Several ways to get file MIME types in Java (GO)

This article was reproduced from: http://hotsunshine.iteye.com/blog/857485

Using Javax.activation.MimetypesFileTypeMap
Need to introduce Activation.jar this jar package, he can get http://java.sun.com/products/javabeans/glasgow/jaf.html from this website.
The Mimetypesfilemap class maps a file's MIME type, which is defined in the resource file in the Activation.jar package.

Sample code

Import Javax.activation.MimetypesFileTypeMap;
Import Java.io.File;

Class GetMimeType {
public static void Main (String args[]) {
File F = new file ("Gumby.gif");
System.out.println ("Mime Type of" + f.getname () + "is" +
New Mimetypesfiletypemap (). getContentType (f));
Expected output:
"Mime Type of Gumby.gif is Image/gif"
}
}

The number of Mime-type in your own list is limited, but it provides a way for you to easily add more MIME types

Mimetypesfiletypemap will find the MIME type of the file in many parts of the user's system. When a request to find a MIME type arrives, he will find the MIME type in the following order

You first add the file to an instance of Mimetypesfiletypemap by using a program
Locate the file under the user's home path. mime.types
Find Files <java.home>/lib/mime.types
Find files or resources meta-inf/mime.types
Find files or resource Meta-inf/mimetypes.default (typically found only in Activation.jar).

This method is very interesting when you need to process a file named for an incoming generic file. The results come out fast because only the extension is used to guess the nature of the file's properties

Using Java.net.URL
Warning: This method is very slow
Similar to the above-mentioned match suffix name. The mapping of suffix names and mime-type is defined in [jre_home]\lib\content-types.properties this file

Import java.net.*;

public class fileutils{
public static string GetMimeType (String fileUrl)
Throws Java.io.IOException, Malformedurlexception
{
String type = null;
URL u = new URL (fileUrl);
URLConnection UC = null;
UC = U.openconnection ();
Type = Uc.getcontenttype ();
return type;
}

public static void Main (String args[]) throws Exception {
System.out.println (Fileutils.getmimetype ("File://c:/temp/test.TXT"));
Output:text/plain
}
}

From R. Lovelock's Notes:
I'm trying to find the best way to get the type of MIME type and find that your discovery is useful, but now I find that it can be found by urlconnection and not as slow as you describe.

Import Java.net.FileNameMap;
Import java.net.URLConnection;

public class FileUtils {

public static string GetMimeType (String fileUrl)
Throws Java.io.IOException
{
fileNameMap fileNameMap = Urlconnection.getfilenamemap ();
String type = filenamemap.getcontenttypefor (FILEURL);
return type;
}

public static void Main (String args[]) throws Exception {
System.out.println (Fileutils.getmimetype ("File://c:/temp/test.TXT"));
Output:text/plain
}
}
}

Using Apache Tika
Tika is a sub-project of Lucene, which is a toolkit for finding and extracting metadata and structured text content in various documents through an existing parsing library.
This package provides support for crime file types, including office2007 (Docs/pptx/xlsx/etc ... ）

Apache Tika
Tika has a lot of dependent packages, about 20 jar packs! But it can do more than just detect file types, for example, you can parse a PDF or doc file and easily get text and metadata

Import Java.io.File;
Import Java.io.FileInputStream;

Import Org.apache.tika.metadata.Metadata;
Import Org.apache.tika.parser.AutoDetectParser;
Import Org.apache.tika.parser.Parser;
Import Org.apache.tika.sax.BodyContentHandler;
Import Org.xml.sax.ContentHandler;

public class Main {

public static void Main (String args[]) throws Exception {

FileInputStream is = null;
try {
File F = new file ("C:/temp/mime/test.docx");
is = new FileInputStream (f);

ContentHandler ContentHandler = new Bodycontenthandler ();
Metadata Metadata = new Metadata ();
Metadata.set (Metadata.resource_name_key, F.getname ());
Parser Parser = new Autodetectparser ();
Ooxmlparser parser = new Ooxmlparser ();
Parser.parse (IS, contenthandler, metadata);
System.out.println ("Mime:" + metadata.get (metadata.content_type));
System.out.println ("Title:" + metadata.get (metadata.title));
System.out.println ("Author:" + metadata.get (metadata.author));
System.out.println ("content:" + contenthandler.tostring ());
}
catch (Exception e) {
E.printstacktrace ();
}
finally {
if (is! = null) is.close ();
}
}
}

 

Using Jmimemagic
It is obviously not a robust method to find the file type by detecting the file suffix name. The Jmimemagic library provides a more robust detection method, a Java toolkit that examines the MIME type of a file or stream by examining the magic headers

Snippet for Jmimemagic Lib
http://sourceforge.net/projects/jmimemagic/

Magic parser = new Magic ();
Getmagicmatch accepts Files or byte[],
Which is nice if you want to test streams
MagicMatch match = Parser.getmagicmatch (new File ("Gumby.gif"));
System.out.println (Match.getmimetype ());

Using Mime-util

Another tool is mime-util, a tool that can detect MIME types by detecting file extensions or detecting magic headers in two technical ways

Import Eu.medsea.mimeutil.MimeUtil;
public class Main {
public static void Main (string[] args) {
Mimeutil.registermimedetector ("Eu.medsea.mimeutil.detector.MagicMimeMimeDetector");
File F = new file ("C:/temp/mime/test.doc");
collection<?> mimetypes = Mimeutil.getmimetypes (f);
System.out.println (mimetypes);
Output:application/msword
}
}

The good thing about Mime-util is that it is lightweight and relies only on slf4j a package

Several ways to get file MIME types in Java (GO)