Unexpected behaviour from LSSerializer.writeToString

Question

I was trying to use LSSerializer to serialize a fragment of a larger XML document when I ran into some odd behaviour from Oracle's implementation.
This sample code shows LSSerializer being used to write a org.w3c.dom.Element XML fragment in both Oracle and Xerces:
<pre>
import java.io.ByteArrayInputStream;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSSerializer;
public class Test
public static final String xml = "&lt;foo>&lt;bar>abc&lt;/bar>&lt;baz>xyz&lt;/baz>&lt;/foo>";
public static void main(String[] args) throws Exception
// Oracle
System.out.println("Oracle LSSerializer:");
test(new oracle.xml.jaxp.JXDocumentBuilderFactory());
System.out.println();
// Xerces
System.out.println("Xerces LSSerializer:");
test(new com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl());
private static void test(DocumentBuilderFactory fac) throws Exception
DocumentBuilder b = fac.newDocumentBuilder();
Document d = b.parse(new ByteArrayInputStream(xml.getBytes()));
Element e = d.getDocumentElement();
System.out.println("Document root element: " + e.getNodeName());
DOMImplementationLS di = (DOMImplementationLS) d.getImplementation();
LSSerializer ser = di.createLSSerializer();
System.out.println(ser.writeToString(e));
</pre>
Here's the output:
<pre>
Oracle LSSerializer:
Document root element: foo
&lt;bar>abc&lt;/bar>&lt;baz>xyz&lt;/baz>
Xerces LSSerializer:
Document root element: foo
&lt;?xml version="1.0" encoding="UTF-16"?>
&lt;foo>&lt;bar>abc&lt;/bar>&lt;baz>xyz&lt;/baz>&lt;/foo>
</pre>
As you can see, Oracle's LSSerializer implementation serializes the children of the org.w3c.dom.Element, but not the element itself.
It's not hard to work around, but it really doesn't seem like the correct behaviour. It's certainly doesn't behave the way a reasonable developer would expect it to.

Answer 1

The XDK 10g implementation is slightly different from the Xerces implementation.
In XDK 10g, the node previous to the node to be output should be specified in the
writeToString() method.
Also in XDK 10g, SHOW_ELEMENT does not output the element text, in Xerces the element text is output.
Refer
http://www.oracle.com/technology/pub/notes/technote_dom.html