mule 传递参数给webservice?报错

@huangweibing 你好，想跟你请教个问题：

我看了你的mule传递参数给cxf的webservice.为什么我一个参数也报错？？

local part cannot be "null" when creating a QName. Failed to route event via endpoint: org.mule.module.cxf.CxfOutboundMessageProcessor. Message payload is of type: NullPayload

我的配置

 <flow name="transportVars" doc:name="transportVars">
    <http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8099" path="transService" doc:name="HTTP Endpoint"/>
    <http:body-to-parameter-map-transformer doc:name="Body to Parameter Map"/>
    <flow-ref name="out_validatorService" doc:name=""/>
    </flow>
    <sub-flow name="out_validatorService" doc:name="out_validatorService">
    <set-payload value="#[payload['canshu']]" doc:name="userAcct"/>
    <outbound-endpoint exchange-pattern="request-response" address="wsdl-cxf:http://localhost:8090/helloServiceRemote?wsdl&mthod=sayHello" doc:name="remoteService"/>
       <!--  <append-string-transformer message="app" doc:name="Append String"/> -->
    </sub-flow>