Is there a more elegant way to convert an XML Document to a String in Java than this code?

Question

Here is the code currently used.

public String getStringFromDoc(org.w3c.dom.Document doc)    {
        try
        {
           DOMSource domSource = new DOMSource(doc);
           StringWriter writer = new StringWriter();
           StreamResult result = new StreamResult(writer);
           TransformerFactory tf = TransformerFactory.newInstance();
           Transformer transformer = tf.newTransformer();
           transformer.transform(domSource, result);
           writer.flush();
           return writer.toString();
        }
        catch(TransformerException ex)
        {
           ex.printStackTrace();
           return null;
        }
    }

Answer 1

The transformer API is the only XML-standard way to transform from a DOM object to a serialized form (String in this case). As standard I mean SUN Java XML API for XML Processing.

Other alternatives such as Xerces XMLSerializer or JDOM XMLOutputter are more direct methods (less code) but they are framework-specific.

In my opinion the way you have used is the most elegant and most portable of all. By using a standard XML Java API you can plug the XML-Parser or XML-Transformer of your choice without changing the code(the same as JDBC drivers). Is there anything more elegant than that?

Answer 2

This is a little more concise:

try {
  Transformer transformer = TransformerFactory.newInstance().newTransformer();
  StreamResult result = new StreamResult(new StringWriter());
  DOMSource source = new DOMSource(doc);
  transformer.transform(source, result);
  return result.getWriter().toString();
} catch(TransformerException ex) {
  ex.printStackTrace();
  return null;
}

Otherwise you could use a library like XMLSerializer from Apache:

  //Serialize DOM
  OutputFormat format    = new OutputFormat (doc); 
  // as a String
  StringWriter stringOut = new StringWriter ();    
  XMLSerializer serial   = new XMLSerializer (stringOut, 
                                              format);
  serial.serialize(doc);
  // Display the XML
  System.out.println(stringOut.toString());

Answer 3

You could use XOM to perhaps do this:

org.w3c.dom.Document domDocument = ...;
nu.xom.Document xomDocument = 
    nu.xom.converters.DOMConverter.convert(domDocument);
String xml = xomDocument.toXML();

Answer 4

Relies on DOM Level3 Load/Save:

public String getStringFromDoc(org.w3c.dom.Document doc)    {
    DOMImplementationLS domImplementation = (DOMImplementationLS) doc.getImplementation();
    LSSerializer lsSerializer = domImplementation.createLSSerializer();
    return lsSerializer.writeToString(doc);   
}

Answer 5

This is an old question, but still relevent:

Using the questioner's method (which is the most commonly cited), on my box I got a 35-45ms conversion time.

By contrast, the LSSerializer and Apache XMLSerializer converted the same XML in 5-15ms