Hi, as I briefly mentioned this in today's IRC, I created a ticket CXF-3926 to fix or improve the current behavior.
jaxws 2.2 section 5.1.1 states: "When an invoke method returns null, it is considered that no response needs to be sent by service." CXF currently does not support this dynamic behavior but relies on the exchange's MEP information (req-resp or oneway) to decide whether to send no response. And the problem is that CXF is throwing an exception when a null is returned while the MEP is not set as oneway, as it tries to serialize the null object in its response/outbound processing. I am intending to introduce this dynamic behavior by slightly modifying JAXWSMethodInvoker's invoke method to switch to oneway in this case and set the correct response code. In addition, I am providing a new runtime property for jaxws to enable or disable this behavior. Please let me know if you have objections or alternative approaches. Thanks. regards, aki
