then, the flat dependency order will be as follows:

This ensures that both LIB_A and LIB_B can override LIB_C ; and LIB_D is still higher priority than LIB_B because LIB_A (which depends on it) has higher priority than LIB_B .

For more information about how manifests from different project sources/dependencies are merged, see Merge multiple manifest files.

View module dependencies

Some direct dependencies may have dependencies of their own. These are called transitive dependencies. Rather than requiring you to manually declare each transitive dependency, Gradle automatically gathers and adds them for you. The Android plugin for Gradle provides a task that displays a list of the dependencies Gradle resolves for a given module.

For each module, the report also groups the dependencies based on build variant, testing source set, and classpath. The following is sample report for an app module’s runtime classpath of its debug build variant and compile classpath of its instrumented test source set.

To run the task, proceed as follows:

  1. Select View > Tool Windows > Gradle (or click Gradle in the tool windows bar).
  2. Expand AppName > Tasks > android and double-click androidDependencies. After Gradle executes the task, the Run window should open to display the output.

For more information about managing dependencies in Gradle, see Dependency management basics in the Gradle User Guide.

Fix dependency resolution errors

When you add multiple dependencies to your app project, those direct and transitive dependencies might conflict with one another. The Android Gradle plugin tries to resolve these conflicts gracefully, but some conflicts may lead to compile time or runtime errors.

To help you investigate which dependencies are contributing to errors, inspect your app’s dependency tree and look for dependencies that appear more than once or with conflicting versions.

If you can’t easily identify the duplicate dependency, try using Android Studio’s UI to search for dependencies that include the duplicate class as follows:

  1. Select Navigate > Class from the menu bar.
  2. In the pop-up search dialog, make sure that the box next to Include non-project items is checked.
  3. Type the name of the class that appears in the build error.
  4. Inspect the results for the dependencies that include the class.

The following sections describe the different types of dependency resolution errors you may encounter and how to fix them.

Fix duplicate class errors

If a class appears more than once on the runtime classpath, you get an error similar to the following:

This error typically occurs due to one of the following circumstances:

  • A binary dependency includes a library that your app also includes as a direct dependency. For example, your app declares a direct dependency on Library A and Library B, but Library A already includes Library B in its binary.
    • To resolve this issue, remove Library B as a direct dependency.
  • Your app has a local binary dependency and a remote binary dependency on the same library.
    • To resolve this issue, remove one of the binary dependencies.

Fix conflicts between classpaths

When Gradle resolves the compile classpath, it first resolves the runtime classpath and uses the result to determine what versions of dependencies should be added to the compile classpath. In other words, the runtime classpath determines the required version numbers for identical dependencies on downstream classpaths.

Your app’s runtime classpath also determines the version numbers that Gradle requires for matching dependencies in the runtime classpath for the app’s test APK. The hierarchy of classpaths is described in figure 1.

Figure 1. Version numbers of dependencies that appear across multiple classpaths must match according to this hierarchy.

A conflict where different versions of the same dependency appears across multiple classpaths might occur when, for example, your app includes a version of a dependency using the implementation dependency configuration and a library module includes a different version of the dependency using the runtimeOnly configuration.

When resolving dependencies on your runtime and compile time classpaths, Android Gradle plugin 3.3.0 and higher attempt to automatically fix certain downstream version conflicts. For example, if the runtime classpath includes Library A version 2.0 and the compile classpath includes Library A version 1.0, the plugin automatically updates the dependency on the compile classpath to Library A version 2.0 to avoid errors.

However, if the runtime classpath includes Library A version 1.0 and the compile classpath includes Library A version 2.0, the plugin does not downgrade the dependency on the compile classpath to Library A version 1.0, and you still get an error similar to the following:

To resolve this issue, do one of the following:

  • Include the desired version of the dependency as an api dependency to your library module. That is, only your library module declares the dependency, but the app module will also have access to its API, transitively.
  • Alternatively, you can declare the dependency in both modules, but you should make sure that each module uses the same version of the dependency. Consider configuring project-wide properties to ensure versions of each dependency remain consistent throughout your project.

Apply custom build logic

This section describes advanced topics that are useful when you want to extend the Android Gradle plugin or write your own plugin.

Publish variant dependencies to custom logic

A library can have functionalities that other projects or sub-projects might want to use. Publishing a library is the process by which the library is made available to its consumers. Libraries can control which dependencies its consumers have access to at compile time and runtime.

There are two separate configurations that hold the transitive dependencies of each classpath which must be used by consumers to consume the library as described below:

  • variant_name ApiElements : This configuration holds the transitive dependencies that are available to consumers at compile time.
  • variant_name RuntimeElements : This configuration holds the transitive dependencies that are available to consumers at runtime.

To learn more about the relationships between the different configurations, go to The Java Library plugin configurations.

Custom dependency resolution strategies

A project may include a dependency on two different versions of the same library which can lead to dependency conflicts. For example, if your project depends on version 1 of module A and version 2 of module B, and module A transitively depends on version 3 of module B, there arises a dependency version conflict.

To resolve this conflict, the Android Gradle plugin uses the following dependency resolution strategy: when the plugin detects that different versions of the same module are in the dependency graph, by default, it chooses the one with the highest version number.

However, this strategy might not always work as you intend. To customize the dependency resolution strategy, use the following configurations to resolve specific dependencies of a variant that are needed for your task:

  • variant_name CompileClasspath : This configuration contains the resolution strategy for a given variant’s compile classpath.
  • variant_name RuntimeClasspath : This configuration contains the resolution strategy for a given variant’s runtime classpath.

The Android Gradle plugin includes getters that you can use to access the configuration objects of each variant. Thus, you can use the variant API to query the dependency resolution as shown in the example below:

Groovy

Kotlin

Dependency information for Play Console

When building your app using AGP 4.0.0 and higher, the plugin includes metadata that describes the library dependencies that are compiled into your app. When uploading your app, the Play Console inspects this metadata to provide alerts for known issues with SDKs and dependencies your app uses, and, in some cases, provide actionable feedback to resolve those issues.

The data is compressed, encrypted by a Google Play signing key, and stored in the signing block of your release app. We recommend keeping this dependencies file for a safe and positive user experience. However, if you’d rather not share this information, you can opt out by including the following dependenciesInfo block in your module’s build.gradle file:

For more information on our policies and potential issues with dependencies, see our support page on using third-party SDKs in your app.

Content and code samples on this page are subject to the licenses described in the Content License. Java is a registered trademark of Oracle and/or its affiliates.

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