In the first place, having to hard-code URLs into an application is bad
practice. Strongly resist putting absolute URLs inside your application code.
Doing so ties the application to one particular environment.

You can set up Apache to forward URLs of a certain pattern to another host or
directory. So you could keep your original relative paths and let the
deployment figure out whence to retrieve them.

The larger question is how it possibly makes sense to divide applications
where HTML files come from a separate logical host. Methinks this decision
requires more careful analysis and later rejection. From the point of view of
the application, all such resources should be local to the application.

Consider the WAR file that would install this app. Would it lack the HTML files?

- Lew