调用WEBSERVICE出现空指针异常问题

[devingel]

调用代码如下:WEBSERVICE是通的,请问是什么原因啊,急....
String endpoint="http://10.71.77.247/HZWGGZCLSERVICE/HZExceptionDisposeService.asmx";



Service service = new Service();

Call call = (Call)service.createCall();



call.setTargetEndpointAddress(new java.net.URL(endpoint));

call.setOperationName(new QName("http://10.71.77.247/hzwggzclservice","SendExceptionInfo"));



call.addParameter("WorksheetNumber",org.apache.axis.encoding.XMLType.XSD_STRING,javax.xml.rpc.ParameterMode.IN);

call.addParameter("TelephoneNumber",org.apache.axis.encoding.XMLType.XSD_STRING,javax.xml.rpc.ParameterMode.IN);

call.setReturnType(org.apache.axis.encoding.XMLType.XSD_STRING);

call.setUseSOAPAction(true);

call.setSOAPActionURI("http://10.71.77.247/hzwggzclservice");





res = (String)call.invoke(new Object[]{bid,called});



System.out.println( "result is ---------------------" + res + "----------.");