A CXF JAX-RS application I have uses the Jackson library to marshal POJOs to JSON. This works for the most part, but the other day it failed with a NPE when marshalling a deeply nested object into JSON.
After some investigation I found out that Jackson was included in Glassfish 3 (through Jersey) and after removing jackson-core-asl.jar, jackson-jaxrs.jar, jackson-mapper-asl.jar and jackson-xc.jar from the /modules directory of GF everything worked beautifully. I guess that Jackson 1.7.1 (included in GF3) had some bug that was fixed in the version shipped with my application (1.8).
Now the question is, why did I even have to do this in the first place? I would have thought libraries that are included in my war files should take presedence over any libraries in Glassfish's /modules directory.
Is there a cleaner way to do this than removing jars from the app server? Maybe there are other applications that depend on these jars ...
On a side note, the problem still exists with our GF2 container, but I cannot find any jackson libraries in the /lib folder (there is no /modules folder like in GF3). Any clues on where Jackson might be hiding in GF2 (if at all)?