Introduction

This project is a tool for creating a Windows executable that launches a Java application which is bundled with a JRE.

The generated exe-file is around 30 kb if compiled with Mingw-w64 toolchain, and 110 kb if compiled with MSVC, and will normally not need to be updated unless you rename your main Java class or change the application icon. That means that the most convenient probably is to add the compiled exe-file to your project's Git repository and just include in the package when generating a release-bundle, but you can of course also add the compilation step as a part of the build process.

The file structure of the deployed Java application would typically look something like this

my_project/
    myapp.exe        # the launcher created by this project
    jre/             # the bundled JRE
    lib/
        my_app.jar    # your Java application
        ...           # any third-party libraries, etc.

When the user launches myapp.exe, it will launch your Java application with the bundled JRE, with a command that looks like jre\bin\java.exe --class-path "lib/*" com.example.MyApplication. You can configure the command line in launcher.cpp, as described below.

Usage instructions

Locate the line starting with #define ARGS at the top of launcher.cpp. Replace com.example.MyApplication with the name of your main Java class (the class that has the main method). Make any other configurations you need, for example by adding directories to the classpath, or by adding additional arguments to the call to java.exe.

You can also configure the JAVAPATH define if your JRE is in a different directory than jre/.

You can replace icon.ico with your own icon, or if you don't want to use an icon, just remove the things related to resources.res from the commands below.

Compile the executable:

• On Windows, using Mingw-w64

  Install MSYS2 tools from https://www.msys2.org/, open the MinGW 64-bit terminal and run

  g++ -o launcher.o -c launcher.cpp
  windres resources.rc --output-format=coff --output=resources.res
  g++ -o launcher.exe -static -s -mwindows launcher.o resources.res -lshlwapi
  

• On Windows, using MSVC command line tools

  Open the Developer Command Prompt for Visual Studio and run:

  CL /O1 /EHsc -c launcher.cpp
  RC /fo resources.res resources.rc
  LINK /OUT:launcher.exe /SUBSYSTEM:WINDOWS /ENTRY:"mainCRTStartup" launcher.obj resources.res user32.lib shlwapi.lib
  

• On Linux, using Mingw-w64 toolchain

  It is possible to cross-compile the Windows executable from Linux, using the x86_64-w64-mingw32 toolchain. On Ubuntu, the toolchain can be installed with sudo apt install g++-mingw-w64-x86-64.

  x86_64-w64-mingw32-g++ -o launcher.o -c launcher.cpp
  x86_64-w64-mingw32-windres resources.rc --output-format=coff --output=resources.res
  x86_64-w64-mingw32-g++ -o launcher.exe -static -s -mwindows launcher.o resources.res -lshlwapi
  

You will now have a file called launcher.exe, which you can rename to suit your own project.

Example application

You can find an example of how a deployed application might look like under releases