Critical Description
I have an eml file that can be detected as message/rfc822 only if the file extension is .eml, otherwise it will be detected as text/plain. Following is the code that I use to detect the file type and extension.
TikaConfig config = TikaConfigFactory.getTikaConfig();
Detector detector = config.getDetector();
Metadata metadata = new Metadata();
TikaInputStream stream = TikaInputStream.get(fis = new FileInputStream(filePath));
metadata.add(Metadata.RESOURCE_NAME_KEY, filePath);
MediaType mediaType = detector.detect(stream, metadata);
MimeType mimeType = config.getMimeRepository().forName(mediaType.toString());
String tikaExtension = mimeType.getExtension();
When the sample file has .eml extension, mimeType is message/rfc822 and tikaExtension is eml. When I change the extension to .txt, mimeType is text/plain and tikaExtension is .txt.
The same mimeType and tikaExtension should be detected regardless the file extension.