Gunnar Morling You mean something like XMLInputFactory.newFactory("javax.xml.stream.XMLInputFactory", XmlParserHelper.class.getClassLoader()). That might be a solution. It depends on the nature of the underlying JAXB issue. I like the idea, but it needs more testing than just making the instance non static.

Making the instance non static clearly solved the problem, whereas fiddling with class loaders might cause other problems. The question is really, how much benefit do we get by "caching" the XMLInputFactory.