[Java] A variety of ways to get MIME type from a file __java

1, Mime-util:

The tool can detect the MIME type by detecting the file name extension or detecting the magic header two technical methods.

More reliable and lightweight, relying only on slf4j a package. It hasn't been updated in 2010 years.

POM

<dependency>
    <groupId>eu.medsea.mimeutil</groupId>
    <artifactid>mime-util</ artifactid>
    <version>2.1.3</version>
</dependency>

Sample code:

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  
    }  
}  

2, jmimemagic by detecting file suffix name to find the file type is obviously not a robust method. Jmimemagic is a Java toolkit that checks magic headers to determine the MIME type of a file or stream. Currently in the ongoing update, recommended use. POM

<dependency>
    <groupId>net.sf.jmimemagic</groupId>
    <artifactId>jmimemagic< /artifactid>
    <version>0.1.4</version>
</dependency>

Sample code

Magic parser = new Magic ();  
Getmagicmatch accepts Files or byte[],  
//which is nice if you want to test streams  
magicmatch match = PARSER.G Etmagicmatch (New File ("Gumby.gif"));  
System.out.println (Match.getmimetype ());  

3, Java.net.URL with the above mentioned matching suffix name similar. The mapping relationship between the suffix name and the mime-type is defined in [jre_home]\lib\content-types.properties the component is judged only by the file name extension Mime-type. Not very reliable.
Sample code (recommended)

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  
    }  
  

Sample code (not recommended: This is also the way to determine MIME type by extension and is slow)

Import java.net.*;  
  
public class fileutils{  
  the 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  
  }  
}  

4, Javax.activation.MimetypesFileTypeMap need to introduce Activation.jar this jar package, he can obtain from the website below http://java.sun.com/products/ Javabeans/glasgow/jaf.html.
This Mimetypesfilemap class maps the MIME type of a file, which is limited in the number of Mime-type lists defined in the resource file in the Activation.jar package, 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 looks in the following order to find the MIME type

First, you add files to an instance of Mimetypesfiletypemap by using a program
Finds a 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 (usually only in Activation.jar).

This approach is very interesting when you need to process a file named after an incoming generic file. The results come out fast because only the extension is used to guess the file's natural attributes 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"  
  }  
}