android

ExecuTorch Android

This directory contains the Android Java/Kotlin binding. The final product is an AAR, which contains the .so libraries for c++ runtime, and .jar for Java API, and required metadata AndroidManifest.xml.

Core contents

Under extension/android/,

• executorch_android/ is the root for the Java org.pytorch.executorch package
  • src/
    • androidTest/ contains the android instrumentation test source
    • main/ contains the Java source
    • test/ contains the Java unit test source
  • build.gradle is the rule to build the Java package.
• jni/ contains the JNI layer code, which depends on the ExecuTorch c++ runtime library.
• CMakeLists.txt is the rule for building the JNI library.

Build

scripts/build_android_library.sh is a helper script to build the Java library (into .jar), native library (into .so), and the packaged AAR file.

The usage is:

export ANDROID_HOME=/path/to/sdk
export ANDROID_NDK=/path/to/ndk
sh scripts/build_android_library.sh

The AAR file will be extension/android/executorch_android/build/outputs/aar/executorch_android-debug.aar. If you set an environment variable BUILD_AAR_DIR, then the AAR will be copied to $BUILD_AAR_DIR/executorch.aar. Later, you can copy $BUILD_AAR_DIR/executorch.aar to your app directory to use as a library.

Please see Android building from source for details

Test

After the library is built,

# Set up models for testing
sh executorch_android/android_test_setup.sh

# Run unit test
./gradlew :executorch_android:testDebugUnitTest

# Run instrumentation test
./gradlew :executorch_android:connectedAndroidTest