JAVA Mapping DOM Parser Error

Hi Experts,

I am new to Java mapping. My requirement is

Input.xml : -

<?xml version="1.0" encoding="UTF-8" ?>

<ns0:DT_OPERATIONSSOURCE xmlns:ns0="urn:java_mapping2">

<OPERATIONSSOURCE>

      <NUMBER1>1</NUMBER1>

      <NUMBER2>2</NUMBER2>

</OPERATIONSSOURCE>

</ns0:DT_OPERATIONSSOURCE>

Output.xml:-

<?xml version="1.0" encoding="UTF-8" ?>

<ns0:DT_OPERATIONSTARGET xmlns:ns0="urn:java_mapping2">

<OPERATIONSTARGET>

      <ADD>2</ADD>

      <MUL>2</MUL>

</OPERATIONSTARGET>

</ns0:DT_OPERATIONSTARGET>

I am unable to get the output. I am getting the following error.

org.w3c.dom.DOMException: HIERARCHY_REQUEST_ERR: An attempt was made to insert a node where it is not permitted.

  at com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.insertBefore(Unknown Source)

  at com.sun.org.apache.xerces.internal.dom.NodeImpl.appendChild(Unknown Source)

  at giridhar_subPackage.DOMParser111.execute(DOMParser111.java:77)

  at giridhar_subPackage.DOMParser111.main(DOMParser111.java:101)

Please suggest me how i can resolvoe this error. Please find my Java File below:

package svs_subPackage;

import java.io.FileInputStream; 

import java.io.FileOutputStream; 

import java.io.InputStream; 

import java.io.OutputStream; 

import javax.xml.parsers.DocumentBuilder; 

import javax.xml.parsers.DocumentBuilderFactory; 

import javax.xml.transform.Transformer; 

import javax.xml.transform.TransformerFactory; 

import javax.xml.transform.dom.DOMSource; 

import javax.xml.transform.stream.StreamResult; 

import org.w3c.dom.Document; 

import org.w3c.dom.Element; 

import org.w3c.dom.Node; 

import com.sap.aii.mapping.api.AbstractTransformation; 

import com.sap.aii.mapping.api.TransformationInput; 

import com.sap.aii.mapping.api.TransformationOutput; 

import com.sap.aii.mapping.api.StreamTransformationException; 

public class DOMParser111  extends AbstractTransformation { 

  public void execute(InputStream in, OutputStream out) 

    throws StreamTransformationException { 

   try 

   { 

    DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance(); 

    DocumentBuilder builderel=factory.newDocumentBuilder(); 

    /*input document in form of XML*/ 

    Document docIn=builderel.parse(in); 

    /*document after parsing*/ 

    Document docOut=builderel.newDocument(); 

    TransformerFactory tf=TransformerFactory.newInstance(); 

    Transformer transform=tf.newTransformer(); 

  Element root,child,child1,child2; 

  Node textChild,textChild1; 

  Node no1,no2,no3,no4; 

  String no1s="",no2s="",no3s="",no4s="";

  int no1i,no2i,no3i,no4i;

  root=docOut.createElement("ns0:DT_OPERATIONSTARGET"); 

  root.setAttribute("xmlns:ns0","urn:java_mapping2"); 

  child2=docOut.createElement("ADD");

  root.appendChild(child2);

  no1=docIn.getElementsByTagName("NUMBER1").item(0); 

  no2=docIn.getElementsByTagName("NUMBER2").item(0);

  no1i=(Integer.parseInt(no1.getTextContent()))+(Integer.parseInt(no2.getTextContent()));

  no1s=Integer.toString(no1i);

  textChild=docOut.createTextNode(no1s); 

  child2.appendChild(textChild); 

  docOut.appendChild(root); 

  //root.appendChild(child1);

  root.appendChild(child2);

  child1=docOut.createElement("MUL"); 

  root.appendChild(child1);

  no3=docIn.getElementsByTagName("NUMBER1").item(0); 

  no4=docIn.getElementsByTagName("NUMBER2").item(0);

  no2i=(Integer.parseInt(no3.getTextContent()))*(Integer.parseInt(no4.getTextContent()));

  no2s=Integer.toString(no2i);

  textChild1=docOut.createTextNode(no2s); 

  child1.appendChild(textChild1); 

  docOut.appendChild(root); 

  root.appendChild(child1);

    transform.transform(new DOMSource(docOut), new StreamResult(out)); 

   } 

   catch(Exception e) 

   { 

    e.printStackTrace(); 

   } 

  } 

  public static void main(String[] args) { 

   try{ 

  DOMParser111 genFormat=new DOMParser111(); 

    FileInputStream in=new FileInputStream("C:\\Users\\pc\\Desktop\\SrcFolder\\input111.xml"); 

    FileOutputStream out=new FileOutputStream("C:\\Users\\pc\\Desktop\\RcvFolder\\output111.xml"); 

    genFormat.execute(in,out); 

   } 

   catch(Exception e) 

   { 

    e.printStackTrace(); 

   } 

  }

public void transform(TransformationInput arg0, TransformationOutput arg1) 

   throws StreamTransformationException { 

  // TODO Auto-generated method stub 

  this.execute(arg0.getInputPayload().getInputStream(), arg1.getOutputPayload().getOutputStream()); 

} 

} 

Regards,

GIRIDHAR