eu.medsea.mimeutil.detector
Class ExtensionMimeDetector

java.lang.Object
  eu.medsea.mimeutil.detector.MimeDetector
      eu.medsea.mimeutil.detector.ExtensionMimeDetector

public class ExtensionMimeDetector
extends MimeDetector

The extension mime mappings are loaded in the following way.

1. Load the properties file from the mime utility jar named eu.medsea.mimeutil.mime-types.properties.
2. Locate and load a file named .mime-types.properties from the users home directory if one exists.
3. Locate and load a file named mime-types.properties from the classpath if one exists
4. locate and load a file named by the JVM property mime-mappings i.e. -Dmime-mappings=../my-mime-types.properties

Each property file loaded will add to the list of extensions understood by MimeUtil. If there is a clash of extension names then the last one loaded wins, i.e they are not adative, this makes it possible to completely change the mime types associated to a file extension declared in previously loaded property files. The extensions are also case sensitive meaning that bat, bAt, BAT and Bat can all be recognised individually. If however, no match is found using case sensitive matching then it will perform an insensitive match by lower casing the extension of the file to be matched first.

Fortunately, we have compiled a relatively large list of mappings into a java properties file from information gleaned from many sites on the Internet. This file resides in the eu.medsea.util.mime-types.properties file and is not guaranteed to be correct or contain all the known mappings for a file extension type. This is not a complete or exhaustive list as that would have proven too difficult to compile for this project. So instead we give you the opportunity to extend and override these mappings for yourself as defined above. Obviously, to use this method you don't actually need a file object, you just need a file name with an extension. Also, if you have given or renamed a file using a different extension than the one that it would normally be associated with then this mapping will return the wrong mime-type and if the file has no extension at all, such as Make, then it's not going to be possible to determine a mime type using this technique

We acquired many mappings from many different sources on the net for the extension mappings. The internal list is quite large and there can be many associated mime types. These may not match what you are expecting so you can add the mapping you want to change to your own property file following the rules above. If you provide a mapping for an extension then any previously loaded mappings will be removed and only the mappings you define will be returned. This can be used to map certain extensions that are incorrectly returned for our environment defined in the internal property file.

If we have not provided a mapping for a file extension that you know the mime type for you can add this to your custom property files so that a correct mime type is returned for you.

We use the application/directory mime type to identify directories. Even though this is not an official mime type it seems to be well accepted on the net as an unofficial mime type so we thought it was OK for us to use as well.

This class is auto loaded by MimeUtil as it has an entry in the file called MimeDetectors. MimeUtil reads this file at startup and calls Class.forName() on each entry found. This mean the MimeDetector must have a no arg constructor.

Author:

Steven McArdle.

Constructor Summary

ExtensionMimeDetector()

Method Summary

String	getDescription() Abstract method to be implement by concrete MimeDetector(s).
Collection	getMimeTypesByteArray(byte[] data) This method is required by the abstract MimeDetector class.
Collection	getMimeTypesFile(File file) Get the mime type of a file using file extension mappings.
Collection	getMimeTypesInputStream(InputStream in) This method is required by the abstract MimeDetector class.

Methods inherited from class eu.medsea.mimeutil.detector.MimeDetector

addMimeHandler, getMimeHandlers, getMimeTypes, getMimeTypes, getMimeTypes, getMimeTypes, getMimeTypes, getName, removeMimeHandler

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExtensionMimeDetector

public ExtensionMimeDetector()

Method Detail

getDescription

public String getDescription()

Description copied from class: MimeDetector

Abstract method to be implement by concrete MimeDetector(s).

Specified by:

getDescription in class MimeDetector

Returns:

description of this MimeDetector

getMimeTypesFile

public Collection getMimeTypesFile(File file)
                            throws MimeException

Get the mime type of a file using file extension mappings. The file path can be a relative or absolute path or can be a completely non-existent file as only the extension is important here.

Specified by:

getMimeTypesFile in class MimeDetector

Parameters:

file - is a File object that points to a file or directory.

Returns:

collection of the matched mime types.

Throws:

MimeException - if the file cannot be parsed.

getMimeTypesInputStream

public Collection getMimeTypesInputStream(InputStream in)
                                   throws UnsupportedOperationException

This method is required by the abstract MimeDetector class. As we do not support extension mapping of streams we just throw an UnsupportedOperationException. This ensures that the getMimeTypes(...) methods ignore this method. We could also have just returned an empty collection.

Specified by:

getMimeTypesInputStream in class MimeDetector

Parameters:

in - InputStream. If the InputStream does not support the mark() and reset() methods it will throw an exception.

Returns:

collection of matched MimeType(s)

Throws:

UnsupportedOperationException

getMimeTypesByteArray

public Collection getMimeTypesByteArray(byte[] data)
                                 throws UnsupportedOperationException

This method is required by the abstract MimeDetector class. As we do not support extension mapping of byte arrays we just throw an UnsupportedOperationException. This ensures that the getMimeTypes(...) methods ignore this method. We could also have just returned an empty collection.

Specified by:

getMimeTypesByteArray in class MimeDetector

Parameters:

data - byte []. Is a byte array that you want to parse for matching mime types.

Returns:

collection of matched MimeType(s)

Throws:

UnsupportedOperationException