Bundle a Java 7 .jar for Mac

I created a .jar that requires Java 7. I have Java 7 (JDK and JRE) and I can double-click to run the .jar. However, I want to package this into an application.

What I tried: Using Apple's Jar Bundler tool, I successfully created an application; however, when I run it, it quickly appears and disappears in the dock. When I run the internal file JavaApplicationStub from Terminal, I get:

Exception in thread "main" java.lang.UnsupportedClassVersionError: org/lcmmun/kiosk/gui/Kiosk : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at apple.launcher.LaunchRunner.loadMainMethod(LaunchRunner.java:56)
    at apple.launcher.LaunchRunner.run(LaunchRunner.java:112)
    at apple.launcher.LaunchRunner.callMain(LaunchRunner.java:51)
    at apple.launcher.JavaApplicationLauncher.launch(JavaApplicationLauncher.java:52)

which, according to "unsupportedclassversionerror unsupported major.minor version 51.0 unable to load class" means that I don't have Java 7 installed. But I do.

So my hypothesis is that JavaApplicationStub is Java 7-incompatible.

I've also heard of an ANT task to accomplish the same task, but it seemed too complicated, and I don't know how to use ANT. If this really is the solution, though, I'd be happy to learn.

EDIT: I have now also tried Eclipse's Export > Other > Mac OS Application Bundle. This fails as well.

I'm running 10.8 Mountain Lion, 64-bit.

Issue

You are definitely right with your assumption that Apples JavaApplicationStub located here:

System/Library/Frameworks/JavaVM.framework/Resources/MacOS/JavaApplicationStub

is only compatible with Apples own Java Packages build for Mac OS X.

Reason

Apple is discontinuing their own Java System Packages and only supports Java 6 in their fade out process. Oracle took now over and provides Java 7 for Mac OS X from 10.7.3 on. Apple is even discontinuing developer tools like Jar Bundler.app without any notice, as you can see in this post:

Why is Jar Bundler gone in Mac OS X Mountain Lion 10.8.2

Some people even tried desperately to manually increase the JVMVersion property value in Info.plist, read by Apples JavaApplicationStub, from a documented literal 1.6 or 1.6+ to an undocumented literal like 1.7. This won't work either and you will end up with a dialog like this, even if you have installed Oracles Java 7 Package.

So it is likely you will find other inconstancies between the retired Apple Java 6 world and the future Oracle Java 7 world.

Solution

To build an application packages based on Oracles Java 7 you need to use Oracles AppBundler Ant Task containing Oracles JavaAppLauncher. This one now only supports Oracles Java 7 for Mac OS X and isn't backwards compatible with Apples own Java System Packages.

The good news now is, you can inline Oracles Java 7 JRE into your application package. It will be contained within the directory