Estimate if file is MIME type

Question

This method should be check if a file is MIME type. To achieve this goal I am using method probeContentType().
However maybe is another way to decide same question. Which are the other alternatives (if there are any)?

Code:

class ProbeContentTypeCheker implements Checker {

    @Override
    public boolean check(File fileCheck) {
        try {
            Path filePath = FileSystems.getDefault().getPath(
                    fileCheck.getAbsolutePath());
            if ((Files.probeContentType(filePath) != null)) {
                return true;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        return false;
    }
}

Question:

Are there other alternatives to check MIME type in files?

Dror Bereznitsky · Accepted Answer · 2013-03-09T20:41:10.787

There are 2 approaches for getting a file mime type:

Identifying by the file's magic number - this is a reliable approach but it requires reading information from the file
Guessing it by the file extension - this is a fast approach, but can be less accurate

The following solution use the 1st approach:

Apache Tika - a toolkit for detecting and extracting metadata and structured text content from various documents using existing parser libraries
JMimeMagic - a Java library for determining the MIME type of files or streams
mime-util - enable Java programs to detect MIME types based on file extensions, magic data and content sniffing

The following solution use the 2nd approach:

javax.activation.MimetypesFileTypeMap - this part of the JavaBeans Activation Framework. The MimetypesFileTypeMap looks in various places in the user's system for MIME types file entries.
Using java.net.URL - mapping between the extension and the mime-type is defined in the file [jre_home]/lib/content-types.properties

For some more information see this post

Can you add another variants checking MIME types (enumerate list)? — catch23, Mar 10 '13 at 10:15
Do you mind me asking, if you can see at [this SO Question](http://stackoverflow.com/questions/15325047/check-file-of-mime-type-with-jmimemagic). — catch23, Mar 10 '13 at 22:00
Thanks. I ended up using `mime-util`, it works great even on a 9GB+ file. — Bob, Sep 15 '13 at 20:04

score 1 · Answer 2 · answered Mar 01 '13 at 10:31

1

You can use String mimeType = new MimetypesFileTypeMap().getContentType(theFile);.

Note that if no MIME type is found, application/octet-stream is returned instead of null.

answered Mar 01 '13 at 10:31

sp00m

47,968
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`getContentType(theFile)` => Can we check there `theFile.getAbsolutePath()`? And after fixed - is this valid [`check(File fileCheck)`](http://pastebin.com/SpmFGZGf)? – catch23 Mar 01 '13 at 11:10
1

public boolean check(File fileCheck) { String mimeType = new MimetypesFileTypeMap().getContentType(fileCheck); if (mimeType == null) { return false; } return true; } - Is this correct? – catch23 Mar 01 '13 at 11:20
@nazar_art No, since as I said, if no MIME type is found, `application/octet-stream` is returned instead of `null`. `application/octet-stream` is usually the default MIME type of any file, if no other more specific has been found. – sp00m Mar 01 '13 at 13:13
1

If this [MimetypesFileTypeMap()](http://pastebin.com/bcpyEgrw) isn't correct? How we can repair this method and to prove good work file check method? – catch23 Mar 01 '13 at 14:47
Copy the source of class MimetypesFileTypeMap and set static variable 'defaultType' null. But I would not do that unless there is a specific reason. It is possible that you may need additional mime types added, see http://stackoverflow.com/questions/6308142/adding-mimetypes-to-mimetypesfiletypemap – Adisesha Mar 05 '13 at 13:06
@Adi What is better variant at this situations? – catch23 Mar 09 '13 at 20:53

score 0 · Answer 3 · answered Mar 08 '13 at 11:00

0

Another alternative is to Use URLConnection.guessContentTypeFromName(String fileName) if you cannot use Java 7. Note that if the content type cannot be guessed, the method will return null.

answered Mar 08 '13 at 11:00

fboulay

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Estimate if file is MIME type

3 Answers3

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