Java/Email/Email Attachment

Get Attachment File Name

import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.Part;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.URLName;
import javax.mail.internet.InternetAddress;
public class MainClass {
  public static void main(String[] args) throws Exception {
    URLName server = new URLName("protocol://username@host/foldername");
    Session session = Session.getDefaultInstance(new Properties(), new MailAuthenticator());
    Folder folder = session.getFolder(server);
    if (folder == null) {
      System.out.println("Folder " + server.getFile() + " not found.");
      System.exit(1);
    }
    folder.open(Folder.READ_ONLY);
    Message[] messages = folder.getMessages();
    for (int i = 0; i < messages.length; i++) {
      System.out.println(messages[i].getSize() + " bytes long.");
      System.out.println(messages[i].getLineCount() + " lines.");
      String disposition = messages[i].getDisposition();
      if (disposition == null){
        ; // do nothing
      }else if (disposition.equals(Part.INLINE)) {
        System.out.println("This part should be displayed inline");
      } else if (disposition.equals(Part.ATTACHMENT)) {
        System.out.println("This part is an attachment");
        String fileName = messages[i].getFileName();
        System.out.println("The file name of this attachment is " + fileName);
      }
      String description = messages[i].getDescription();
      if (description != null) {
        System.out.println("The description of this message is " + description);
      }
    }
    folder.close(false);
  }
}
class MailAuthenticator extends Authenticator {
  public MailAuthenticator() {
  }
  public PasswordAuthentication getPasswordAuthentication() {
    return new PasswordAuthentication("username", "password");
  }
}

How to use the FileDataSource to send a file via mail

/*
 * @(#)sendfile.java  1.11 03/06/19
 *
 * Copyright 1996-2003 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND
 * ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES OR LIABILITIES
 * SUFFERED BY LICENSEE AS A RESULT OF  OR RELATING TO USE, MODIFICATION
 * OR DISTRIBUTION OF THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL
 * SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR
 * FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS
 * BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that Software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.util.*;
import java.io.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
/**
 * sendfile will create a multipart message with the second
 * block of the message being the given file.<p>
 *
 * This demonstrates how to use the FileDataSource to send
 * a file via mail.<p>
 *
 * usage: <code>java sendfile <i>to from smtp file true|false</i></code>
 * where <i>to</i> and <i>from</i> are the destination and
 * origin email addresses, respectively, and <i>smtp</i>
 * is the hostname of the machine that has smtp server
 * running.  <i>file</i> is the file to send. The next parameter
 * either turns on or turns off debugging during sending.
 *
 * @author  Christopher Cotton
 */
public class sendfile {
    public static void main(String[] args) {
  if (args.length != 5) {
      System.out.println("usage: java sendfile <to> <from> <smtp> <file> true|false");
      System.exit(1);
  }
  String to = args[0];
  String from = args[1];
  String host = args[2];
  String filename = args[3];
  boolean debug = Boolean.valueOf(args[4]).booleanValue();
  String msgText1 = "Sending a file.\n";
  String subject = "Sending a file";
  
  // create some properties and get the default Session
  Properties props = System.getProperties();
  props.put("mail.smtp.host", host);
  
  Session session = Session.getInstance(props, null);
  session.setDebug(debug);
  
  try {
      // create a message
      MimeMessage msg = new MimeMessage(session);
      msg.setFrom(new InternetAddress(from));
      InternetAddress[] address = {new InternetAddress(to)};
      msg.setRecipients(Message.RecipientType.TO, address);
      msg.setSubject(subject);
      // create and fill the first message part
      MimeBodyPart mbp1 = new MimeBodyPart();
      mbp1.setText(msgText1);
      // create the second message part
      MimeBodyPart mbp2 = new MimeBodyPart();
            // attach the file to the message
        FileDataSource fds = new FileDataSource(filename);
      mbp2.setDataHandler(new DataHandler(fds));
      mbp2.setFileName(fds.getName());
      // create the Multipart and add its parts to it
      Multipart mp = new MimeMultipart();
      mp.addBodyPart(mbp1);
      mp.addBodyPart(mbp2);
      // add the Multipart to the message
      msg.setContent(mp);
      // set the Date: header
      msg.setSentDate(new Date());
      
      // send the message
      Transport.send(msg);
      
  } catch (MessagingException mex) {
      mex.printStackTrace();
      Exception ex = null;
      if ((ex = mex.getNextException()) != null) {
    ex.printStackTrace();
      }
  }
    }
}