Comment obtenir le chemin complet d'un noeud dans un fichier XML dans java?

Question

J'ai fichier XML analysé par XPath pour obtenir tous les paramètres, puis je veux obtenir le chemin complet à chaque paramètre, mais mon code ne fonctionne pas pour une raison quelconque. Le code:

ArrayList<String> names = new ArrayList<String>(); 
ArrayList<String> paths = new ArrayList<String>(); 
URL oracle = new URL("http://weather.yahooapis.com/forecastrss?w=2502265"); 
InputStream is = oracle.openStream(); 
org.w3c.dom.Document doc = null; 
DocumentBuilderFactory domFactory; 
DocumentBuilder builder; 
try { 
    domFactory = DocumentBuilderFactory.newInstance(); 
    domFactory.setNamespaceAware(true); 
    builder = domFactory.newDocumentBuilder(); 
    doc = builder.parse(is); 
} catch (Exception ex) { 
    System.err.println("unable to load XML: " + ex); 
} 

XPathFactory factory = XPathFactory.newInstance(); 
XPath xpath = factory.newXPath(); 
XPathExpression expr = xpath.compile("//*/@*"); 
Object result = expr.evaluate(doc, XPathConstants.NODESET); 
NodeList nl = (NodeList) result; 
for(int j=0 ; j < nl.getLength() ; j++){ 
    names.add(nl.item(j).getNodeName()); 
    Node node = nl.item(j); 
    ArrayList<String> parents = new ArrayList<String>(); 
    while(node.getParentNode() != null){ // it didn't even gone through this loop 
     parents.add(node.getNodeName()); 
     node = node.getParentNode(); 
    } 
    System.out.println(parents); 
}  

Answer 1

L'expression //*/@* retourne un NodeSet vide.

Le code ci-dessous récupérer les chemins dont vous avez besoin:

import org.w3c.dom.Attr; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 

public class SO { 

    @SuppressWarnings("nls") 
    public static void main(String[] args) throws Exception { 
     List<String> names = new ArrayList<>(); 
     URL oracle = 
     new URL("http://weather.yahooapis.com/forecastrss?w=2502265"); 
     InputStream is = oracle.openStream(); 
     org.w3c.dom.Document doc = null; 
     DocumentBuilderFactory domFactory; 
     DocumentBuilder builder; 
     try { 
     domFactory = DocumentBuilderFactory.newInstance(); 
     domFactory.setNamespaceAware(true); 
     builder = domFactory.newDocumentBuilder(); 
     doc = builder.parse(is); 
     } catch (Exception ex) { 
     System.err.println("unable to load XML: " + ex); 
     } 
     XPathFactory factory = XPathFactory.newInstance(); 
     XPath xpath = factory.newXPath(); 
     XPathExpression expr = xpath.compile("//*:*/@*"); 
     Object result = expr.evaluate(doc, XPathConstants.NODESET); 
     NodeList nl = (NodeList) result; 
     for(int j=0 ; j < nl.getLength() ; j++){ 
     names.add(nl.item(j).getNodeName()); 
     Node node = nl.item(j); 
     String path = "." + node.getNodeName() + " = " + node.getNodeValue(); 
     node = ((Attr)node).getOwnerElement(); 
     while(node != null) { 
      path = node.getNodeName() + '/' + path; 
      node = node.getParentNode(); 
     } 
     System.out.println(path); 
     } 
    } 
}