rust-native · Android Integration

rust-native is a declarative UI framework written in Rust, inspired by React Native. This project demonstrates how to integrate your Rust UI logic into a native Android application using JNI.

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📦 Build the Native Rust Library

Use cargo-ndk to build the shared library (.so) for Android:

cargo ndk -t arm64-v8a -o example-android/app/src/main/jniLibs build --release

This will generate libmain.so inside:

example-android/app/src/main/jniLibs/arm64-v8a/libmain.so

This file is loaded from the Android app via JNI.

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📱 Run on Android Emulator or Device

To build, install, and launch the Android app:

cd example-android

./gradlew assembleDebug
./gradlew installDebug
adb shell monkey -p com.rustnative -c android.intent.category.LAUNCHER 1
adb logcat | grep -A 20 "RUST_NATIVE"

• monkey simulates an app launch
• logcat filters logs from your native Rust code (println! mapped to __android_log_print)

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🔎 Verify Java JNI Integration

Make sure the Java glue code (UiHelper.java) is included in the built APK:

unzip -p example-android/app/build/outputs/apk/debug/app-debug.apk classes.dex | strings | grep -i UiHelper

This checks for the UiHelper class inside the APK.

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📁 Project Structure

example-android/
├── src/
│   └── lib.rs                   # Rust native library code
├── Cargo.toml                   # Rust package manifest

├── app/
│   └── src/main/
│       ├── java/com/rustnative/
│       │   └── UiHelper.java    # Java helper to call Rust code
│       ├── jniLibs/arm64-v8a/
│       │   └── libmain.so       # Compiled Rust library
│       └── AndroidManifest.xml  # Android entry point

├── build.gradle                 # Project-level Gradle config
├── settings.gradle
├── gradlew / gradlew.bat
└── gradle/
    └── wrapper/
        ├── gradle-wrapper.jar
        └── gradle-wrapper.properties

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Built with ❤️ in Rust