Want to translate the old Java soap.jar style code to something modern

I have 10 year old Java code to call an outdated SOAP authentication service. WSDL is RPC: ENCODED and contains many typos. I was hoping to easily convert the old code to Axis 1.4 or something like that, but ran into snags. All I watched wanted to use WSDL. Can someone help translate this into modern code that does not require faulty WSDL?

Here's the SOAP call section:

    SOAPMappingRegistry soapmappingregistry = new SOAPMappingRegistry();
    BeanSerializer beanserializer = new BeanSerializer();

    soapmappingregistry.mapTypes(Constants.NS_URI_SOAP_ENC, new QName(
            "urn:xml-soap-session-demo", "authenticationresult"),
            AuthenticationResult.class, beanserializer, beanserializer);
    Call call = new Call();
    call.setSOAPMappingRegistry(soapmappingregistry);
    call.setTargetObjectURI("urn:Security");
    call.setMethodName("authenticate");
    call.setEncodingStyleURI(Constants.NS_URI_SOAP_ENC);
    Vector<Object> vector = new Vector<Object>();
    vector.addElement(new Parameter("app", String.class, "PHS", null));
    vector.addElement(new Parameter("user", String.class, userName, null));
    vector.addElement(new Parameter("password", String.class, password, null));
    vector.addElement(new Parameter("encryption", Integer.class, new Integer(0), null));
    call.setParams(vector);
    Response response = null;
    URL endpointURL = new URL(endpoint);
    response = call.invoke(endpointURL, "");
    if (!response.generatedFault()) {
        Parameter parameter = response.getReturnValue();
        Object obj = parameter.getValue();
    ...
    }

Many thanks.