EmailUtil.java

package com.application;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import java.io.UnsupportedEncodingException;
import java.util.Date;

public class EmailUtil {

    /**
     * Utility method to send simple HTML email
     * @param session
     * @param toEmail
     * @param subject
     * @param body
     */
    public static void sendEmail(Session session, String toEmail, String subject, String body){
        try
        {
            MimeMessage msg = new MimeMessage(session);
            //set message headers
            msg.addHeader("Content-type", "text/HTML; charset=UTF-8");
            msg.addHeader("format", "flowed");
            msg.addHeader("Content-Transfer-Encoding", "8bit");

            msg.setFrom(new InternetAddress("no_reply@example.com", "NoReply-JD"));
            msg.setReplyTo(InternetAddress.parse("no_reply@example.com", false));
            msg.setSubject(subject, "UTF-8");
            msg.setText(body, "UTF-8");
            msg.setSentDate(new Date());

            msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail, false));
            System.out.println("Message is ready");
            Transport.send(msg);

            System.out.println("EMail Sent Successfully!!");
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Utility method to send email with attachment
     * @param session
     * @param toEmail
     * @param subject
     * @param body
     */
    public static void sendAttachmentEmail(Session session, String toEmail, String subject, String body){
        try{
            MimeMessage msg = new MimeMessage(session);
            msg.addHeader("Content-type", "text/HTML; charset=UTF-8");
            msg.addHeader("format", "flowed");
            msg.addHeader("Content-Transfer-Encoding", "8bit");

            msg.setFrom(new InternetAddress("no_reply@example.com", "NoReply-JD"));

            msg.setReplyTo(InternetAddress.parse("no_reply@example.com", false));

            msg.setSubject(subject, "UTF-8");

            msg.setSentDate(new Date());

            msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail, false));

            // Create the message body part
            BodyPart messageBodyPart = new MimeBodyPart();

            // Fill the message
            messageBodyPart.setText(body);

            // Create a multipart message for attachment
            Multipart multipart = new MimeMultipart();

            // Set text message part
            multipart.addBodyPart(messageBodyPart);

            // Second part is attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "abc.txt";
            DataSource source = new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            multipart.addBodyPart(messageBodyPart);

            // Send the complete message parts
            msg.setContent(multipart);

            // Send message
            Transport.send(msg);
            System.out.println("EMail Sent Successfully with attachment!!");
        }catch (MessagingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    /**
     * Utility method to send image in email body
     * @param session
     * @param toEmail
     * @param subject
     * @param body
     */
    public static void sendImageEmail(Session session, String toEmail, String subject, String body){
        try{
            MimeMessage msg = new MimeMessage(session);
            msg.addHeader("Content-type", "text/HTML; charset=UTF-8");
            msg.addHeader("format", "flowed");
            msg.addHeader("Content-Transfer-Encoding", "8bit");

            msg.setFrom(new InternetAddress("no_reply@example.com", "NoReply-JD"));

            msg.setReplyTo(InternetAddress.parse("no_reply@example.com", false));

            msg.setSubject(subject, "UTF-8");

            msg.setSentDate(new Date());

            msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail, false));

            // Create the message body part
            BodyPart messageBodyPart = new MimeBodyPart();

            messageBodyPart.setText(body);

            // Create a multipart message for attachment
            Multipart multipart = new MimeMultipart();

            // Set text message part
            multipart.addBodyPart(messageBodyPart);

            // Second part is image attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "image.png";
            DataSource source = new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            //Trick is to add the content-id header here
            messageBodyPart.setHeader("Content-ID", "image_id");
            multipart.addBodyPart(messageBodyPart);

            //third part for displaying image in the email body
            messageBodyPart = new MimeBodyPart();
            messageBodyPart.setContent("<h1>Attached Image</h1>" +
                    "<img src='cid:image_id'>", "text/html");
            multipart.addBodyPart(messageBodyPart);

            //Set the multipart message to the email message
            msg.setContent(multipart);

            // Send message
            Transport.send(msg);
            System.out.println("EMail Sent Successfully with image!!");
        }catch (MessagingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

}