Xalan: The org.apache.xalan.xsltc.trax.DOM2SAX Class

Extends: java.lang.Object

Implements: org.xml.sax.XMLReader, org.xml.sax.Locator

Members

Overview

The main purpose of this class is to provide bridge from DOM to SAX. This can be guessed from the name of this class. Most of the methods in this class are used internally. However, I have given examples of those methods useful to the User. This class implements org.xmlsax.XMLReader so by default it allows an application to set and query features and properties in the parser, to register event handlers for document processing, and to initiate a document parse.

Method Overviews

As I have mentioned earlier, methods in this class are used internally. Also I have mentioned that this class provides a bridge from DOM to SAX. Sometimes during programming, we need to parser a org.w3c.dom.Document using SAX parser so that we can implement business logic. But this does not occur always. Generally we use Inputsource, File or URIs for parsing in SAX parser. But we occasionally parse org.w3c.dom.Document using SAX Parser. This class provides methods to parser a org.w3c.dom.Document, set  setContentHandler for event handling,  setEntityResolver for associating an EntityResolver, setErrorHandler for associating an ErrorHandler and , setDTDHandler for handling DTD related handlers.

Example of creating an instance of DOM2SAX:

/**

     * This method gives example of how to use DOM2SAX for parsing a org.w3c.dom.Document

     * and associating  a ContentHandler.

     * @param uri String

     */

    public void dom2saxUsingInputSource(String uri){

        try{

            System.out.println("Starting parsing URI :"+uri);

            Document doc = DocumentBuilderAdapter.getDocumentBuilder().parse(uri);

            DOM2SAX dom2SAX = new DOM2SAX(doc);

            dom2SAX.setContentHandler(new ContentHandlerImpl());

            dom2SAX.parse();

        }catch(Exception e){

            e.printStackTrace();

        }

    }

Example of parse ():

This method is used to parse a org.w3c.dom.Document, which is passed as an argument for creating instance of DOM2SAX instance.         

 DOM2SAX dom2SAX = new DOM2SAX(doc);

            dom2SAX.setContentHandler(new ContentHandlerImpl());

            dom2SAX.parse();

Example of ContentHandler(ContentHandler):

This method is used to associate a ContentHandler to the SAX parser.

            dom2SAX.setContentHandler(new ContentHandlerImpl()); // ContentHandlerImpl class implements ContentHandler.

Note: Please see the attached source code for more implementation.