UnsupportedClassVersionError when running with 1.5 JDK

[Vincent]

Ubuntu release: 12.04
Package version: 2.11.0-4

When building a Java project with ant, the Xerces implementation from this package is being used. However, it's been compiled with binary compatibility set to 1.6, so an UnsupportedClassVersionError will be thrown if we try to run ant with a 1.5 JDK.

When a project claims to be compatible with Java 1.5, it is necessary to build it with a 1.5 JDK to make sure that no class or method that is new in Java 1.6 is being used.

As indicated in the README file provided with the source code of Xerces 2.11, a JDK of version as low as 1.2 should be enough to build it.

It would be good if Xerces could be recompiled with binary compatibility set to 1.5 or lower so that we can use it with older JDKs.

[Logan Rosen (logan)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. However, I am closing it because the bug has been fixed in the latest development version of Ubuntu - Quantal Quetzal.

This is a significant bug in Ubuntu. If you need a fix for the bug in previous versions of Ubuntu, please do steps 1 and 2 of the SRU Procedure [1] to bring the need to a developer's attention.

[1]: https://wiki.ubuntu.com/StableReleaseUpdates#Procedure

This bug was fixed in Quantal via Bug 1012062.

[Logan Rosen (logan)]

Whoops, I meant Bug 999749 for that last part.

[Vincent (vhennebert)]

I'm not sure I can be bothered to launch the procedure for a SRU. I found a workaround for the problem that has been working for me so far. I'm posting it here in case anybody else stumbling upon this issue is interested:
Get the xercesImpl-2.9.1.jar from an earlier version of Ubuntu (I took mine from 10.04) and put it in the jre/lib/ext directory of your 1.5 JDK. That's it!