Packages your JAR, assets and a JVM for distribution on Windows (ZIP), Linux (ZIP) and Mac OS X (.app), adding a native executable file to make it appear like the app is a native app. Packr is most suitable for GUI applications, such as games made with libGDX

You point packr at your JAR file (containing all your code and assets), a JSON config file (specifying parameters to the JVM and the main class) and a URL or local file location to an OpenJDK build for the platform you want to build. Invoking packr from the command line may look like this:

java -jar packr-1.0-SNAPSHOT-jar-with-dependencies.jar \
     -platform mac \
     -jdk "openjdk-1.7.0-u45-unofficial-icedtea-2.4.3-macosx-x86_64-image.zip" \
     -executable myapp \
     -appjar myapp.jar \
     -mainclass "com/my/app/MainClass"
     -vmargs "-Xmx1G"
     -resources pom.xml;src/main/resources \
     -minimizejre true
     -outdir out

Alternatively, you can put all the command line arguments into a JSON file which might look like this:

my-packaging-config.json

{
    "platform": "mac",
    "jdk": "/Users/badlogic/Downloads/openjdk-1.7.0-u45-unofficial-icedtea-2.4.3-macosx-x86_64-image.zip",
    "executable": "myapp",
    "appjar": "myapp.jar",
    "mainclass": "com/my/app/MainClass",
    "vmargs": [
       "-Xmx1G"
    ],
    "resources": [
        "pom.xml",
        "src/main/resources"
    ],
    "minimizejre": true,
    "outdir": "out-mac"
}

You can then invoke the tool like this:

java -jar packr-1.0-SNAPSHOT-jar-with-dependencies my-packaging-config.json

Finally, you can use packr from within your code. Just add the JAR file to your project, either manually, or via the following Maven dependency:

<dependency>
   <groupId>com.badlogicgames.packr</groupId>
   <artifactId>packr</artifactId>
   <version>1.0</version>
</dependency>

To invoke packr, you need to create an instance of Config and pass it to Packr#pack()

Config config = new Config();
config.platform = Platform.windows;
config.jdk = "/User/badlogic/Downloads/openjdk-for-mac.zip";
config.executable = "myapp";
config.jar = "myjar.jar";
config.mainClass = "com/my/app/MainClass";
config.vmArgs = Arrays.asList("-Xmx1G");
config.minimizeJre = true;
config.outDir = "out-mac";

new Packr().pack(config)

When packing for Windows, the following folder structure will be generated

outdir/
   executable.exe
   yourjar.jar
   config.json
   jre/

Linux (64-bit!)

outdir/
   executable
   yourjar.jar
   config.json
   jre/

Mac OS X

outdir/
   Contents/
      Info.plist
      MacOS/
         executable
         yourjar.jar
         config.json
         jre/
      Resources/

You can futher modify the Info.plist to your liking, e.g. add icons, a bundle identifier etc. If your outdir has the .app extension it will be treated as an application bundle by Mac OS X.

If you only modify the Java code, it's sufficient to invoke Maven

mvn clean package

This will create a packr-VERSION.jar file in target which you can invoke as described in the Usage section above.

If you want to compile the exe files used by packr, install premake, Visual Studio 2010 Express on Windows, Xcode on Mac OS X and GCC on Linux, then invoke the build-xxx scripts in the natives/ folder. Each script will create an executable file for the specific platform and place it under src/main/resources.

• Icons aren't set yet on any platform, need to do that manually.
• Windows is 32-bit only, Linux is 64-bit only, Mac OS X is 64-bit only
• JRE minimization is very conservative, depending on your app, you can carve out stuff from a JRE yourself, disable minimization and pass your custom JRE to packr

Distributing a bundled JVM has security implications, just like bundling any other runtimes like Mono, Air, etc. Make sure you understand the implications before deciding to use this tool. Here's a discussion on the topic.