user393381 user393381 - 6 months ago 28
Java Question

builder.parse((new StringReader(xml)) returns DeferredDocumentImpl

I am trying to understand what mistake I could have made but can't find the solution.

public static Document getXMLFromString(String xml) {
org.w3c.dom.Document doc = null;
try {
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder;
builder = factory.newDocumentBuilder();
doc = (org.w3c.dom.Document) builder.parse(new InputSource(
new StringReader(xml)));
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
return doc;
}


I did import org.w3c.dom.Document

I am calling this method here:


private Node getAuthToken(SOAPMessage responseAuth) throws SOAPException,
TransformerException, ParserConfigurationException, IOException,
SAXException {
String s = indentXML(responseAuth.getSOAPPart().getContent());
Document doc = getXMLFromString(s);
NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
return authTokenNodeList.item(0);
}


The NodeList is empty.

After researching on the web, everybody uses this code to parse a string to a Document. I do not have any exception but after calling the method parse(), the value of doc is set to [#document: null] DeferredDocumentImpl.

I am using everything from the org.w3c.dom.

xml is a string that contains

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Header>
<context xmlns="urn:zimbra">
<session id="36" type="admin">36</session>
<change token="251"/>
</context>
</soap:Header>
<soap:Body>
<AuthResponse xmlns="urn:zimbraAdmin">
<authToken>...</authToken>
<lifetime>...</lifetime>
<a n="zimbraIsDomainAdminAccount">false</a>
<session id="36" type="admin">36</session>
</AuthResponse>
</soap:Body>
</soap:Envelope>


Here is how I built the string after a SOAP call:

String xml = indentXML(responseAuth.getSOAPPart().getContent());


What am I doing wrong?

This is what I am trying to do in a simple way:

StringBuilder soapResponse = new StringBuilder(...
...
...
);

org.w3c.dom.Document doc = null;
try {
DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
factory.setNamespaceAware(true);
DocumentBuilder builder;
builder = factory.newDocumentBuilder();
doc = (org.w3c.dom.Document) builder.parse(new InputSource(
new StringReader(soapResponse.toString())));
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
}
NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
Node n = authTokenNodeList.item(0);
String s = n.getNodeValue();

Answer

EDIT: Looking at your updated code, I think this is the problem:

String s = n.getNodeValue();

If you look at the docs for Node you'll see that getNodeValue() is defined to return null for elements... hence the problem. My sample code uses getTextContent() instead, which works fine.


It looks like that's just going to defer expanding in-memory objects until they're required.

Have you tried calling methods on the returned document rather than just looking in the debugger? I suspect everything is actually working as intended. If not, please post a short but complete program which shows it misbehaving. (Note that in the sample you've given, you haven't even shown how builder is set, and you haven't used factory.)

EDIT: The code you've given works for me. Here's a quick-and-dirty - but importantly, complete - program (using Guava to load the XML file into a string) which shows the node being found successfully:

import org.w3c.dom.*;
import org.xml.sax.*;
import java.text.*;
import java.util.*;
import javax.xml.parsers.*;
import java.io.*;
import com.google.common.base.*;
import com.google.common.io.*;

public class Test {

    public static void main(String[] args) throws Exception {
        String xml = Files.toString(new File("test.xml"), Charsets.UTF_8);
        Node node = getAuthToken(xml);
        System.out.println(node.getTextContent());
    }

    private static Node getAuthToken(String xml) throws Exception {
        Document doc = getXMLFromString(xml);
        NodeList authTokenNodeList = doc.getElementsByTagName("authToken");
        return authTokenNodeList.item(0);
    }

    public static Document getXMLFromString(String xml) throws Exception {
        Document doc = null;
        DocumentBuilderFactory factory = DocumentBuilderFactory
            .newInstance();
        factory.setNamespaceAware(true);
        DocumentBuilder builder;
        builder = factory.newDocumentBuilder();
        doc = builder.parse(new InputSource(new StringReader(xml)));
        return doc;
    }
}