This is an example code to pass information between Java and C++ program using Protobuf.

Java code calls C++ using JNI(Java Native Interface).

Program gives you 3 options to read and read/write protos.

1. Pass file name to C++ and read proto using C++.
2. Read file in Java and then pass byte array to C++. Convert byte array into proto in C++.
3. Read file in Java and then pass byte array to C++. Add extra elements to proto in C++ and return byte array in Java. Then read byte array in Java.

This example only has been tested on Linux environment. As native C++ code depends on the platform it runs on, you need to modify your build process and java code(native library name in java) to make it work on the platform.

This example leverages Protobuf to transfer data from Java to native code. Here's a link that provides instructions to install protobuf: Click here

I am using Makefile to build files in order. I am using CLASSPATH2 to keep the location of protobuf jar file.

I am using Makefile to perform build activities. Run following command to build your classes.

make all

1. Build protobuf file to generate java class based on proto definition.

2. Build Java file that generates a header file for C++ code.

3. Build C++ file that will be run using JNI by Java code.