CODEWITHSUNDEEP
javajakarta-mailniojimfs
Steve
Steve

Reputation: 4701

java attach file from virtual filesystem to email

I am using a virtual filesystem and I'd like to attach a file from it to an email. However, the MimeBodyPart object only takes Files, which don't work on a default filesystem like jimfs. See my code below, where I get an UnsupportedOperation exception when I try to convert to file.

public Email attach(Path file){
    MimeBodyPart attachment = new MimeBodyPart()
    attachment.attachFile(file.toFile())
    attachments.add(attachment)
    return this
}

Upvotes: 1

Views: 403

Answers (2)

Bill Shannon
Bill Shannon

Reputation: 29971

Since jimfs files aren't really files, you can't use the File APIs.

A simple workaround is to use ByteArrayDataSource, which will copy the data.

A better approach would be to write your own PathDataSource that's similar to FileDataSource but uses Files.newInputStream instead of FileInputStream. Then attach the file using:

MimeBodyPart mbp = new MimeBodyPart();
mbp.setDataHandler(new DataHandler(new PathDataSource(path)));
mbp.setFileName(path.getFileName().toString());
mbp.setDisposition(Part.ATTACHMENT);

Upvotes: 3

ColinD
ColinD

Reputation: 110094

Whatever this MimeBodyPart API is really ought to have an option to use a Path so that you could just use the Jimfs file directly, but since the java.nio.file APIs require Java 7 and don't work on Android yet many libraries unfortunately don't support Path yet.

toFile() can never work for a Jimfs file, or for any file that isn't on the default file system, because the File class can only represent files on the default file system. So yeah, you'd need to copy the Jimfs file to the real file system to use this attachFile method.

If the MimeBodyPart API had an option for using a URL or URI for the attachment, you would probably be able to use that plus file.toUri()[.toURL()]. Or if it could use, say, an InputStream you could obviously get one of those from the file and use it instead.

Upvotes: 1

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