How to send email with attachment using InputStream and Spring?

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.

You can make simple implementation of InputStreamSource and pass fresh InputStream in it, as requested:

InputStreamSource iss = new InputStreamSource() {
@Override
public InputStream getInputStream() throws IOException {
// provide fresh InputStream
return new FileInputStream("c:\\a.txt");
}
}
MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");
message.addAttachment("attachment", iss);

//inlineFileObjectCreated -- you can create a StringBuilder Object for a example

ByteArrayDataSource source = new ByteArrayDataSource("file name", "contentType", inlineFileObjectCreated.getBytes() );

JavaMailSender mailSender = (JavaMailSender) ServicesHome.getService("javaMailSender");
MimeMessage mimeMessage = mailSender.createMimeMessage();
MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage, true);
mimeMessageHelper.setTo(toArray);
mimeMessageHelper.setSubject("");
mimeMessageHelper.setText("");
mimeMessageHelper.addAttachment("filename", source);
mailSender.send(mimeMessageHelper.getMimeMessage());

/////////////////////////////////////////////


import javax.activation.DataSource;

public class ByteArrayDataSource implements DataSource {
byte[] bytes;
String contentType;
String name;

public ByteArrayDataSource( String name, String contentType, byte[] bytes ) {
this.name = name;
this.bytes = bytes;
this.contentType = contentType;
}

public String getContentType() {
return contentType;
}

public InputStream getInputStream() {
return new ByteArrayInputStream(bytes);
}

public String getName() {
return name;
}

public OutputStream getOutputStream() throws IOException {
throw new FileNotFoundException();
}
}

The working examples are:

1) Attachment is an `InputStreamSource` interface

public void send() throws IOException, MessagingException {
final ByteArrayOutputStream stream = createInMemoryDocument("body");
final InputStreamSource attachment = new ByteArrayResource(stream.toByteArray());
final MimeMessage message = javaMailSender.createMimeMessage();
final MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setSubject("subject");
helper.setFrom("[email protected]");
helper.setTo("[email protected]");
helper.setReplyTo("[email protected]");
helper.setText("stub", false);
helper.addAttachment("document.txt", attachment);
javaMailSender.send(message);
}

2) Attachment is an `DataSource` interface

public void send() throws IOException, MessagingException {
final ByteArrayOutputStream document = createInMemoryDocument("body");
final InputStream inputStream = new ByteArrayInputStream(document.toByteArray());
final DataSource attachment = new ByteArrayDataSource(inputStream, "application/octet-stream");
final MimeMessage message = javaMailSender.createMimeMessage();
final MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setSubject("subject");
helper.setFrom("[email protected]");
helper.setTo("[email protected]");
helper.setReplyTo("[email protected]");
helper.setText("stub", false);
helper.addAttachment("document.txt", attachment);
javaMailSender.send(message);
}

**The explanation:**

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

This message could appear if the developer use an implementation of `InputStreamSource` that return `true` in the `isOpen()` method.

There is a special check in the method `MimeMessageHelper#addAttacment()`:

public void addAttachment(String attachmentFilename, InputStreamSource inputStreamSource, String contentType) {
//...
if (inputStreamSource instanceof Resource && ((Resource) inputStreamSource).isOpen()) {
throw new IllegalArgumentException(
"Passed-in Resource contains an open stream: invalid argument. " +
"JavaMail requires an InputStreamSource that creates a fresh stream for every call.");
}
//...
}

`InputStreamResource#isOpen()` always return `true` that makes impossible to use this implementation as an attachment:

public class InputStreamResource extends AbstractResource {
//...
@Override
public boolean isOpen() {
return true;
}
//...
}

For files generated *in memory*, you may use `ByteArrayResource`. Just convert your `InputStream` object using [`IOUtils`][1] from the [*Apache Commons IO*][2] library.

It is quite simple:

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


[1]:

[To see links please register here]

[2]:

[To see links please register here]

Have a look at the spring reference chapter [24.3 Using the JavaMail MimeMessageHelper][1]

The example is from there, I think it do want you want to do:

JavaMailSenderImpl sender = new JavaMailSenderImpl();
sender.setHost("mail.host.com");

MimeMessage message = sender.createMimeMessage();

// use the true flag to indicate you need a multipart message
MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setTo("[email protected]");

helper.setText("Check out this image!");

// let's attach the infamous windows Sample file (this time copied to c:/)
FileSystemResource resource = new FileSystemResource(new File("c:/Sample.jpg"));

helper.addAttachment("CoolImage.jpg", resource );

sender.send(message);

if you want to use a Stream, then you can use

ByteArrayResource resource = new ByteArrayResource(IOUtils.toByteArray(inputStream)));

instead of FileSystemResource


[1]:

[To see links please register here]