Sending mail attachment using Java

I am trying to send an email using Java and Gmail. I have stored my files on the cloud and the stored files I want to send as an attachment to my email.

It should add those files to this mail and not links of those files.

How I can send such attachments?

Working code, I have used Java Mail 1.4.7 jar

import java.util.Properties;
import javax.activation.*;
import javax.mail.*;

public class MailProjectClass {

public static void main(String[] args) {

    final String username = "[email protected]";
    final String password = "your.password";

    Properties props = new Properties();
    props.put("mail.smtp.auth", true);
    props.put("mail.smtp.starttls.enable", true);
    props.put("mail.smtp.host", "smtp.gmail.com");
    props.put("mail.smtp.port", "587");

    Session session = Session.getInstance(props,
            new javax.mail.Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(username, password);
                }
            });

    try {

        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress("[email protected]"));
        message.setRecipients(Message.RecipientType.TO,
                InternetAddress.parse("[email protected]"));
        message.setSubject("Testing Subject");
        message.setText("PFA");

        MimeBodyPart messageBodyPart = new MimeBodyPart();

        Multipart multipart = new MimeMultipart();
        
        String file = "path of file to be attached";
        String fileName = "attachmentName";
        DataSource source = new FileDataSource(file);
        messageBodyPart.setDataHandler(new DataHandler(source));
        messageBodyPart.setFileName(fileName);
        multipart.addBodyPart(messageBodyPart);

        message.setContent(multipart);

        System.out.println("Sending");

        Transport.send(message);

        System.out.println("Done");

    } catch (MessagingException e) {
        e.printStackTrace();
    }
  }
}

For an unknow reason, the accepted answer partially works when I send email to my gmail address. I have the attachement but not the text of the email.

If you want both attachment and text try this based on the accepted answer :

    Properties props = new java.util.Properties();
    props.put("mail.smtp.host", "yourHost");
    props.put("mail.smtp.port", "yourHostPort");
    props.put("mail.smtp.auth", "true");             
    props.put("mail.smtp.starttls.enable", "true");


    // Session session = Session.getDefaultInstance(props, null);
    Session session = Session.getInstance(props,
              new javax.mail.Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("user", "password");
                }
              });


    Message msg = new MimeMessage(session);
    try {
        msg.setFrom(new InternetAddress(mailFrom));
        msg.setRecipient(Message.RecipientType.TO, new InternetAddress(mailTo));
        msg.setSubject("your subject");

        Multipart multipart = new MimeMultipart();

        MimeBodyPart textBodyPart = new MimeBodyPart();
        textBodyPart.setText("your text");

        MimeBodyPart attachmentBodyPart= new MimeBodyPart();
        DataSource source = new FileDataSource(attachementPath); // ex : "C:\\test.pdf"
        attachmentBodyPart.setDataHandler(new DataHandler(source));
        attachmentBodyPart.setFileName(fileName); // ex : "test.pdf"

        multipart.addBodyPart(textBodyPart);  // add the text part
        multipart.addBodyPart(attachmentBodyPart); // add the attachement part

        msg.setContent(multipart);


        Transport.send(msg);
    } catch (MessagingException e) {
        LOGGER.log(Level.SEVERE,"Error while sending email",e);
    }

Update :

If you want to send a mail as an html content formated you have to do

    MimeBodyPart textBodyPart = new MimeBodyPart();
    textBodyPart.setContent(content, "text/html");

So basically setText is for raw text and will be well display on every server email including gmail, setContent is more for an html template and if you content is formatted as html it will maybe also works in gmail