Managing ezines with JavaMail and XSLT, Part 2

package com.psol.xslist;

import java.io.*;
import java.util.*;
import javax.mail.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;
import javax.mail.internet.*;
import javax.xml.transform.*;
import javax.xml.transform.sax.*;
import javax.xml.transform.stream.*;

public class ConfigHandler
   extends DefaultHandler
{
   protected static final String
      NAMESPACE_URI = "http://www.psol.com/xns/xslist/config";
   protected static final int NONE = 0,
                              EMAIL = 1,
                              HEADER = 2,
                              BODY = 3,
                              PART = 4;
   protected int state;
   protected File source;
   protected Multipart multipart;
   protected Message message;

   public void startElement(String uri,
                            String name,
                            String qualifiedName,
                            Attributes atts)
      throws SAXException
   {
      try
      {
         if(!uri.equals(NAMESPACE_URI))
            return;
         if(state == BODY &&
            (name.equals("part") || name.equals("text")))
         {
            state = PART;
            String styleSheet = atts.getValue("styleSheet"),
                   contentType = atts.getValue("contentType");
            BodyPart part = createBodyPart(source,
                                           new File(styleSheet),
                                           contentType,
                                           name.equals("text"));
            multipart.addBodyPart(part);
         }
         else if(state == EMAIL && name.equals("body"))
         {
            state = BODY;
            multipart = new MimeMultipart("alternative");
            source = new File(atts.getValue("source"));
         }
         else if(state == EMAIL && name.equals("header"))
         {
            state = HEADER;
            InternetAddress from =
                new InternetAddress(atts.getValue("from"));
            InternetAddress to[] =
               InternetAddress.parse(atts.getValue("to"));
            message.setFrom(from);
            message.setRecipients(Message.RecipientType.TO,to);
            message.setSubject(atts.getValue("subject"));
            message.setSentDate(new Date());
         }
         else if(state == NONE && name.equals("email"))
         {
            state = EMAIL;
            Properties props = System.getProperties();
            props.put("mail.smtp.host",atts.getValue("smtp"));
            Session session = Session.getDefaultInstance(props);
            message = new MimeMessage(session);
         }
      }
      catch(MessagingException e)
      {
         throw new SAXException("Messaging exception",e);
      }
      catch(TransformerException e)
      {
         throw new SAXException("Transformer exception",e);
      }
   }

   public void endElement(String uri,
                          String name,
                          String qualifiedName)
      throws SAXException
   {
      try
      {
         if(!uri.equals(NAMESPACE_URI))
            return;
         if(state == PART &&
            (name.equals("part") || name.equals("text")))
         {
            state = BODY;
         }
         else if(state == BODY && name.equals("body"))
         {
            state = EMAIL;
            message.setContent(multipart);
         }
         else if(state == HEADER && name.equals("header"))
         {
            state = EMAIL;
         }
         else if(state == EMAIL && name.equals("email"))
         {
            state = NONE;
            Transport.send(message);
         }
      }
      catch(MessagingException e)
      {
         throw new SAXException("Messaging exception",e);
      }
   }

   public void startDocument()
   {
      state = NONE;
      source = null;
      multipart = null;
      message = null;
   }

   protected BodyPart createBodyPart(File source,
                                     File styleSheet,
                                     String contentType,
                                     boolean toText)
      throws MessagingException, TransformerException
   {
      TransformerFactory factory =
         TransformerFactory.newInstance();
      Transformer transformer =
         factory.newTransformer(new StreamSource(styleSheet));
      StringWriter stringWriter = new StringWriter();
      PrintWriter printWriter = new PrintWriter(stringWriter);
      if(toText)
      {
         Xml2Text xml2Text = new Xml2Text(printWriter);
         WhitespaceFilter spaceFilter = new WhitespaceFilter();
         spaceFilter.setContentHandler(xml2Text);
         AsciiFilter asciiFilter = new AsciiFilter();
         asciiFilter.setContentHandler(spaceFilter);
         transformer.transform(new StreamSource(source),
                               new SAXResult(asciiFilter));
         printWriter.close();
         String st = stringWriter.toString();
         BodyPart part = new MimeBodyPart();
         part.setText(st);
         return part;
      }
      else
      {
         transformer.transform(new StreamSource(source),
                               new StreamResult(stringWriter));
         printWriter.close();
         String st = stringWriter.toString();
         MimeBodyPart part = new MimeBodyPart();
         part.setContent(st,"text/html");
         return part;
      }
   }
}