webservice报Error reading XMLStreamReader异常


String endpoint = "a?wsdl"; Service service = new Service(); Call call = (Call) service.createCall();
call.setTargetEndpointAddress(endpoint);
call.setOperationName("FechZWD"); call.addParameter("CC", org.apache.axis.encoding.XMLType.XSD_DATE,
javax.xml.rpc.ParameterMode.IN);
call.addParameter("CZ", org.apache.axis.encoding.XMLType.XSD_DATE,
javax.xml.rpc.ParameterMode.IN); SOAPHeaderElement soapHeaderElement = new SOAPHeaderElement(
new javax.xml.namespace.QName(
"as"),
"SMSSoapHeader");
soapHeaderElement
.setNamespaceURI("a");
soapHeaderElement.setObjectValue(null);
soapHeaderElement.addChildElement("Username").setValue("Username");
soapHeaderElement.addChildElement("Password").setValue("Password");
call.addHeader(soapHeaderElement);
call.setUsername("Username");
call.setPassword("Password");

  
call.setReturnType(org.apache.axis.encoding.XMLType.XSD_SCHEMA);   Object[] params = new Object[2];
params[0] = "a";
params[1] = "b";
Object res = call.invoke(params);
Schema schema = (Schema) res;
在 Object res = call.invoke(params); 报Error reading XMLStreamReader.