Send a mail with attachment in java - jakarta-mail

Question

I want to send mail with attachment in java with the following criteria -
The file which I want to attach is a downloadable URL
(like : http://berkeleycollege.edu/browser_check/samples/excel.xls)
Code is deployed on appengine, so Write to File, Create File, Save File is prohibited by google.
I don't even have the permission to download the file first and attach it as an attachment.
I have tried InputStream input = new URL(url).openStream(); to read the file content pass that to a datahandler. Where url is mentioned above. Sample Code:
Message msg = new MimeMessage(session);
Multipart multiPart = new MimeMultipart();
MimeBodyPart attachment = new MimeBodyPart();
DataHandler handler;
InputStream input = new URL(url).openStream();
handler = new DataHandler(new ByteArrayDataSource(input,"xls");
attachment.setDataHandler(handler);
multiPart.addBodyPart(attachment);
msg.setContent(multiPart);
Transport.send(msg);
Above code is giving Invalid Content error.
Is there anyway, I can read the content of that downloadable link and that content can be send as attachment ?
Please share the code snippet for the reference.

Answer 1

Map model = new HashMap();
String text = null;
Properties properties_mail = new Properties();
InputStream iStream_mail = null;
String propFileName_mail = "properties/mail.properties";
InputStream stream_mail = getClass().getClassLoader().getResourceAsStream(propFileName_mail);
properties_mail.load(stream_mail);
MimeMessage message = this.javamailsenderImpl.createMimeMessage();
MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(message, MimeMessageHelper.MULTIPART_MODE_RELATED, "UTF-8");
mimeMessageHelper.setFrom(properties_mail.getProperty("javaMailSender.username"));
mimeMessageHelper.setTo(user.getUserEmail());
mimeMessageHelper.setSubject("Bpa Qa Product - New Organisation User");
/*String mailBody = "Welcome New User!!! <br /> Your Login Id is : "+user.getUserEmail()+"Your Password is:"+user.getUserPassword();
mimeMessageHelper.setText(mailBody, true);*/
model.put("firstName", user.getFirstName());
model.put("userEmail", user.getUserEmail());
model.put("userPassword", user.getUserPassword());
model.put("organizationName", user.getOrganization().getOrganizationName());
model.put("heading", "Thank You for Registering with us .!! Here is your Login credentials.");
text = VelocityEngineUtils.mergeTemplateIntoString(velocityEngine, "UserDetails.vm", "UTF-8", model);
mimeMessageHelper.setText(new String(text.getBytes(), "UTF-8"), true);
this.javamailsenderImpl.send(message);