Linux where to install getdown application files on linux?(using jpackage)

[Magikarp]

As a similar problem faced by another user was left unsolved, I would like to know where to install getdown files using jpackage on linux.

The requirement for using getdown-launcher is that the provided directory should have write access. If I install the program to something like /var or /opt, I get this error message when running the launcher on that directory:

So how do I prevent this by using a write access directory? How do you use something like jpackage to make a .deb file to install to a write access enabled directory? Is there some standard directory in linux which has write access enabled by default? I would like to avoid writing a bash script to package with my application as much as possible to control the read/write access of folders.

Any help or suggestions on how to you use getdown with linux is helpful. Please help me out.