Java web applet/form reverse engineering

Question

I'm supposed to create a new product based on a discontinued product. The problem is the original programmers of the discontinued product lost the source code (yeah, awesome).

The software is run through a web browser. When I go to their url, a window pops up with the title "Oracle Developer Forms Runtime". I'm not sure if this is an applet or Java plugin or whatever, because I've only been developing Java "command line" applications.

Is there any luck I can see what's being called and returned between the app and the server so I can imitate something similar? If so, what tools should I be looking into?

Answer 1

Given my knowledge of Oracle Forms (which is quite limited by the way), Peter Tillemans's answer is in the right direction. The applet is merely a thick-client for the screens built in Oracle Forms.

If you want to recover the source code, you'll need to look for the *.fmb files (the Forms Builder files that contain the source code) built for the application. These would contain the PL/SQL source code as well as the screen layout, and would have to be opened using the Oracle Forms Builder tool. You might also want to acquire a copy of any PL/SQL source code that is meant to run on the database server.

If you've lost the FMB files, then you might have to figure out a way to recover the sources from the compiled FMX files, that is actually used at runtime by the Forms Server. I'm not aware of any decompilers for these.

In my opinion, decompiling the applet is an exercise in futility, for that is a part of the Oracle Forms Java client (and is part of the Oracle Forms product itself), meant to be deployed on a web server. None of the screens developed as part of the application, are actually compiled into Java classes; the applet actually performs the job of receiving UI information from the Oracle Forms Server and displaying it on the screen. It is the Forms Server where the heavy lifting occurs; all business logic and transaction management occurs in this server, and this is what you should be after (and it can be found in the FMB and FMX files).

There are other files that might also need to be accounted for.

• PLL files would contain PL/SQL source code that is in use across multiple forms.
• MMB files would contain menu modules.