Mandatory return parameter in Web Service

Question

Hello,
Do you know how to set a return parameter mandatory in a Web Service using an Enterprise JavaBean (Netweaver 2004s)? The method has 2 return parameters in the WSDL:
<xs:complexType name="SignResponse">
<xs:sequence>
  <xs:element name="nfeid" type="xs:string" nillable="true" minOccurs="0"/>
  <xs:element name="status" type="xs:int"/>
</xs:sequence>
</xs:complexType>
The status parameter is mandatory, the other is optional (minOccurs="0"). But we also need the nfeid mandatory for the XI-mapping.
Java:
public class SignResponse implements Serializable {
     public SignResponse(String s) {
          status = -1;
          nfeid = s;
Business Method.
public SignResponse sign(
Regards, Volker

Answer 1

I have also tried to return a Document in my webservices but it doesn't work. From what I understood (I am a newbee), webservices must return primitive data type values (int, String, etc.).
Finally, I changed my webservices so that they return a String :
Document documentXML                        = new com.sun.xml.tree.XmlDocument();
//Return the XML document into string
StringWriter writer                         = new StringWriter();
((XmlDocument)documentXML)                    .write(writer);
return writer                                 .toString();