Send a PDF as an attachment through Sendgrid

Question

I'm using Sendgrid to send emails through an app on GAE. It's working fine, but I also want to be able to send PDFs as an attachment. I'm not using Sendgrid.jar file in my project. I've just used Sendgrid.java. And this class has no methods by which i can add attachments. Can someone help me?

Answer 1

public static boolean sendEmail(String fromMail, String title, String toMail, String message) throws IOException {
    Email from = new Email(fromMail);
    String subject = title;
    Email to = new Email(toMail);

    Content content = new Content("text/html", message);
    Mail mail = new Mail(from, subject, to, content);

    Path file = Paths.get("file path");
    Attachments attachments = new Attachments();
    attachments.setFilename(file.getFileName().toString());
    attachments.setType("application/pdf");
    attachments.setDisposition("attachment");

    byte[] attachmentContentBytes = Files.readAllBytes(file);
    String attachmentContent = Base64.getMimeEncoder().encodeToString(attachmentContentBytes);
    String s = Base64.getEncoder().encodeToString(attachmentContentBytes);
    attachments.setContent(s);
    mail.addAttachments(attachments);

    SendGrid sg = new SendGrid("sendgrid api key");
    Request request = new Request();

    request.setMethod(Method.POST);
    request.setEndpoint("mail/send");
    request.setBody(mail.build());
    Response response = sg.api(request);

    if (response != null) {
        return true;
    } else {
        return false;
    }
}

Define above static method and call with relevant arguments as your program wants.

Answer 2

I personally find it easier to directly construct the JSON request body as described in the API docs than to use Sendgrid's libraries. I only use the Sendgrid library for sending the request after I construct the JSON data myself.

When constructing the JSON data you need to specify at least a filename and the content (i.e., the PDF file). Make sure to Base64 encode the PDF file before adding it to the JASON data.

I'd include some code, but I do Python and not Java so not sure that would help.

Answer 3

Here is the code of a servlet that sends a mail with a PDF as attachment, through Sendgrid:

    @Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
    ....

    ByteArrayOutputStream os = null;
    try {
        PDFGenerator pdfGenerator = new PDFGenerator(invoiceOut);
        os = pdfGenerator.getPDFOutputStream();
    } catch (Exception e) {
        ....
    }

    SendGrid sendgrid = new SendGrid(Constants.SENDGRID_API_KEY);
    SendGrid.Email email = new SendGrid.Email();
    email.addTo(....);
    email.setFrom(....);
    email.setFromName(....);
    email.setSubject(....);
    email.setHtml("......");

    ByteBuffer buf = null;
    if (os == null) {
        //error...
    } else {
        buf = ByteBuffer.wrap(os.toByteArray());
    }

    InputStream attachmentDataStream = new ByteArrayInputStream(buf.array());

    try {
        email.addAttachment("xxxxx.pdf", attachmentDataStream);
        SendGrid.Response response = sendgrid.send(email);

    } catch (IOException e) {
        ....
        throw new RuntimeException(e);
    } catch (SendGridException e) {
        ....
        throw new RuntimeException(e);
    }

}

PDFGenerator is one of my classes in which getPDFOutputStream method returns the PDF as ByteArrayOutputStream.