Java.lang.NullPointerException no protocol: database.xml

Question

* In Order To Handle XML Operations
package edu.yeditepe.cse.util;
import java.util.*;
import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
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.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
* @author xx
public class XMLHandler {
     public final static String ATTRIBUTE           = "value";
     public final static String DOCTYPE_PUBLIC   = "databases";
     public final static String DOCTYPE_SYSTEM   = "database.dtd";
     public final static String ParentElement    = "variable";
     public final static String databaseName          = "databasename";
     public final static String urlName            = "urlname";
     public final static String userName           = "username";
     public final static String passWord           = "password";
     public XMLHandler()
     //     This Function returns the XML File .
     private static Document getDocument(){
                try {             
                 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                 factory.setIgnoringComments(true);
                 factory.setIgnoringElementContentWhitespace(true);
                 factory.setValidating(true);
                 DocumentBuilder builder = factory.newDocumentBuilder();
                  builder.setErrorHandler(new MyErrorHandler());
                 return builder.parse(new InputSource("database.xml"));
             } catch (Exception e) {
                 System.out.println(e.getMessage());
          return null;
     //Adds new Element to The database.Xml File.
     public boolean addElement(String databasename , String urlname, String username , String password ){
          Document doc = getDocument();
          Element root = doc.getDocumentElement();
          Element parentElement = (Element)doc.createElement(ParentElement);//Take parent Element. We have to take this parent Element since we will add new Element to this Parent Element.
          Element databaseNameElement = (Element)doc.createElement(databaseName);//Create Name Element To Bind Value of New Element.
          databaseNameElement.setAttribute(ATTRIBUTE , databasename );//set the attribute of this child.
          Element urlnameElement = (Element)doc.createElement(urlName);//Create Name Element To Bind Value of New Element.
          urlnameElement.setAttribute(ATTRIBUTE , urlname );//set the attribute of this child.
          Element usernameElement = (Element)doc.createElement(userName);//Create Value Element To Bind Value of the new Element.
          usernameElement.setAttribute(ATTRIBUTE , username );//set the attribute of this second child.
          Element passwordElement = (Element)doc.createElement(passWord);//Create Value Element To Bind Value of the new Element.
          passwordElement.setAttribute(ATTRIBUTE , password );//set the attribute of this second child.
          //Form New Variable  via appending its name and value child to itself.
          parentElement.appendChild(databaseNameElement);
          parentElement.appendChild(urlnameElement);
          parentElement.appendChild(usernameElement);
          parentElement.appendChild(passwordElement);
          //Add This Variable To The Root Element.
          root.appendChild(parentElement);
          try{          
               saveDocument(doc);//Save And Close The XML File. Catch any Exception Occured.
               return true;
          }catch(Exception e){
               System.out.println("##error: " + e);     
               e.printStackTrace();
               return false;
     }//add Element Function.
     //     Save changes of the Document doc.
     private boolean saveDocument(Document doc){
          try{
            Transformer xformer = TransformerFactory.newInstance().newTransformer();
          xformer.setOutputProperty(OutputKeys.INDENT, "yes");//For INDENTED PRINTING OF THE FILE
          xformer.setOutputProperty(OutputKeys.ENCODING, "ISO-8859-9");//Determining Encoding Type.
          xformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, DOCTYPE_PUBLIC);//PRESERVE ROOT ELEMENT
          xformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, DOCTYPE_SYSTEM);//REFERENCE TO DTD FILE
          Source source = new DOMSource(doc);
          Result result = new StreamResult(new File("database.xml"));
          xformer.transform(source, result);
            return true;
          }catch(TransformerConfigurationException e){
               System.out.println(e);
          }catch(TransformerException e){
               System.out.println(e);
          return false;
     }//Save
package edu.yeditepe.cse.util;
* @author xx
public class Deneme {
      * @param args
     public static void main(String[] args) {
          // TODO Auto-generated method stub
          XMLHandler xh = new XMLHandler();     
          System.out.println(xh.addElement("dasd","asda","adadad","das"));
}it gives error in linse "Element root = doc.getDocumentElement();"
i am using jre 1.5.0_ 09
xalan-2.7.0.jar
Error on the console is :
no protocol: database.xml
Exception in thread "main" java.lang.NullPointerException
     at edu.yeditepe.cse.util.XMLHandler.addElement(XMLHandler.java:69)
     at edu.yeditepe.cse.util.Deneme.main(Deneme.java:16)
Problem is related with
return builder.parse(new InputSource("database.xml"));
when i am trying to type file:///database.xml instead of database.xml
it adds some more path therefore it doesn't work
Any help appreciated..

Answer 1

It seems that the file you are trying to parse is not in your current working directory. The solution, if that is the problem, would be to specify the full path of the file.