There is a workaround to this problem. From my experience with Jenkins ver. 1.629 (already on JDK 1.7), it looks like the issue only occurs when you create a new job using ‘Maven project’ template.
If you create a ‘Freestyle’ or ‘Multi-configuration’ project and configure Maven using ‘Invoke top-level Maven targets’ or ‘Invoke Maven 3’ build step, everything works fine.
I successfully tested with JDK 1.5 and 1.6 added to the main Jenkins config, which made them available in a JDK drop-down list of the job configuration. Note my Jenkins is running on JDK 1.7.
Therefore, I believe that the original problem is a Jenkins bug.
I can’t imagine why Jenkins would’ve prevented use of older JDKs in a project build, provided you can successfully built the project from the command line – it’s a tool after all.
Java 7 requirement from version 1.612 is a different matter related to running Jenkins itself.