How to HTMLEditorKit's parser with Sax Parser?

Question

How does one do it? I know you need to override getParser method. But the ParserCallback's handleStartTag, handleEndTag etc expect a parameter pos of type int. Needless to say, the pos is undocumented. I have not idea what value to pass. If I pass -1, I get some exceptions. Anyone has a working code snippet which he/she can share?
Thanks a bunch
Narayanan

Answer 1

ParserCallback is like an event listener.
Take for example a MouseListener. You don't invoke the mouseClicked(...) method. You add code to the mouseClicked(...) method to respond to the mouseClicked event.
Same thing with the ParserCallback. You don't invoke the handleStartTag(...) method. As the ParserCallback is parsing an HTML Document it will notify you when it finds a start tag in the Document. It tells you the tag it found and the position of the tag in the Document.
Here is a simple example that just displays all the text in the document:
import java.io.*;
import java.net.*;
import javax.swing.text.html.parser.*;
import javax.swing.text.html.*;
public class ParserCallbackText extends HTMLEditorKit.ParserCallback
     public void handleText(char[] data, int pos)
          System.out.println( data );
     public static void main(String[] args)
          throws Exception
          Reader reader = getReader(args[0]);
          ParserCallbackText parser = new ParserCallbackText();
          new ParserDelegator().parse(reader, parser, true);
     static Reader getReader(String uri)
          throws IOException
          // Retrieve from Internet.
          if (uri.startsWith("http:"))
               URLConnection conn = new URL(uri).openConnection();
               return new InputStreamReader(conn.getInputStream());
          // Retrieve from file.
          else
               return new FileReader(uri);
}