flutter-android-sdk-maven-repo

Maven Repository

This directory contains a Maven repository with prebuilt Flutter AAR (Android Archive) artifacts. These artifacts are generated from the Flutter SDK module and can be used by Android applications without requiring the Flutter toolchain.

🌐 Hosted on GitHub Pages: https://iamnabink.github.io/flutter-android-sdk-maven-repo

Overview

The maven-repo/ directory contains compiled Flutter modules packaged as AAR files, organized in standard Maven repository structure. This repository is hosted on GitHub Pages, making it accessible to any Android project via a simple URL.

What is Maven Repository Hosting?

Maven repository hosting is a method of distributing Android libraries (AAR files) in a standardized format that Gradle and other build tools can automatically resolve. This example project demonstrates:

  1. Local Maven Repository: A file-system based repository structure that follows Maven conventions
  2. GitHub Pages Hosting: How to serve the repository over HTTP using GitHub Pages
  3. AAR Distribution: Packaging Flutter modules as AAR files for easy Android integration

Why Use Maven Repository for AAR Files?

How It Works

When you build a Flutter module with flutter build aar, Flutter generates:

These files are organized in a Maven repository structure:

maven-repo/
└── <groupId>/<artifactId>/<version>/
    ├── <artifactId>-<version>.aar
    └── <artifactId>-<version>.pom

Gradle can then resolve these dependencies automatically when you add the repository URL and dependency declaration.

maven-repo/
└── dev/
    └── nabrajkhadka/
        └── example/
            └── flutter_module/
                ├── flutter_debug/1.0/
                ├── flutter_release/1.0/
                └── flutter_profile/1.0/

Contents

This repository contains the following artifacts:

Flutter Module Artifacts

Each artifact includes:

Usage in Android Projects

Step 1: Add Repository

Add the Maven repository to your app/build.gradle or root build.gradle:

Option 1: Use GitHub Pages (Recommended)

repositories {
    maven {
        // GitHub Pages hosted Maven repository
        url 'https://iamnabink.github.io/flutter-android-sdk-maven-repo'
    }
    
    // Required: Flutter's Android embedding dependencies
    maven {
        url 'https://storage.googleapis.com/download.flutter.io'
    }
    
    google()
    mavenCentral()
}

Option 2: Use Local Repository

If you prefer to use a local copy of the repository:

repositories {
    maven {
        // Local maven repository containing Flutter AAR artifacts
        url '../maven-repo'  // Adjust path relative to your project
        // Or use absolute path:
        // url file('path/to/maven-repo')
    }
    
    // Required: Flutter's Android embedding dependencies
    maven {
        url 'https://storage.googleapis.com/download.flutter.io'
    }
    
    google()
    mavenCentral()
}

Step 2: Add Dependencies

Add the Flutter module dependencies to your app/build.gradle:

dependencies {
    // Release build variant
    releaseImplementation ('dev.nabrajkhadka.example.flutter_module:flutter_release:1.0@aar') {
        transitive = true
    }
    
    // Debug build variant
    debugImplementation ('dev.nabrajkhadka.example.flutter_module:flutter_debug:1.0@aar') {
        transitive = true
    }
    
    // Profile build variant (optional)
    profileImplementation ('dev.nabrajkhadka.example.flutter_module:flutter_profile:1.0@aar') {
        transitive = true
    }
    
    // Required: MultiDex support
    implementation 'androidx.multidex:multidex:2.0.1'
}

Important Notes:

Step 3: Configure AndroidManifest.xml

Add Flutter embedding metadata inside the <application> tag:

<meta-data
    android:name="flutterEmbedding"
    android:value="2" />

Repository Structure

The Maven repository follows the standard Maven directory layout:

maven-repo/
└── <groupId>/
    └── <artifactId>/
        └── <version>/
            ├── <artifactId>-<version>.aar
            └── <artifactId>-<version>.pom

Where:

Troubleshooting

“Could not find flutter_embedding”

“Could not resolve dependency”

“minSdkVersion mismatch”

Building and Publishing AAR Files

Step 1: Build Flutter AAR

From the flutter_sdk/ directory, build the AAR files:

cd flutter_sdk
flutter pub get
flutter build aar

This generates AAR files in build/host/outputs/repo/ with the standard Maven structure.

Step 2: Copy to Maven Repository

Copy the generated repository contents to maven-repo/:

# From project root
cp -r flutter_sdk/build/host/outputs/repo/* maven-repo/

Or manually copy the directory structure:

Step 3: Verify Repository Structure

Ensure the repository follows Maven conventions:

maven-repo/
└── dev/
    └── nabrajkhadka/
        └── example/
            └── flutter_module/
                ├── flutter_debug/
                │   └── 1.0/
                │       ├── flutter_debug-1.0.aar
                │       └── flutter_debug-1.0.pom
                ├── flutter_release/
                │   └── 1.0/
                │       ├── flutter_release-1.0.aar
                │       └── flutter_release-1.0.pom
                └── flutter_profile/
                    └── 1.0/
                        ├── flutter_profile-1.0.aar
                        └── flutter_profile-1.0.pom

Publishing to GitHub Pages

This repository is configured to be served via GitHub Pages. To set up GitHub Pages for your repository:

  1. Enable GitHub Pages:
    • Go to your repository settings on GitHub
    • Navigate to “Pages” section
    • Set source to the branch containing maven-repo/ (usually main or master)
    • Set the folder to /maven-repo (or / if maven-repo is in root)
  2. Access the repository:
    • Your Maven repository will be available at: https://<username>.github.io/<repo-name>/maven-repo
    • For this project: https://iamnabink.github.io/flutter-android-sdk-maven-repo
  3. Update artifacts:
    • Build new AAR files using flutter build aar
    • Copy artifacts to maven-repo/ directory
    • Commit and push updates to the maven-repo/ directory
    • GitHub Pages will automatically update (may take a few minutes)

Alternative Hosting Options

While this example uses GitHub Pages, you can host Maven repositories on:

Distribution

This directory is:

For local development, you can also use the local path option in your build.gradle.

Example Project Context

This Maven repository is part of an example Flutter SDK project that demonstrates:

  1. Flutter Module Development: Creating a Flutter module that can be embedded in native apps
  2. AAR Packaging: Building Flutter modules as Android Archive (AAR) files
  3. Maven Repository Setup: Organizing AAR files in a Maven-compatible structure
  4. GitHub Pages Hosting: Serving the Maven repository over HTTP for easy distribution
  5. Android Integration: Consuming the AAR files in Android projects via Gradle

This example serves as a reference implementation for teams looking to:

Best Practices

When hosting AAR files in a Maven repository:

  1. Version Management: Use semantic versioning (e.g., 1.0.0, 1.0.1, 1.1.0)
  2. Build Variants: Maintain separate debug, release, and profile builds
  3. POM Files: Ensure .pom files correctly list all transitive dependencies
  4. Repository Structure: Follow Maven directory conventions strictly
  5. Testing: Test repository access from a clean Android project before distribution
  6. Documentation: Document the Maven coordinates (groupId:artifactId:version) clearly

See Also