Using DOM Implementation Provided in JDK

XML Tutorials - Herong's Tutorial Examples

∟DOM (Document Object Model) Programming Interface

∟Using DOM Implementation Provided in JDK

This section provides a tutorial example on how to use the DOM interface included in JDK, which actually uses DOM implementation provided in the org.apache.crimson package.

Here is a program to show how different packages are used together to parse an XML file into a DOM document object:

/* DOMParser.java
 - Copyright (c) 2002-2018 HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import org.xml.sax.*;
class DOMParser {
   public static void main(String[] args) {
      try {
         File x = new File(args[0]);
         DocumentBuilderFactory f
            = DocumentBuilderFactory.newInstance();
         System.out.println(f.toString());
         DocumentBuilder b = f.newDocumentBuilder();
         System.out.println(b.toString());
         Document d = b.parse(x);
         System.out.println(d.toString());
         DOMImplementation i = d.getImplementation();
         System.out.println(i.toString());
      } catch (ParserConfigurationException e) {
         System.out.println(e.toString());
      } catch (SAXException e) {
         System.out.println(e.toString());
      } catch (IOException e) {
         System.out.println(e.toString());
      }
   }
}

If you compile and run this sample program with JDK (Java Development Kit), you will get:

herong> java DOMParser hello.xml

com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl...
com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl@106d69c
[#document: null]
com.sun.org.apache.xerces.internal.dom.DeferredDOMImplementationIm...

Note that:

javax.xml.parsers.DocumentBuilderFactory.newInstance() method is used to create a new factory instance using a factory implementation from the com.sun.org.apache.crimson.jaxp.* package.
javax.xml.parsers.DocumentBuilder.newDocumentBuilder() method is used to create a new builder instance using a builder implementation from com.sun.org.apache.crimson.jaxp.* package.
javax.xml.parsers.DocumentBuilder.parse() method is used to parse the XML file into an org.w3c.dom.Document object.
The actual DOM implementation class is com.sun.org.apache.xerces.internal.dom.DeferredDOMImplementationImpl.