Question

I have an XML file (on the left) and I want to create multiple files (on the right):

<ParentNode>                                  file1:
    <ChildNode>                               <ParentNode>
        <node></node>                             <ChildNode>
    </childNode>                                      <node></node>
    <ChildNode>                                   </childNode>
        <node></node>                         </ParentNode>
    </childNode>                              file2:
    <ChildNode>                               <ParentNode>
        <node></node>                             <ChildNode>
    </childNode>                                      <node></node>
</ParentNode>                                      </childNode>
                                              </ParentNode>

I am trying to take the first child node from the original XML file and add it to a new one but I keep getting errors around replacing nodes.

I want to do something like the following

 DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
 DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
 Document newDocument;

 Node firstChild = document.getFirstChild();
 NodeList childNodes = firstChild.getChildNodes();

 Element parentNode;
 for (int i = 1; i < childNodes.getLength(); i++ ) {
     newDocument = docBuilder.newDocument();
     parentNode = newDocument.createElement("ParentNode");
     newDocument.appendChild(parentNode);
     newDocument.getFirstChild().appendChild(childNodes.item(i));
 }

but I get an error

org.w3c.dom.DOMException: WRONG_DOCUMENT_ERR: A node is used in a different document than the one that created it.

any help pointing in the right direction appreciated!

Answer 1

From Java documentation,

Use cloneNode method.

SUMMARY:

public Node cloneNode(boolean deep)

Returns a duplicate of this node,
i.e., serves as a generic copy
constructor for nodes. The duplicate
node has no parent; ( parentNode is
null.).

Cloning an Element copies all
attributes and their values, including
those generated by the XML processor
to represent defaulted attributes, but
this method does not copy any text it
contains unless it is a deep clone,
since the text is contained in a child
Text node. Cloning an Attribute
directly, as opposed to be cloned as
part of an Element cloning operation,
returns a specified attribute (
specified is true). Cloning any other
type of node simply returns a copy of
this node.

Note that cloning an immutable subtree
results in a mutable copy, but the
children of an EntityReference clone
are readonly . In addition, clones of
unspecified Attr nodes are specified.
And, cloning Document, DocumentType,
Entity, and Notation nodes is
implementation dependent.

EDIT :

import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.transform.*; 
import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamResult;

public class Test{
 static public void main(String[] arg) throws Exception{

 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
 DocumentBuilder builder = factory.newDocumentBuilder();
 Document doc = builder.parse("foo.xml");

 TransformerFactory tranFactory = TransformerFactory.newInstance(); 
 Transformer aTransformer = tranFactory.newTransformer(); 


 NodeList list = doc.getFirstChild().getChildNodes();

 for (int i=0; i<list.getLength(); i++){
    Node element = list.item(i).cloneNode(true);

 if(element.hasChildNodes()){
   Source src = new DOMSource(element); 
   FileOutputStream fs=new FileOutputStream("k" + i + ".xml");
   Result dest = new StreamResult(fs);
   aTransformer.transform(src, dest);
   fs.close();
   }
   }

  }
}