How to recompile old Spring 2.5 application?

We have in use an old application running on Spring 2.5 and Jboss 4.2.3 which hasn't been modified for years. It will be replaced with a new application, developed in our current stack, in a foreseable future. Until then, we need to provide very basic maintenance and updates.

I have succeded to setup a working development environment with newer JRE and MySQL versions. Now I need to test that we are able to modify the original source and recompile it the WAR package for deployment.

I would appreciate information on the following topics:

  • Which JDK version should I use? Can I use Java 7 or do I need a 1.6 version?
  • Where can I find build scripts or samples? (there's nothing such as build.xml in the project).
  • Any other tip that would be helpful.

Thanks in advance.