how to embed multiple images while sending html email using Java mail

Question

I'm trying to send email from javamail. I'm embeding the images and using CID. But the problem is how do I embed multiple images in a single message. if I try to add in header.. it is just taking the last set header. how do I add multiple images and reference using CID.

MimeMultipart multipart = new MimeMultipart("related");

    // first part  (the html)
    BodyPart messageBodyPart = new MimeBodyPart();
//    BodyPart messageBodyPart = new MimeBodyPart();
    String htmlText = "<H1>Hello</H1><br/> <p align=center><img src=\"cid:senny\"> </p>";
    htmlText+="<p align=center><img src=\"cid:senny\"> </p>";
    htmlText+="<p align=center><img src=\"cid:image\"> </p>";
    messageBodyPart.setContent(htmlText, "text/html");

    // add it
    multipart.addBodyPart(messageBodyPart);

    // second part (the image)
    messageBodyPart = new MimeBodyPart();
    DataSource fds = new FileDataSource
      ("C:\\images\\cec_header_457.png");
    DataSource fds1 = new FileDataSource
    ("C:\\images\\cec_header_420.png");
    messageBodyPart.setDataHandler(new DataHandler(fds));
    messageBodyPart.setDataHandler(new DataHandler(fds1));
    messageBodyPart.addHeader("Content-ID","<image>");
    messageBodyPart.addHeader("Content-ID","<senny>");
    // add it
    multipart.addBodyPart(messageBodyPart);

    // put everything together
    message.setContent(multipart);

Answer 1

Each image needs to be its own MimeBodyPart, break up this code,

// second part (the image)
messageBodyPart = new MimeBodyPart();
DataSource fds = new FileDataSource
  ("C:\\images\\cec_header_457.png");
DataSource fds1 = new FileDataSource
("C:\\images\\cec_header_420.png");
messageBodyPart.setDataHandler(new DataHandler(fds));
messageBodyPart.setDataHandler(new DataHandler(fds1));
messageBodyPart.addHeader("Content-ID","<image>");
messageBodyPart.addHeader("Content-ID","<senny>");
// add it
multipart.addBodyPart(messageBodyPart);

Into two multi parts, something like

// second part (the image)
messageBodyPart = new MimeBodyPart();
DataSource fds1 = new FileDataSource
("C:\\images\\cec_header_420.png");
messageBodyPart.setDataHandler(new DataHandler(fds1));
messageBodyPart.addHeader("Content-ID","<senny>");
// add it
multipart.addBodyPart(messageBodyPart);

messageBodyPart = new MimeBodyPart();
DataSource fds = new FileDataSource
  ("C:\\images\\cec_header_457.png");
messageBodyPart.setDataHandler(new DataHandler(fds));
messageBodyPart.addHeader("Content-ID","<image>");
// add it
multipart.addBodyPart(messageBodyPart);

Answer 2

Yes each image needs its own MimeBodyPart. Above solution is only for two images. In case, if there are multiple images, it is not efficient to create multiple object for MimeBodyPart.

So,Lets go up with function,

public void imgUpload(Multipart multipart,String fileName) throws MessagingException
{
    int no = rand.nextInt();
    String contentId = Integer.toString(no);
    System.out.println(contentId);

    BodyPart messageBodyPart = new MimeBodyPart();
    String htmlText = "<img align=\" center \" src=\"cid:"+contentId+"\"><br>";
    messageBodyPart.setContent(htmlText+"<br>", "text/html");

    // add it
    multipart.addBodyPart(messageBodyPart);
    System.out.println(contentId);

    // second part (the image)
    messageBodyPart = new MimeBodyPart();
    DataSource fds = new FileDataSource(fileName);

    messageBodyPart.setDataHandler(new DataHandler(fds));
    messageBodyPart.setHeader("Content-ID", "<"+contentId+">");
    System.out.println(contentId);

    // add image to the multipart
    multipart.addBodyPart(messageBodyPart);
}

Here parameters to be passed are Object of MimeBodyPart and path of image. Each image needs its own content-id, so content-id is generated randomly for this scenario.

Full code to embed multiple images :

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

public class SendImageEmail
{
   public static void main(String [] args)
   {
      SendImageEmail sendEmail = new SendImageEmail(); 
      sendEmail.SendemailwithImage();
   } 
   public void imgUpload(Multipart multipart,String fileName) throws MessagingException
   {
     int no = rand.nextInt();
     String contentId = Integer.toString(no);
     System.out.println(contentId);

     BodyPart messageBodyPart = new MimeBodyPart();
     String htmlText = "<img align=\" center \" src=\"cid:"+contentId+"\"><br>";
     messageBodyPart.setContent(htmlText+"<br>", "text/html");

     // add it
     multipart.addBodyPart(messageBodyPart);
     System.out.println(contentId);

     // second part (the image)
     messageBodyPart = new MimeBodyPart();
     DataSource fds = new FileDataSource(fileName);

     messageBodyPart.setDataHandler(new DataHandler(fds));
     messageBodyPart.setHeader("Content-ID", "<"+contentId+">");
     System.out.println(contentId);

     // add image to the multipart
     multipart.addBodyPart(messageBodyPart);
   }

  public void SendemailwithImage(){
       SendImageEmail imgEmail = new SendImageEmail(); 
       List<String> imgPath = new ArrayList<String>();
       imgPath.add("D:\\img1.png");
       imgPath.add("D:\\img2.png");
       imgPath.add("D:\\img3.png");

  // Recipient's email ID needs to be mentioned.
  String to = "[email protected]";

  // Sender's email ID needs to be mentioned
  String from = "[email protected]";

  // Assuming you are sending email from localhost
  String host = "localhost";

  // Get system properties
  Properties properties = System.getProperties();

  // Setup mail server
  properties.setProperty("mail.smtp.host", host);

  // Get the default Session object.
  Session session = Session.getDefaultInstance(properties);

  try{
     // Create a default MimeMessage object.
     MimeMessage message = new MimeMessage(session);

     // Set From: header field of the header.
     message.setFrom(new InternetAddress(from));

     // Set To: header field of the header.
     message.addRecipient(Message.RecipientType.TO,
                              new InternetAddress(to));

     // Set Subject: header field
     message.setSubject("This is the Subject Line!");

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

     // Fill the message
     messageBodyPart.setText("This is message body");

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

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

    for(String fileName : imgPath)
     {
       imgEmail.upload(multipart,fileName); 
     }       
     // Send the complete message parts
     message.setContent(multipart );

     // Send message
     Transport.send(message);
     System.out.println("Sent message successfully....");
  }catch (MessagingException mex) {
     mex.printStackTrace();
  }}}