The java source code in Simple.java can be compiled just with:

 javac Simple.java

C++ header and sources could be generated with:

java -jar ../../target/java4cpp-1.0-SNAPSHOT-jar-with-dependencies.jar -c Simple 

The generated files include:

• simple.h -- C++ header to be included by users.
• simple0.h -- C++ header included by generated source. Users should not directly include this.
• simple_fwd.h -- C++ header file with forward definitions only. Can be included in other C++ header files where only partial type definitions with minimal dependancy are needed.
• simple0.cpp -- C++ generated source that makes direct JNI calls that should be compiled and linked in to the application possibly in a separate library.

The file use_simple_java.cpp contains the C++ example source code using the generated files with a main method.

Using any C++ IDE or build environment add the JDK include directory and its operating system specific subdirectory to the list of directories searched for header files, the JDK's lib directory to the directories where libraries are searched. Add the jvm library to the link options. Ensure that the class file is on the CLASSPATH and the dynamic jvm library on the list of directories searched for dynamic libraries.

The following instructions were tested on an x64 Windows 7 computer with Visual Studio 2010 and JDK 1.8.0_60 for Windows(x64). Please adjust paths and settings locations as appropriate to match your system. All settings are merely suggested. Once you have a working setup feel free to experiment with the alternatives.

The Simple sudirectory contains the Visual Studio solutions and projects generated.

• Close Visual Studio if it is open so it will get the next environment setting change.

• Add the location of jvm.dll which comes with Java JDK to the Windows Path.

  • In Control Panel, use the text field on the upper right to search for Environment.
  • Under System , click "Edit Environment Variables For Your Account"
    • Select the item for PATH. Add the location of jvm.dll (eg "C:\Program Files\Java\jre1.8.0_60\bin\server;")
    • Click OK in that dialog and then in the parent dialog.

• (Re) Open Visual Studio

  • Select File -> New Project.
  • Under Templates select Visual C++, and Win32 Console Application.
  • Click Next.
  • Under Application Settings select Console Application.
    • Check Empty Project.
    • Uncheck Precompiled Headers
    • Uncheck Security Development Lifecycle(SDL) checks
    • Uncheck ATL (if checked)
    • Uncheck MFC (if checked)
  • Select Source Files and Add Existing Item to add simple0.cpp and use_simple_java.cpp.
  • Select Header Files and Add Existing Items to add simple.h, simple0.h and simple_fwd.h.
  • If you are running on an x64 system and have the x64 version of the JDK installed:
    • Goto Build -> Configuration Manager
    • Under Active Solution Platforms choose New.
    • Under Type or select new platform choose x64.
    • Leave Copy Settings From: Win32 Selected and leave create new project platform checkbox selected, click OK.
  • Under Project -> Properties -> Configuration Properties -> VC++ Directories
    • Add the JDK's include subdirectory and the win32 subdirectory of that to the Include Directories:
      • (eg. C:\Program Files\Java\jdk1.8.0_60\include;C:\Program Files\Java\jdk1.8.0_60\include\win32;$(IncludePath) )
    • Add the JDK's lib subdirectory to Library Directories:
      • (eg. C:\Program Files\Java\jdk1.8.0_60\lib;$(LibraryPath) )
    • Click Apply
  • Under Project -> Properties -> Linker -> Input
    • Add jvm.lib to Additional Dependancies.
    • Click Apply
  • Use Build -> Build Solution to build the application.
  • Use Debug -> Start without Debugging.
    • Output window should print s.getValue() = 4.
    • The C++ application has successfully run passing an argument to a Java class method and recieving a return value from a Java class.

On a system where the JDK was installed in:

/usr/local/jdk1.8.0_60/

The program can be compiled with:

export JAVA_HOME=/usr/local/jdk1.8.0_60/;
g++ -I ${JAVA_HOME}/include -I ${JAVA_HOME}/include/linux -L ${JAVA_HOME}/jre/lib/amd64/server/  -Wl,--rpath ${JAVA_HOME}/jre/lib/amd64/server/  use_simple_java.cpp simple0.cpp -ljvm -o simple

Then run with:

./simple

This produces the output:

s.getValue() = 4

The C++ application has successfully run passing an argument to a Java class method and recieving a return value from a Java class.