stax NoSuchElementException xml XMLConstants xml namespace NamespaceContext defaultnamespacecontext namespacecontext defaultnamespacecontext default_namespace_context_instance defaultnamespacecontext defaultnamespacecontext defaultnamespacecontext getinstance default_namespace_context_instance getnamespaceuri prefix prefix illegalargumentexception xmlconstants.xml_ns_prefix.equals prefix xmlconstants.xml_ns_uri xmlconstants.xmlns_attribute.equals prefix xmlconstants.xmlns_attribute_ns_uri xmlconstants.null_ns_uri getprefix namespaceuri namespaceuri illegalargumentexception xmlconstants.xml_ns_uri.equals namespaceuri xmlconstants.xml_ns_prefix xmlconstants.xmlns_attribute_ns_uri.equals namespaceuri xmlconstants.xmlns_attribute getprefixes namespaceuri namespaceuri illegalargumentexception xmlconstants.xml_ns_uri.equals namespaceuri hasnext hasnext nosuchelementexception xmlconstants.xml_ns_prefix remove unsupportedoperationexception xmlconstants.xmlns_attribute_ns_uri.equals namespaceuri hasnext hasnext nosuchelementexception xmlconstants.xmlns_attribute remove unsupportedoperationexception collections.empty_list.iterator