Have you tried defining the fault in your wsdl file and then using wsimport to have the JAXB artifacts generated for you?
Example that I think should work:
wsdl:
<?xml version="1.0" encoding="UTF-8"?>
<definitions
name="SubtractNumbers"
targetNamespace="http://duke.example.org"
xmlns:tns="http://duke.example.org"
xmlns="http://schemas.xmlsoap.org/wsdl/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/">
<types>
<xsd:schema
xmlns="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://duke.example.org"
elementFormDefault="qualified">
<complexType name="subtractNumbersResponse">
<sequence>
<element name="return" type="xsd:int" />
</sequence>
</complexType>
<element name="subtractNumbersResponse" type="tns:subtractNumbersResponse"/>
<complexType name="subtractNumbers">
<sequence>
<element name="arg0" type="xsd:int" />
<element name="arg1" type="xsd:int" />
</sequence>
</complexType>
<element name="subtractNumbers" type="tns:subtractNumbers"/>
<element name="permissionDeniedFault">
<complexType>
<sequence>
<element name="message" type="xsd:string"/>
</sequence>
</complexType>
</element>
</xsd:schema>
</types>
<message name="subtractNumbers">
<part name="parameters" element="tns:subtractNumbers" />
</message>
<message name="subtractNumbersResponse">
<part name="result" element="tns:subtractNumbersResponse" />
</message>
<message name="permissionDeniedException">
<part name="permissionDeniedFault" element="tns:permissionDeniedFault"/>
</message>
<portType name="SubtractNumbersPortType">
<operation name="subtractNumbers">
<input message="tns:subtractNumbers" />
<output message="tns:subtractNumbersResponse" />
<fault name="permissionDeniedFault" message="tns:permissionDeniedException" />
</operation>
</portType>
<binding name="SubtractNumbersBinding" type="tns:SubtractNumbersPortType">
<soap:binding transport="http://schemas.xmlsoap.org/soap/http" style="document" />
<operation name="subtractNumbers">
<soap:operation soapAction="" />
<input>
<soap:body use="literal" />
</input>
<output>
<soap:body use="literal" />
</output>
<fault name="permissionDeniedFault">
<soap:fault use="literal" name="permissionDeniedFault" />
</fault>
</operation>
</binding>
<service name="SubtractNumbersService">
<port name="SubtractNumbersPort" binding="tns:SubtractNumbersBinding">
<soap:address location="REPLACE_WITH_ACTUAL_URL" />
</port>
</service>
</definitions>
Generated fault/exception related artificats:
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"message"
})
@XmlRootElement(name = "permissionDeniedFault")
public class PermissionDeniedFault {
@XmlElement(required = true)
protected String message;
/**
* Gets the value of the message property.
*
* @return
* possible object is
* {@link String }
*
*/
public String getMessage() {
return message;
}
/**
* Sets the value of the message property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void setMessage(String value) {
this.message = value;
}
}
@WebFault(name = "permissionDeniedFault", targetNamespace = "http://duke.example.org")
public class PermissionDeniedException
extends Exception
{
/**
* Java type that goes as soapenv:Fault detail element.
*
*/
private PermissionDeniedFault faultInfo;
/**
*
* @param message
* @param faultInfo
*/
public PermissionDeniedException(String message, PermissionDeniedFault faultInfo) {
super(message);
this.faultInfo = faultInfo;
}
/**
*
* @param message
* @param faultInfo
* @param cause
*/
public PermissionDeniedException(String message, PermissionDeniedFault faultInfo, Throwable cause) {
super(message, cause);
this.faultInfo = faultInfo;
}
/**
*
* @return
* returns fault bean: provider.server.PermissionDeniedFault
*/
public PermissionDeniedFault getFaultInfo() {
return faultInfo;
}
}
Implementation class:
@WebService (serviceName = "SubtractNumbersService",
portName = "SubtractNumbersPort",
endpointInterface = "provider.server.SubtractNumbersPortType" )
public class SubtractNumbersImpl {
public int subtractNumbers(int arg1, int arg2) throws PermissionDeniedException {
PermissionDeniedFault permissionDeniedFault = new PermissionDeniedFault();
permissionDeniedFault.setMessage("Your custom message here explain why permission was denied.");
throw new PermissionDeniedException("Permission denied.", permissionDeniedFault);
}
}