How to send email with attachment using InputStream and Spring?

Question

The situation is like this:

First, we generate a file in the memory, we can get a InputStream object. Second the InputStream object must be send as a attachment of a email. The language is Java, we use Spring to send email.

I have found a lot of information, but I cannot find how to send an email attachment using InputStream. I try to do like this:

InputStreamSource iss= new InputStreamResource(new FileInputStream("c:\\a.txt"));
MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");
message.addAttachment("attachment", iss);

But I get an exception:

Passed-in Resource contains an open stream: invalid argument. JavaMail requires an InputStreamSource that creates a fresh stream for every call.

Answer 1

For files generated in memory, you may use ByteArrayResource. Just convert your InputStream object using IOUtils from the Apache Commons IO library.

It is quite simple:

helper.addAttachment("attachement",
new ByteArrayResource(IOUtils.toByteArray(inputStream)));