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Is there a java library equivalent to file command in unix

Answer 1

+3 A:

You could look at jmimemagic (tutorial). We've been using it for a while to validate uploaded images. No problems so far.

sfussenegger 2010-04-28 11:43:32

Answer 2

+5 A:

A quick google search (for the admittedly non-obvious) "java magic file detection" brings up a fairly nice looking article, "Get the Mime Type from a File" which suggests you use one of the following:

Hasturkun 2010-04-28 11:46:20

Thanks.I think one of these two should do the trick. Its really documents and images I need.

Shervin 2010-04-28 17:28:05

Answer 3

+1 A:

I am not sure it is exactly what you are looking for, but the following link can maybe help you :

http://www.rgagnon.com/javadetails/java-0487.html

Laurent 2010-04-28 11:47:20

+1 for giving the JDK-only solution. I'm not sure how good that method is, but it could be what the user is looking for.

bkail 2010-04-28 13:37:07

@bkail `javax.activation.MimetypesFileTypeMap` only checks the file extension which surely isn't a reliable way of determining "if the file is really what I want it to be"

sfussenegger 2010-04-28 14:15:24

Yes the JDK solution is not working like `file` in unix. `file` really looks at the file and tells what it is. Doesn't care about extension like windows does

Shervin 2010-04-28 17:26:39

@sfussenegger java.net.URLConnection.guessContentTypeFromStream(InputStream) surely does not use file extensions to make its determination.

bkail 2010-04-29 14:21:53

@bkail That wasn't mentioned in the linked article, was it? Anyway, it's not working reliably. I've just tried and it failed for a simple jpg image.

sfussenegger 2010-04-29 14:53:17

@sfussenegger Huh, I thought getContent/getContentType used guessContentTypeFromStream. Ah, apparently only for "jar:" URLs. Thanks for the clarification...

bkail 2010-04-29 15:55:07

Answer 4

+1 A:

Have a look at mime-utils. It works with content and/or with extensions.

openCage 2010-04-28 12:09:08

Answer 5

A:

The closest thing in the JDK is URLConnection.guessContentTypeFromStream

finnw 2010-05-18 12:51:33

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Is there a java library equivalent to file command in unix

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