Examples of good JPA Java Desktop Application

wish helps you SharpDevelop is an open source Development IDE for .NET very much like VS.NET written in .NET (iirc it still has some pinvokes, but it is all managed code) and is quite large and feature complete.
You can even get the source code for it to look at.

To fix the issue you can do A little bit old, but quite well written, with plenty of examples: http://homepage.mac.com/bradster/iarchitect/shame.htm

help you fix your problem This use to be a good showcase for that.
Swing Sightings at Sun

I hope this helps . JXMapViewer was a part of SwingLabs, which brought us also SwingX, but with java.net no longer available, it's webpage is no longer reachable.
There is a fork of JXMapViewer named JXMapViewer2, which seems better maintained and offers also examples how to use it: https://github.com/msteiger/jxmapviewer2

This might help you See our DMS Software Reengineering Toolkit. This is a program transformation engine designed to accept arbitrary language definitions (your "old codebase"), carry out arbitrary analyses, and then apply transformations based on those analyses. Construction of DMS started in 1995, so it has had considerable time to be applied and used in practice.
DMS has been used to define DSLs and transform them to other languages. It has been used to "define" (implement) the specification of many classic programming languages (C, C++, C#, COBOL, Java, PHP, JavaScript, ....) and carry out analyses of those, and transform the code in those languages to provide improved versions of the original program. The tasks it has been applied to are commercial, practical, and the results in use. It has been used to translate legacy languages into more modern ones.