EasyJNI - Invoking Java code from C++ made easy

Description

This project provides a wrapper for the Java Native Interface (JNI) to provide a more user-friendly interface to interact with Java code from C++. This interface is designed to be closer to the reflection API provided by Java.

Building EasyJNI

EasyJNI requires a JDK to be installed on your computer.

EasyJNI is developed using C++ 17 and CMake 3.23. Installing CMake is required if you want to build from source. To do so, after having installed all the needed tools, you will need to clone the project:

git clone https://github.com/crillab/easyjni.git
cd easyjni
mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=RELEASE
cmake --build .

Using EasyJNI as a library

This library is designed for simplified use in projects using CMake. To use this project, it is possible to create a submodule in your project with the following commands:

git submodule add https://github.com/crillab/easyjni.git libs/easyjni
git submodule update --remote --init --recursive

And then, add the following instructions in your CMakeLists.txt file:

add_subdirectory(libs/easyjni)
add_executable(your_app your_app.h your_app.cpp)
target_link_libraries(your_app libeasyjni)

Example

A built-in example can be found here. This example allows to run any Java program as follows:

./build/easyjni-demo -c a/classpath/entry -c a/file.jar -m my/awesome/MainClass -- arg1 arg2 arg3

The command above runs the main method defined in the Java class my.awesome.MainClass, and passes arg1, arg2 and arg3 as arguments to this program. The classpath for running this program is made of a/classpath/entry and a/file.jar.

Note

The built-in example can only be built on UNIX systems, as it uses getopt() to parse the command line, which is not available on Windows. However, the library itself may be compiled and used on any operating system.