EmailService.java

package adt.mainnode.service;

import org.springframework.stereotype.Service;
import org.springframework.beans.factory.annotation.Autowired;

import com.sun.mail.smtp.SMTPTransport;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Date;
import java.util.Properties;


// FOR ATTACHMENTS
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;


@Service
public class EmailService {

    private static final String SMTP_SERVER = "smtp.gmail.com";
    private static final String USERNAME = "adt.event.notifier@gmail.com";
    private static final String PASSWORD = "adtctb2020";

    private static final String EMAIL_FROM = "adt.event.notifier@gmail.com";
    private static final String EMAIL_TO = "alb.blazquez.h@gmail.com, alberto.bherranz@upm.es";
    private static final String EMAIL_TO_CC = "";

    private static final String EMAIL_SUBJECT = "Test Send Email via SMTP";
    private static final String EMAIL_TEXT = "Hello Java Mail \n ABC123";

    @Autowired
    public EmailService() {

    }


    public static void sendEmail(String destination) {

        Properties prop = System.getProperties();
        prop.put("mail.smtp.host", SMTP_SERVER); //optional, defined in SMTPTransport
        prop.put("mail.smtp.auth", "true");
        prop.put("mail.smtp.starttls.enable", "true");
        prop.put("mail.smtp.port", "25"); // default port 25

        Session session = Session.getInstance(prop, null);
        Message msg = new MimeMessage(session);

        try {

            // from
            msg.setFrom(new InternetAddress(EMAIL_FROM));

            // to
            msg.setRecipients(Message.RecipientType.TO,
                    InternetAddress.parse(EMAIL_TO, false));

            // cc
            msg.setRecipients(Message.RecipientType.CC,
                    InternetAddress.parse(EMAIL_TO_CC, false));

            // subject
            msg.setSubject(EMAIL_SUBJECT);

            /* //Attachment part1
            MimeBodyPart p1 = new MimeBodyPart();
            p1.setText(EMAIL_TEXT);
            */

            // content
            msg.setText(EMAIL_TEXT);

            msg.setSentDate(new Date());

            /* //Attachment part 2
            MimeBodyPart p2 = new MimeBodyPart();
            FileDataSource fds = new FileDataSource("path/example.txt");
            p2.setDataHandler(new DataHandler(fds));
            p2.setFileName(fds.getName());

            Multipart mp = new MimeMultipart();
            mp.addBodyPart(p1);
            mp.addBodyPart(p2);

            msg.setContent(mp);
            */

            // Get SMTPTransport
            SMTPTransport t = (SMTPTransport) session.getTransport("smtp");

            // connect
            t.connect(SMTP_SERVER, USERNAME, PASSWORD);

            // send
            t.sendMessage(msg, msg.getAllRecipients());

            System.out.println("Response: " + t.getLastServerResponse());

            t.close();

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

    }

}