try {
  port.service_method();
} catch(Exception e) {
  e.PrintStackTrace();
}

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
  <SOAP-ENV:Header/>
  <SOAP-ENV:Body>
    <SOAP-ENV:Fault xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xml="http://www.w3.org/XML/1998/namespace">
      <faultcode xmlns="http://schemas.oblix.com/ws/2003/08/Faults">UndeliverableFault</faultcode>
      <faultstring>Cannot perform client request</faultstring>
      <detail/>
    </SOAP-ENV:Fault>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

package my.soap.Handlers;

import java.io.ByteArrayOutputStream;
import java.util.Collections;
import java.util.Set;
import javax.xml.namespace.QName;
import javax.xml.soap.SOAPMessage;
import javax.xml.ws.handler.MessageContext;
import javax.xml.ws.handler.soap.SOAPHandler;
import javax.xml.ws.handler.soap.SOAPMessageContext;

/**
 *
 * @author EDUARD
 */
public class testHandler implements SOAPHandler<SOAPMessageContext> {
    
    @Override
    public boolean handleMessage(SOAPMessageContext messageContext) {
        return true;
    }

    @Override
    public Set<QName> getHeaders() {
        return Collections.EMPTY_SET;
    }

    @Override
    public boolean handleFault(SOAPMessageContext messageContext) {
        try {
            SOAPMessage msg = messageContext.getMessage();

            QName fqn = msg.getSOAPBody().getFault().getFaultCodeAsQName();
            String namespace = fqn.getNamespaceURI();
            if (namespace == null || namespace.length() == 0) {
                namespace = "";
                QName newFqn = new QName(namespace, fqn.getLocalPart());
                msg.getSOAPBody().getFault().setFaultCode(newFqn);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }

    @Override
    public void close(MessageContext context) {
    }
}

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <soapenv:Header/>
  <soapenv:Body>
    <soapenv:Fault xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xml="http://www.w3.org/XML/1998/namespace" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <faultcode xmlns:ns1="http://schemas.oblix.com/ws/2003/08/Faults">
ns1:Client.GenericFault   </faultcode>
      <faultstring>
faultstring   </faultstring>
      <detail>
        <SourceMessage>  SourceMessage  </SourceMessage>
      </detail>
    </soapenv:Fault>
  </soapenv:Body>
</soapenv:Envelope>