I am developing a JavaFX 8 application that runs cross-platform on Windows/OSX/Ubuntu via JWrapper. Right now I am using stage.getIcons().add(..) to set the stage icon to a 256x256 PNG bundled with the application. This works on Windows, however on Ubuntu, the dock icon remains the Oracle/Java default icon, as shown below. Is there some third party library, or some technique I can use to get my own icon and tooltip/title to display for the Ubuntu dock icon?
Ubuntu is a bit different: You would need to set the icon within a .desktop file. As far as I recall from our Ant-based build script using the JDKs javapackager tool, it is able to do that for you, but this bundles the whole JRE with it as well and you would need access to a (virtual) machine for each target platform and architecture (there are no Delta packages like in Eclipse, unfortunatly).
So basically when you export your application, you should build a predefined .desktop file, which would specify both the exec command and the path to the icon (whre I don't know, if this needs to be absolute or relative to the .desktop file location).