How to attach multiple files to an email using JavaMail?

The following Java code is used to attach a file to an email. I want to send multiple files attachments through email. Any suggestions would be appreciated.

public class SendMail {

    public SendMail() throws MessagingException {
        String host = "smtp.gmail.com";
        String Password = "mnmnn";
        String from = "[email protected]";
        String toAddress = "[email protected]";
        String filename = "C:/Users/hp/Desktop/Write.txt";
        // Get system properties
        Properties props = System.getProperties();
        props.put("mail.smtp.host", host);
        props.put("mail.smtps.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        Session session = Session.getInstance(props, null);

        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(from));
        message.setRecipients(Message.RecipientType.TO, toAddress);
        message.setSubject("JavaMail Attachment");
        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText("Here's the file");
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(messageBodyPart);
        messageBodyPart = new MimeBodyPart();
        DataSource source = new FileDataSource(filename);
        messageBodyPart.setDataHandler(new DataHandler(source));
        messageBodyPart.setFileName(filename);
        multipart.addBodyPart(messageBodyPart);
        message.setContent(multipart);

        try {
            Transport tr = session.getTransport("smtps");
            tr.connect(host, from, Password);
            tr.sendMessage(message, message.getAllRecipients());
            System.out.println("Mail Sent Successfully");
            tr.close();
        } catch (SendFailedException sfe) {
            System.out.println(sfe);
        }
    }
}` 

Well, it's been a while since I've done JavaMail work, but it looks like you could just repeat this code multiple times:

DataSource source = new FileDataSource(filename);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(filename);
multipart.addBodyPart(messageBodyPart);

For example, you could write a method to do it:

private static void addAttachment(Multipart multipart, String filename)
{
    DataSource source = new FileDataSource(filename);
    BodyPart messageBodyPart = new MimeBodyPart();        
    messageBodyPart.setDataHandler(new DataHandler(source));
    messageBodyPart.setFileName(filename);
    multipart.addBodyPart(messageBodyPart);
}

Then from your main code, just call:

addAttachment(multipart, "file1.txt");
addAttachment(multipart, "file2.txt");

etc

UPDATE (March 2020)

With the latest JavaMail™ API (version 1.6 at the moment, JSR 919), things are much simpler:

• void attachFile(File file)
• void attachFile(File file, String contentType, String encoding)
• void attachFile(String file)
• void attachFile(String file, String contentType, String encoding)

Useful reading

Here is a nice and to the point tutorial with the complete example:

• JavaMail - How to send e-mail with attachments

    Multipart mp = new MimeMultipart();

        MimeBodyPart mbp1 = new MimeBodyPart();
        mbp1.setContent(body,"text/html");
        mp.addBodyPart(mbp1);

        if(filename!=null)
        {
            MimeBodyPart mbp2 = null;
            FileDataSource fds =null;
            for(int counter=0;counter<filename.length;counter++)
            {
                mbp2 = null;
                fds =null;
                mbp2=new MimeBodyPart();
                fds = new FileDataSource(filename[counter]);
                mbp2.setDataHandler(new DataHandler(fds));
                mbp2.setFileName(fds.getName());
                mp.addBodyPart(mbp2);
            }
        }
        msg.setContent(mp);
        msg.setSentDate(new Date());
        Transport.send(msg);