[jdom-interest] Creating new XML documents from existing XML document(s)

Thu Jul 28 11:22:44 PDT 2005

Hello,

I am trying to create a new XML document from an existing XML document using JDOM, but am unable to do so. I want to take the root element of an existing document and use it as the root element of a new XML document. The code I am using is as follows:

--------------------------------

import org.jdom.*;
import org.jdom.input.*;
import org.jdom.output.*; 
import org.jdom.transform.*;
import java.io.StringReader;

public class JDOMTest
{
    public static void main(String[] args) throws JDOMException {
        mytest();
    }

    public static void mytest() {
        try {
            // XML String. Elements from this will form the basis of the new XML document
            String xmlString="<?xml version=\"1.0\" encoding=\"UTF-8\"?><note><to>Tove</to><from>Jani</from><heading>Reminder</heading><body>Don't forget me this weekend!</body></note>";
            SAXBuilder builder = new SAXBuilder();
            // Extract the root element from the XML string
            Document test = builder.build(new StringReader(xmlString));
            Element root = test.getRootElement(); 

            // Create a new XML document and set its root element
            Document newDocument = new Document();
            newDocument.setRootElement(root);

            System.out.println("Complete!");
        }
        catch (Exception e) {
            System.out.println("General Exception ocurred : "+e);
        }
    }
}

------------------------------

This compiles without error, but every time I run it I get the following error:

------------------------------
> java JDOMTest
General Exception ocurred : org.jdom.IllegalAddException: The element "note" could not be added as the root of the document: The Content already has an existing parent document
------------------------------

Why will this not work? The problem occurs because I am trying to create two "org.jdom.Document" objects, but this works in pre 1.0 JDOM libraries. Is there is a restriction on the number of Document objects I can create, or have I missed something obvious?

I have tried compiling it and running it on two different systems with two different version of Java, but both give the same result. On Windows XP SP2 I am using:
------------------------------
java version "1.4.2_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
Java HotSpot(TM) Client VM (build 1.4.2_06-b03, mixed mode)
------------------------------

On UNIX, I am using:
------------------------------
java version "1.4.1_03"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_03-b02)
Java HotSpot(TM) Client VM (build 1.4.1_03-b02, mixed mode)
------------------------------

I built the JDOM.JAR library from the latest download available off the website (1.0). As I mentioned, older (pre-1.0 release) JDOM.JAR libraries work OK.

Any help you can offer would be most appreciated.

Best regards,

Rob.