How to get filename of all attachements of email?

问题

I am trying to get the filename of all the attachements of emails using java and imap.My code is:

MimeMessage msg = (MimeMessage) messages[i];
String fileName = msg.getFileName();
System.out.println("The file name of this attachment is " + fileName);

but it prints null always even if email contain attachment..I have seen different codes on SO but none worked...and I don't know what to do if attachment is more than one .
PS:I only want to get the filename and don't want to download attachments.

回答1:

First, to determine if a message may contain attachments using the following code:

// suppose 'message' is an object of type Message
String contentType = message.getContentType();

if (contentType.contains("multipart")) {
    // this message may contain attachment
}

Then we must iterate through each part in the multipart to identify which part contains the attachment, as follows:

Multipart multiPart = (Multipart) message.getContent();

for (int i = 0; i < multiPart.getCount(); i++) {
    MimeBodyPart part = (MimeBodyPart) multiPart.getBodyPart(i);
    if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition())) {
        // this part is attachment
        // code to save attachment...
    }
}

And to save the file, you could do:

part.saveFile("D:/Attachment/" + part.getFileName());

Source

来源：https://stackoverflow.com/questions/23882797/how-to-get-filename-of-all-attachements-of-email