Javax.mail or java email - how to open email without direct sending

Question

I'm trying to figure it out of how to open an email using javax.mail. My goal is to provide a feature where a user clicks on a button and a default email will open with an attachment. So far, I'm using javax.mail and what it does is just sending the email right when the button is click. Is there a way to just open the email without direct sending? If so, how? I'm using Java 8.

I can't use the 'mailto:' because I need to attach a png file when a user opens an email. Also I'm not sure if I should use ProcessBuilder to open outlook because every user's machine will have a different userName within the C Drive or I'm not sure how to use that.

Here's my code just in case if you need it

 String result;
       String to = "....gov";
       String from = "....gov";
       String host = "....gov";

       Properties properties = System.getProperties();
       properties.setProperty("mail.smtp.host", host);
       Session mailSession = Session.getDefaultInstance(properties);
           try{
          MimeMessage message = new MimeMessage(mailSession);
          message.setFrom(new InternetAddress(emailFrom));
         message.addRecipient(Message.RecipientType.TO,new InternetAddress(emailTo));
          message.setSubject("meh!");

          BodyPart messageBodyPart = new MimeBodyPart();
          messageBodyPart.setText("text body mehmehmehmeh");

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

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

             // Part two is attachment
             messageBodyPart = new MimeBodyPart();
             String filename = "testing.png";
             DataSource source = new FileDataSource(filename);
             String imageString = toDataURL.substring("data:image/png;base64," .length());
             byte[] contentdata = imageString.getBytes();
             ByteArrayDataSource ds = new ByteArrayDataSource(contentdata, "image/png");

             messageBodyPart.setDataHandler(new DataHandler(ds));
             messageBodyPart.setFileName(filename);
             multipart.addBodyPart(messageBodyPart);  //

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

          Transport.send(message);
          result = "Sent message successfully....";
       }catch (MessagingException mex) {
          mex.printStackTrace();
          result = "Error: unable to send message....";
       }

score 1 · Answer 1 · answered May 15 '18 at 14:14

Is there a way to just open the email without direct sending? If so, how?

Don't call Transport.send. Then follow the steps in this answer. and start with msg.saveChanges(). There is an X-Unsent header in that answer that can be used to toggle some outlook features.

Also I'm not sure if I should use ProcessBuilder to open outlook because every user's machine will have a different userName within the C Drive or I'm not sure how to use that.

You use File.createTempFile as this will account for user names. If you need to save in a different location you can read from System.getProperty or if you are only targeting Windows machines you can read from System.getenv. To list all the environment vars you can type set in the command window.

Javax.mail or java email - how to open email without direct sending

1 Answers1