Question

i used javamail api to send emails with attachments from java applications, and it is just simple.

File f= new File(file);
MimeBodyPart mbp2 = new MimeBodyPart();

try {
    mbp2.attachFile(f);
} catch (IOException e) {
    e.printStackTrace();
}



Multipart mp= new MimeMultipart();
mp.addBodyPart(mbp2);

message.setContent(mp);

but the thing i want is to know is how to know the uploading progress of my attachment, unlike httpclient i can’t find an outputstream to writeto!
thanks!

Answer 1

See the method implementation.

public void attachFile(File file) throws IOException, MessagingException {
    FileDataSource fds = new FileDataSource(file);      
    this.setDataHandler(new DataHandler(fds));
    this.setFileName(fds.getName());
}

You need to override FileDataSource with your custom implementation that tracks file upload.

You should override getInputStream() method to return a FilterOutputStream that count the read bytes. Apache commons-io has CountingInputStream class that can do the job.

Then you simply have to compare the read bytes count with the file length to have a progression.