Java Xpath NameSpace Parsing - xpath

Question

Although I saw similar posts, I can't seem to solve this problem (so I am parsing the xml by hand and not using an xpath expression)... This is the XML I have...
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:tnew="http://PR_Library/TNeWebService">
<soapenv:Header/>
<soapenv:Body>
<tnew:ApercuenRequest>
<tnew:OpcionCarga>0</tnew:OpcionCarga>
<tnew:Sucursal>1</tnew:Sucursal>
<tnew:Vendedor>8000</tnew:Vendedor>
<tnew:CanalConsulta>1</tnew:CanalConsulta>
<tnew:UsuarioCarga>8000</tnew:UsuarioCarga>
<tnew:Comercio>0</tnew:Comercio>
<tnew:FechaEvaluacion>20140109</tnew:FechaEvaluacion>
<tnew:ModeloDeEvaluacion></tnew:ModeloDeEvaluacion>
<tnew:IdEvaluacion>3694852</tnew:IdEvaluacion>
<tnew:Dudosa>0</tnew:Dudosa>
<tnew:Exceptuado>1</tnew:Exceptuado>
<tnew:TipoDocumento>1</tnew:TipoDocumento>
<tnew:NumeroDocumento>5881040</tnew:NumeroDocumento>
<tnew:Sexo>F</tnew:Sexo>
<tnew:Rol>5</tnew:Rol>
<tnew:RelacionLaboral>5</tnew:RelacionLaboral>
<tnew:TipoEmpleado>0</tnew:TipoEmpleado>
<tnew:FechaIngresoEmpleo></tnew:FechaIngresoEmpleo>
<tnew:AntiguedadLaboral>0</tnew:AntiguedadLaboral>
<tnew:IngresoMensualAnalista>0</tnew:IngresoMensualAnalista>
<tnew:IngresoMensual>6000</tnew:IngresoMensual>
<tnew:EstadoCivil>4</tnew:EstadoCivil>
<tnew:FechaDeNacimiento>19540423</tnew:FechaDeNacimiento>
<tnew:SituacionVivienda>3</tnew:SituacionVivienda>
<tnew:DomicilioProvincia></tnew:DomicilioProvincia>
<tnew:DomicilioLocalidad></tnew:DomicilioLocalidad>
<tnew:NivelEstudios></tnew:NivelEstudios>
<tnew:RelacionConTN>1</tnew:RelacionConTN>
<tnew:FechaAltaAbogado></tnew:FechaAltaAbogado>
<tnew:MarcaAbogado>N</tnew:MarcaAbogado>
<tnew:Cdi></tnew:Cdi>
<tnew:Campana></tnew:Campana>
</tnew:ApercuenRequest>
</soapenv:Body>
</soapenv:Envelope>
And the following Java code...
private XPathFactory xpathFactory = null;
private XPath xpath = null;
private DocumentBuilderFactory factory = null;
private DocumentBuilder builder= null;
private XPathExpression expr;
private Node nodo = null;
private Node nodoAux = null;
private NodeList result = null;
private NodeList nodeList = null;
...
try {
xpathFactory = XPathFactory.newInstance();
xpath = xpathFactory.newXPath();
factory = DocumentBuilderFactory.newInstance();
builder= factory.newDocumentBuilder();
NamespaceContext context = new NameSpaceNevada();
xpath.setNamespaceContext(context);
}
catch (Exception e) {
}
...
evaluarExpresion(documentoXML,"/soapenv:Envelope/soapenv:Body/tnew:ApercuenRequest/tnew:OpcionCarga")
private String evaluarExpresion(Document documentoXML, String expresion) throws Exception{
try {
expr = xpath.compile(expresion);
result = (NodeList)expr.evaluate(documentoXML, XPathConstants.NODESET);
System.out.println((result.item(0)!=null?result.item(0).getNodeName():"") + " ->>>> " + (result.item(0).getFirstChild()!=null?result.item(0).getFirstChild().getNodeValue():""));
return result.item(0).getFirstChild()!=null?result.item(0).getFirstChild().getNodeValue():null;
}
catch (Exception e) {
e.printStackTrace();
return null;
}
}
And I can't seem to get the "0" value as you see it in the XML... I have tried a lot of things... I'll be watching... The thing is, I can parse it manualy but the joke is doing it through xpath expressions so I can save code...
Hope I made me understood...
The getNamespaceURI method from the NameSpaceNevada object is as follows:
public String getNamespaceURI(String prefix) {
if (prefix == null) {
throw new IllegalArgumentException("No prefix provided!");
} else if (prefix.equals(XMLConstants.DEFAULT_NS_PREFIX)) {
return "http://univNaSpResolver/book";
} else if (prefix.equals("soapenv")) {
return "http://schemas.xmlsoap.org/soap/envelope/";
} else if (prefix.equals("tnew")) {
return "http://PR_Library/TNeWebService";
} else {
return XMLConstants.NULL_NS_URI;
}
}

Answer 1

Rather than evaluating the expression as a node set and then doing complex DOM manipulations to extract the text value, you could just evaluate the expression as a string in the first place.
expr.evaluate(documentoXML);
would evaluate the expression and use XPath rules to convert the result to a String, which in this case would give you the text content of the first (in fact the only) tnew:OpcionCarga element.
But the real reason why it is not working is that Java's DocumentBuilderFactory is non-namespace-aware by default (a very bad design decision in many people's eyes, but one that now cannot be corrected without breaking backwards compatibility) - you must do
factory.setNamespaceAware(true);
before you call .newDocumentBuilder() in order to create a namespace-aware parser.