Jar Launcher.app : where is it supposed to be located at? On Sierra I installed Java (JDK) and Parallels Desktop. The Windows VM I have in Parallels has decided to set its own (Windows) copy of Java as default for Mac .jar files, which means that whenever I want to run a .jar file by double clicking it runs it in the Windows VM. 

So I opened the menu to change default program to run the file and it showed me a Finder-like window where I would have to pick an App. I wish to set Java Launcher as default, though I don't know where it's locatee.
Yes, it is located at /System/Library/CoreServices/Jar Launcher.app.