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Author: kirklandsign

extension/android/README.md

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+# 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:
+```sh
+export ANDROID_HOME=/path/to/sdk
+export ANDROID_NDK=/path/to/ndk
+sh scripts/build_android_library.sh
+```
+
+Please see [Android building from source](https://pytorch.org/executorch/main/using-executorch-android.html#building-from-source) for details
+
+## Test
+
+After the library is built,
+
+```sh
+# Run unit test
+./gradlew :executorch_android:testDebugUnitTest
+
+# Run instrumentation test
+./gradlew :executorch_android:connectedAndroidTest
+```