[JAVA_API] Reorganize project structure and automatically load native libraries (openvinotoolkit#668)

* [JAVA_API] Restructure project directories to improve code organization

* Moved java files to src/main/java

* Moved cpp files to src/main/cpp

* Moved tests to src/test/java

* Updated gradle build script, CMake script and sphinx build config

* [JAVA_API] Add gitignore

Added .gitignore

* [JAVA_API] Load native libraries in static initializer blocks

* Add static initializer blocks to automatically load the required native libraries when the class is loaded

* Introduce the NativeLibrary class to encapsulate the logic for finding and loading native libs

* Fix java code style

* Remove unused imports

Remove unused imports to fix java code style

* [JAVA_API] Remove static blocks from subclasses to avoid code duplication

* [JAVA_API] Load native libraries in compatibility classes

* Add static initializer block in compatibility classes to automatically load native libraries when the class is loaded

* [JAVA_API][DOCS] Add instructions for running java tests

* Add documentation for instructions on running Java tests in IntelliJ IDEA

* [JAVA_API][DOCS] Build and IDE instructions

* Add additional build instructions and dev env setup steps using IntelliJ IDEA

* [JAVA_API] Fix Java samples

* Remove explicit native library loads

* Remove duplicate helper methods

* [JAVA_API] Move test README

* [JAVA_API][DOCS] Add instructions for running samples in IDE

* Add instructions to run java benchmark app and face detection samples using IntelliJ IDEA

* Fix typos

* Update Java API test instructions

Co-authored-by: Anna Likholat <aniali201398@gmail.com>

* [JAVA_API] Restructure sample projects 

* Restructure Java sample applications to improve code organization

* Fix OpenCV build/install path resolution for non-linux platforms

* [JAVA_API][DOCS] Instructions for Java and Kotlin samples

* Revert IDE formatting changes

* [DOCS] Fix broken link

* Fix link to test readme

---------

Co-authored-by: Ilya Lavrenov <ilya.lavrenov@intel.com>
Co-authored-by: Anna Likholat <aniali201398@gmail.com>

Author: 3 people

modules/java_api/.gitignore

@@ -0,0 +1,2 @@
+.gradle
+**/build/

modules/java_api/CMakeLists.txt

@@ -18,13 +18,13 @@ if(NOT OpenVINODeveloperPackage_FOUND)
     find_package(OpenVINO REQUIRED)
 endif()
 
-file(GLOB_RECURSE sources ${CMAKE_CURRENT_SOURCE_DIR}/cpp/*.cpp)
+file(GLOB_RECURSE sources ${CMAKE_CURRENT_SOURCE_DIR}/src/main/cpp/*.cpp)
 
 add_library(${PROJECT_NAME} SHARED ${sources})
 
 target_link_libraries(${PROJECT_NAME} PRIVATE openvino::runtime)
 target_include_directories(${PROJECT_NAME} PRIVATE ${JNI_INCLUDE_DIRS})
-target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/cpp)
+target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src/main/cpp)
 
 install(TARGETS ${PROJECT_NAME}
         RUNTIME DESTINATION ${IE_CPACK_RUNTIME_PATH} COMPONENT java_api

modules/java_api/README.md

@@ -9,13 +9,20 @@
 To install OpenJDK:
 
 * Ubuntu systems:
-```bash
-sudo apt-get install -y default-jdk
-```
+    ```bash
+    sudo apt-get install -y default-jdk
+    ```
 
-### Build
+## Build
+
+To build OpenVINO so that it includes this module, use the following CMake command:
+```shell
+cd <openvino_build>
+cmake -DBUILD_java_api=ON -DOPENVINO_EXTRA_MODULES=<openvino_contrib>/modules <openvino_source_directory>
+cmake --build . -j8
+```
 
-Set environment OpenVINO variables:
+Set OpenVINO environment variables:
 ```bash
 source <openvino_install>/setupvars.sh
 ```
@@ -26,6 +33,20 @@ cd openvino_contrib/modules/java_api
 gradle build
 ```
 
-### Import
+## Import
 
 Use `import org.intel.openvino.*;` for OpenVINO Java API 2.0 or `import org.intel.openvino.compatibility.*;` for deprecated API.
+
+## Set up the development environment
+
+### Import to IntelliJ IDEA
+
+- Install and enable the **Gradle** IntelliJ Plugin by navigating to **Settings** > **Plugins**. Search for the
+  Gradle plugin and install it, if not already installed.
+- Clone the repository
+  ```shell
+  git clone https://github.com/openvinotoolkit/openvino_contrib.git
+  ```
+- To import the project into IntelliJ IDEA, select **File** > **Open** and locate the  java api module in `<openvino_contrib>/modules/java_api`.
+
+See [here](src/test/README.md) for instructions on running tests.

modules/java_api/build.gradle

@@ -3,6 +3,7 @@ plugins {
 }
 
 import org.gradle.internal.os.OperatingSystem
+
 println 'Operating system: ' + OperatingSystem.current()
 def arch = System.getProperty("os.arch")
 def ov_arch = arch;
@@ -60,26 +61,26 @@ native_resources.each {
         }
     }
 }
-file('native').mkdirs()
-file('native/resources_list.txt').text = "${resources_list}"
+file('src/main/native').mkdirs()
+file('src/main/native/resources_list.txt').text = "${resources_list}"
 sourceSets {
     main {
         java {
-            srcDirs = ["org"]
+            srcDirs = ["src/main/java"]
         }
         resources {
             srcDirs = native_resources
-            srcDir 'native'
+            srcDir 'src/main/native'
         }
     }
     test {
         java {
-            srcDirs = ["."]
-            include "tests/compatibility/*.java", "tests/*.java"
+            srcDirs = ["src/test/java"]
+            include "org/intel/openvino/compatibility/*.java", "org/intel/openvino/*.java"
         }
     }
 }
-repositories{
+repositories {
     mavenCentral()
 }
 dependencies {
@@ -90,4 +91,4 @@ test {
     systemProperty 'MODELS_PATH', System.getProperty('MODELS_PATH')
     systemProperty 'device', System.getProperty('device')
 }
-test.onlyIf { project.hasProperty('run_tests') }
+test.onlyIf { project.hasProperty('run_tests') }

modules/java_api/docs/conf.py

@@ -53,6 +53,6 @@
 html_title = 'OpenVINO for Java'
 
 import subprocess # nosec
-subprocess.call('javadoc ../org/intel/openvino/*.java', shell=True)
+subprocess.call('javadoc ../src/main/java/org/intel/openvino/*.java', shell=True)
 
 html_extra_path = ['.']