I upgraded jdk to version 7_45. After compiling and executing the jar, which works fine, i packed it into an application bundle. But unfortunately i get this error message \
I kinda solved the problem. I took a look at a Processing app bundle. I think it mainly has to do with following lines in the info.plist which were missing in mine:
JVMOptions
-Xdock:icon=Contents/Resources/fireworks.icns
-Dapple.laf.useScreenMenuBar=true
-Dcom.apple.macos.use-file-dialog-packages=true
-Dcom.apple.macos.useScreenMenuBar=true
-Dcom.apple.mrj.application.apple.menu.about.name=Main
-Dcom.apple.smallTabs=true