Is there an implementation of the rpmbuild that is written in Java?
Alas, the build server is running on Windows and yet the build process
for a particular Java-based application needs to generate an rpm via
which to be able to install it on RedHat Linux servers.
The build server (Hudson) needs to stay on Windows OS as it also runs
msbuild to build various C# .NET solution projects.
Have a look at redline-rpm, a pure Java RPM Library that provides an Ant task: