Receiving null result from SOAP request

I'm trying to make a soap request to a Brazilian government endpoint and I'm facing some trouble.

They make the following wsdl available: https://mdfe-homologacao.svrs.rs.gov.br/ws/MDFeRecepcaoSinc/MDFeRecepcaoSinc.asmx?wsdl

I then generated the corresponding stub using wsimport tool, which consists on the following:

• MDFeRecepcaoSinc.java
• MdfeRecepcaoResult.java
• MDFeRecepcaoSincSoap12.java (interface)
• ObjectFactory.java
• package-info.java

Then, on my Java application, I did the following:

            ObjectFactory of = new ObjectFactory();
            JAXBElement<String> jaxb = of.createMdfeDadosMsg("<soap:Envelope xmlns:soap=\"http://www.w3.org/2003/05/soap-envelope\" xmlns:mdf=\"http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc\"><soap:Header/><soap:Body><mdf:mdfeDadosMsg>?</mdf:mdfeDadosMsg></soap:Body></soap:Envelope>");
            MDFeRecepcaoSinc recepcao = new MDFeRecepcaoSinc();
            MDFeRecepcaoSincSoap12 soap = recepcao.getMDFeRecepcaoSincSoap12(
//                  new AddressingFeature(true),
//                  new MTOMFeature(false),
//                  new RespectBindingFeature(true)
            );
            System.out.println(soap.mdfeRecepcao(jaxb.getValue()).getContent());

Although the only result I'm getting, independent of the body text, is [[retMDFe: null]].

I managed to make it work on SoapUI with this exact same request envelope and it returns a correct xml with a few tags inside retMDFe.

It appears to be connecting to their server from my Java client since the tag retMDFe isn't present in the WSDL file or any stub I generated, and since I don't receive the 403 - Forbidden error anymore (configured the system keystore correctly).

Unfortunately, this webservice only allows connections issued with a digital certificate.

I'm suspecting the error may be from the mapping from the endpoint to the MdfeRecepcaoResult class. I've tried a few things:

• enabling different WebServiceFeatures on the constructor of recepcao.getMDFeRecepcaoSincSoap12, although only MTOMFeature as true returned something different: Client received SOAP Fault from server: Server was unable to process request. ---> Data at the root level is invalid. Line 1, position 1. Please see the server log to find more detail regarding exact cause of the failure.;
• changing mdfeRecepcao return type from MdfeRecepcaoResult to String, which gave me an empty string;
• commenting annotations on mdfeRecepcao, which continued to give me the [[retMDFe: null]] response;
• also tried passing different xml strings directly to soap.mdfeRecepcao() method, but got the same results.

What am I possibly doing wrong here? Thank you for your time!

Edit 1:

• Declaration of mdfeRecepcao inside MDFeRecepcaoSincSoap12 interface:

    /**
     * 
     * @param mdfeDadosMsg
     * @return
     *     returns br.inf.portalfiscal.mdfe.wsdl.mdferecepcaosinc.MdfeRecepcaoResult
     */
    @WebMethod(action = "http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc/mdfeRecepcao")
    @WebResult(name = "mdfeRecepcaoResult", targetNamespace = "http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc", partName = "mdfeRecepcaoResult")
    public MdfeRecepcaoResult mdfeRecepcao(
        @WebParam(name = "mdfeDadosMsg", targetNamespace = "http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc", partName = "mdfeDadosMsg")
        String mdfeDadosMsg);

• Declaration of createMdfeDadosMsg inside ObjectFactory class

    /**
     * Create an instance of {@link JAXBElement }{@code <}{@link String }{@code >}}
     * 
     */
    @XmlElementDecl(namespace = "http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc", name = "mdfeDadosMsg")
    public JAXBElement<String> createMdfeDadosMsg(String value) {
        return new JAXBElement<String>(_MdfeDadosMsg_QNAME, String.class, null, value);
    }

Edit 2:

• wsimport version: wsimport version "2.2.9"

• wsimport generated files:

br/inf/portalfiscal/mdfe/wsdl/mdferecepcaosinc/MDFeRecepcaoSinc.java
br/inf/portalfiscal/mdfe/wsdl/mdferecepcaosinc/MDFeRecepcaoSincSoap12.java
br/inf/portalfiscal/mdfe/wsdl/mdferecepcaosinc/MdfeRecepcaoResult.java
br/inf/portalfiscal/mdfe/wsdl/mdferecepcaosinc/ObjectFactory.java
br/inf/portalfiscal/mdfe/wsdl/mdferecepcaosinc/package-info.java

