Insert images in email with JavaMail Api

Question

Following code sample found in:

https://www.codejava.net/java-ee/javamail/embedding-images-into-e-mail-with-javamail

The images are attached to the email, but not embedded in the html of the email.

package net.codejava.mail;

import java.io.IOException;
import java.util.Date;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

/**
 * This utility class provides a functionality to send an HTML e-mail message
 * with embedded images.
 * @author www.codejava.net
 *
 */
public class EmbeddedImageEmailUtil {

    /**
     * Sends an HTML e-mail with inline images.
     * @param host SMTP host
     * @param port SMTP port
     * @param userName e-mail address of the sender's account 
     * @param password password of the sender's account
     * @param toAddress e-mail address of the recipient
     * @param subject e-mail subject
     * @param htmlBody e-mail content with HTML tags
     * @param mapInlineImages 
     *          key: Content-ID
     *          value: path of the image file
     * @throws AddressException
     * @throws MessagingException
     */
    public static void send(String host, String port,
            final String userName, final String password, String toAddress,
            String subject, String htmlBody, 
            Map<String, String> mapInlineImages)
                throws AddressException, MessagingException {
        // sets SMTP server properties
        Properties properties = new Properties();
        properties.put("mail.smtp.host", host);
        properties.put("mail.smtp.port", port);
        properties.put("mail.smtp.auth", "true");
        properties.put("mail.smtp.starttls.enable", "true");
        properties.put("mail.user", userName);
        properties.put("mail.password", password);

        // creates a new session with an authenticator
        Authenticator auth = new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(userName, password);
            }
        };
        Session session = Session.getInstance(properties, auth);

        // creates a new e-mail message
        Message msg = new MimeMessage(session);

        msg.setFrom(new InternetAddress(userName));
        InternetAddress[] toAddresses = { new InternetAddress(toAddress) };
        msg.setRecipients(Message.RecipientType.TO, toAddresses);
        msg.setSubject(subject);
        msg.setSentDate(new Date());

        // creates message part
        MimeBodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setContent(htmlBody, "text/html");

        // creates multi-part
        Multipart multipart = new MimeMultipart();
        multipart.addBodyPart(messageBodyPart);

        // adds inline image attachments
        if (mapInlineImages != null && mapInlineImages.size() > 0) {
            Set<String> setImageID = mapInlineImages.keySet();
            
            for (String contentId : setImageID) {
                MimeBodyPart imagePart = new MimeBodyPart();
                imagePart.setHeader("Content-ID", "<" + contentId + ">");
                imagePart.setDisposition(MimeBodyPart.INLINE);
                
                String imageFilePath = mapInlineImages.get(contentId);
                try {
                    imagePart.attachFile(imageFilePath);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }

                multipart.addBodyPart(imagePart);
            }
        }

        msg.setContent(multipart);

        Transport.send(msg);
    }
}

package net.codejava.mail;

import java.util.HashMap;
import java.util.Map;

/**
 * This program tests out the EmbeddedImageEmailUtil utility class.
 * @author www.codejava.net
 *
 */
public class InlineImageEmailTester {

    /**
     * main entry of the program
     */
    public static void main(String[] args) {
        // SMTP info
        String host = "smtp.gmail.com";
        String port = "587";
        String mailFrom = "YOUR_EMAIL";
        String password = "YOUR_PASSWORD";

        // message info
        String mailTo = "YOUR_RECIPIENT";
        String subject = "Test e-mail with inline images";
        StringBuffer body
            = new StringBuffer("<html>This message contains two inline images.<br>");
        body.append("The first image is a chart:<br>");
        body.append("<img src=\"cid:image1\" width=\"30%\" height=\"30%\" /><br>");
        body.append("The second one is a cube:<br>");
        body.append("<img src=\"cid:image2\" width=\"15%\" height=\"15%\" /><br>");
        body.append("End of message.");
        body.append("</html>");

        // inline images
        Map<String, String> inlineImages = new HashMap<String, String>();
        inlineImages.put("image1", "E:/Test/chart.png");
        inlineImages.put("image2", "E:/Test/cube.jpg");

        try {
            EmbeddedImageEmailUtil.send(host, port, mailFrom, password, mailTo,
                subject, body.toString(), inlineImages);
            System.out.println("Email sent.");
        } catch (Exception ex) {
            System.out.println("Could not send email.");
            ex.printStackTrace();
        }
    }
}

Any comments will be very appreciated.

Answer 1

Problem solved.

I have to change:

new MimeMultipart();

to this:

new MimeMultipart("related");