Clean up demo app and docs (#2685)

Summary: Pull Request resolved: #2685

Differential Revision: D55357687

Author: kirklandsign

examples/demo-apps/android/ExecuTorchDemo/README.md

@@ -62,15 +62,6 @@ cp deeplab_v3/dlv3_qnn.pte examples/demo-apps/android/ExecuTorchDemo/app/src/mai
 
 We build the required ExecuTorch runtime library to run the model.
 
-#### Java helper classes
-
-Note: This is an ad-hoc solution. We will publish a formal Java package when it is ready. However, for now we need to copy sources from extension/android/src/main/java/org/pytorch/executorch.
-
-```
-mkdir -p examples/demo-apps/android/ExecuTorchDemo/app/src/main/java/com/example/executorchdemo/executor
-cp extension/android/src/main/java/org/pytorch/executorch/*.java examples/demo-apps/android/ExecuTorchDemo/app/src/main/java/com/example/executorchdemo/executor
-```
-
 #### XNNPACK
 
 1. Configure the CMake target for the library with XNNPACK backend:

examples/demo-apps/android/ExecuTorchDemo/app/build.gradle.kts

@@ -57,6 +57,9 @@ dependencies {
   implementation("androidx.constraintlayout:constraintlayout:2.2.0-alpha12")
   implementation("com.facebook.soloader:soloader:0.10.5")
   implementation("com.facebook.fbjni:fbjni:0.5.1")
+  implementation("org.pytorch.executorch:executorch") {
+    exclude("com.facebook.fbjni", "fbjni-java-only")
+  }
   testImplementation("junit:junit:4.13.2")
   androidTestImplementation("androidx.test.ext:junit:1.1.5")
   androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")

examples/demo-apps/android/ExecuTorchDemo/app/src/main/java/com/example/executorchdemo/MainActivity.java

@@ -30,7 +30,6 @@
 import org.pytorch.executorch.EValue;
 import org.pytorch.executorch.Module;
 import org.pytorch.executorch.Tensor;
-import org.pytorch.executorch.TensorImageUtils;
 
 public class MainActivity extends Activity implements Runnable {
   private ImageView mImageView;

extension/android/src/main/java/org/pytorch/executorch/TensorImageUtils.java renamed to examples/demo-apps/android/ExecuTorchDemo/app/src/main/java/com/example/executorchdemo/TensorImageUtils.java

@@ -6,11 +6,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package org.pytorch.executorch;
+package com.example.executorchdemo;
 
 import android.graphics.Bitmap;
 import android.util.Log;
 import java.nio.FloatBuffer;
+import org.pytorch.executorch.Tensor;
 
 /**
  * Contains utility functions for {@link Tensor} creation from {@link android.graphics.Bitmap} or

examples/demo-apps/android/ExecuTorchDemo/settings.gradle.kts

@@ -25,3 +25,5 @@ dependencyResolutionManagement {
 rootProject.name = "ExecuTorch Demo"
 
 include(":app")
+
+includeBuild("../../../../extension/android")

examples/demo-apps/android/ExecuTorchDemo/setup.sh

@@ -8,11 +8,6 @@
 
 set -eu
 
-EXECUTOR_JAVA_DIR=examples/demo-apps/android/ExecuTorchDemo/app/src/main/java/com/example/executorchdemo/executor/
-mkdir -p "${EXECUTOR_JAVA_DIR}"
-# Temporary workaround until we have a formal Java package
-cp extension/android/src/main/java/org/pytorch/executorch/*.java "${EXECUTOR_JAVA_DIR}"
-
 pushd cmake-out
 # Note: Set up ANDROID_NDK, ANDROID_ABI, BUCK2, and FLATC_EXECUTABLE
 cmake .. -DCMAKE_INSTALL_PREFIX=cmake-out \