I use the following to produce the stubs: wsimport -extension -keep -verbose MDFeRecepcaoSinc.wsdl and it only gives a single warning: [WARNING] a porta SOAP \"MDFeRecepcaoSincSoap12\": usa um bind de SOAP 1.2 não padrão. linha 40 de file:/home/teste-progra/tiago/backup/mdfe/wsimport-test/MDFeRecepcaoSinc.wsdl (which means that the port used by the web service does not use a conventional (or default) bind for SOAP 1.2, and has to do with the following line in the wsdl:

    <wsdl:port name="MDFeRecepcaoSincSoap12" binding="tns:MDFeRecepcaoSincSoap12">

I'm not sure if that's of any use though, hence the connection is effectively being held on.

Edit 3: I'm able to successfully read the HTTP request and response with System.setProperty("com.sun.xml.internal.ws.transport.http.client.HttpTransportPipe.dump", "true"); and its content is the following:

---[HTTP request - https://mdfe.svrs.rs.gov.br/ws/MDFeRecepcaoSinc/MDFeRecepcaoSinc.asmx]---
Accept: application/soap+xml, multipart/related
Content-Type: application/soap+xml; charset=utf-8;action="http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc/mdfeRecepcao"
User-Agent: JAX-WS RI 2.2.9-b130926.1035 svn-revision#5f6196f2b90e9460065a4c2f4e30e065b245e51e
<?xml version='1.0' encoding='UTF-8'?><S:Envelope xmlns:S="http://www.w3.org/2003/05/soap-envelope"><S:Body><mdfeDadosMsg xmlns="http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc">&lt;soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:mdf="http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc"&gt;&lt;soap:Header/&gt;&lt;soap:Body&gt;&lt;mdf:mdfeDadosMsg&gt;?&lt;/mdf:mdfeDadosMsg&gt;&lt;/soap:Body&gt;&lt;/soap:Envelope&gt;</mdfeDadosMsg></S:Body></S:Envelope>--------------------

---[HTTP response - https://mdfe.svrs.rs.gov.br/ws/MDFeRecepcaoSinc/MDFeRecepcaoSinc.asmx - 200]---
null: HTTP/1.1 200 OK
Cache-Control: private, max-age=0
Content-Length: 586
Content-Type: application/soap+xml; charset=utf-8
Date: Fri, 27 Sep 2024 18:54:54 GMT
Server: Microsoft-IIS/10.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><mdfeRecepcaoResult xmlns="http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc"><retMDFe xmlns="http://www.portalfiscal.inf.br/mdfe" versao="3.00"><tpAmb>1</tpAmb><cUF>43</cUF><verAplic>RS20240710093839</verAplic><cStat>244</cStat><xMotivo>Rejeição: Falha na descompactação da área de dados</xMotivo></retMDFe></mdfeRecepcaoResult></soap:Body></soap:Envelope>--------------------

So I'm actually receiving content under retMDFe tag! I just can't get it mapped properly to MdfeRecepcaoResult.

I've tried setting the WS return as String so I could print it directly, which gave me an empty result.

Per instance, which class actually implements this interface?

You are not correctly marshalling the element here.

// Create the ObjectFactory
ObjectFactory of = new ObjectFactory();

// Create the JAXBElement with the correct inner XML content
String innerXmlContent = "<mdfeDadosMsg xmlns=\"http://www.portalfiscal.inf.br/mdfe/wsdl/MDFeRecepcaoSinc\">...</mdfeDadosMsg>";
JAXBElement<String> jaxb = of.createMdfeDadosMsg(innerXmlContent);

// Create the service and get the SOAP port
MDFeRecepcaoSinc recepcao = new MDFeRecepcaoSinc();
MDFeRecepcaoSincSoap12 soap = recepcao.getMDFeRecepcaoSincSoap12(
        new AddressingFeature(true),
        new MTOMFeature(false),
        new RespectBindingFeature(true)
);

MdfeRecepcaoResult response = soap.mdfeRecepcao(jaxb.getValue()); 
List<Element> list = response.getContent(); 
for(Element element : list) {
    System.out.println(element.getTextContent());
}