Classes might not come from files: they may be loaded from the
network, or dynamically generated.

   - Oliver

clazz.getProtectionDomain().getCodeSource().getLocation()

You might not get meaningful information from this.

Tom Hawtin

Why (do you think you need to know)?  What ability
are you attempting to bring to the end user, by identifying
where the class files reside?

Try something like:

    private String getPath(Class cls) {
        String cn = cls.getName();
        String rn = cn.replace('.', '/') + ".class";
        String path =
getClass().getClassLoader().getResource(rn).getPath();
        int ix = path.indexOf("!");
        if(ix >= 0) {
            return path.substring(0, ix);
        } else {
            return path;
        }
    }

Arne