Details
Description
If the method has no arguments, some client implementation may not send the <params> tag.
in this situation, apache xml-rpc server will cause a NullPointerException.
i try to trace the function call and it seems that xml-rpc uses the <params> tag as a clue to lazy
initailize the ArrayList that containing method call parameters, so if no <params> tag, the list
will never be created, and result in a NPE.