JavaMail and non-ASCII character in filenames - jakarta-mail

Question

I can send attachments that have non-ascii filenames in JavaMail but I am not able to download them. I am getting java.io.FileNotFoundException specifically for those attachments whose file names contain non-ascii characters.
FYI: I am using something like messageBodyPart.setFileName(MimeUtility.encodeText(filename[i])) to encode the text and MimeUtility.decodeText(bodyPart.getFileName()) to decode the non-ascii file names
Is there a workaround for this?
EDIT
#Bill, here is part of my code that reads attachments. I have also added the properties.setProperty("mail.mime.decodeparameters", "true") and properties.setProperty("mail.mime.decodefilename", "true") properties in my code.
if (message[a].getContent() instanceof MimeMultipart) {
Multipart multipart = (Multipart) message[a].getContent();
for (int i = 0; i < multipart.getCount(); i++) {
bodyPart = multipart.getBodyPart(i);
disposition = bodyPart.getDisposition();
if (disposition != null && (disposition.equals(BodyPart.ATTACHMENT) || (disposition.equals(BodyPart.INLINE)))) {
DataHandler handler = bodyPart.getDataHandler();
String path = bodyPart.getFileName();
String[] str = path.split("/");
String fileName = str[str.length - 1];
String filePath = ReadConfigPropertiesFile.getPropertyValue("server.buildpath");
System.out.println(fileName);
File tempDir = new File(filePath + user);
if (!tempDir.exists()) {
tempDir.mkdir();
}
File saveFile = new File(tempDir + "/" + fileName);
int count = 0;
while (saveFile.exists()) {
count++;
saveFile = new File(tempDir + "/" + count + "_" + fileName);
}
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(saveFile));
byte[] buff = new byte[2048];
InputStream is = bodyPart.getInputStream();
int ret = 0;
while ((ret = is.read(buff)) > 0) {
bos.write(buff, 0, ret);
}
bos.close();
is.close();
//System.out.println(bodyPart.getContentType());
}else {
//display body (message) of the attachment;
//System.out.println(bodyPart.getContent().toString());
}
}
}
The above code raises the FileNotFoundException exception at BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(saveFile)) line and this is getting raised for the attachments whose file names are non-ascii characters (something like ሰላም.pdf). Every thing else works fine.

Answer 1

This answer taken from comment of #semytech (OP). It was hard to find it there, so I will add it as answer for more visibility. It helped me with hebrew filenames.
MimeBodyPart attachment = new MimeBodyPart();
attachment.setFileName(MimeUtility.encodeText(filename, "UTF-8", null));

Answer 2

You should never need to do the encoding or decoding yourself.
There are two sets of properties you can set to tell JavaMail to do the encoding/decoding for you:
mail.mime.encodefilename/mail.mime.decodefilename
mail.mime.encodeparameters/mail.mime.decodeparameters
See the javadocs for the javax.mail.internet package for details.
The first set uses a non-standard encoding technique, similar to what you're doing yourself. This works fine with some older mailers that use this technique.
The second set uses a MIME standard encoding technique. This version works with most modern mailers.
None of this explains why you're getting FileNotFoundException, but then you didn't provide enough detail to know what you're doing when you get the exception.