As mentioned earlier, when WSDL was created for our Course web service, the argument for the getCourse operation name was created as arg0. You can verify this by browsing to http://localhost:8080/CourseMgmtWSProject/courseService?xsd=1 and checking the getCourse type:

<xs:complexType name="getCourse"> 
     <xs:sequence> 
         <xs:element name="arg0" type="xs:int"/> 
     </xs:sequence> 
</xs:complexType> 

Thus, the client-side-generated code (by wsimport) in CourseManagementService.getCourse also names the argument as arg0. It would be nice to give a meaningful name to arguments. This could be done easily be adding the @WSParam annotation in our web service implementation class, CourseManagementService:

public Course getCourse(@WebParam(name="courseId") int courseId) {...} 

Restart Tomcat after this change and browse to the WSDL schema URL (http://localhost:8080/CourseMgmtWSProject/courseService?xsd=1) again. You should now see a proper argument name in the getCourse type:

<xs:complexType name="getCourse"> 
     <xs:sequence> 
         <xs:element name="courseId" type="xs:int"/> 
     </xs:sequence> 
</xs:complexType> 

Generate the client-side code again by using wsimport, and you will see that argument of the getCourse method is named courseId.