/*
* Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package javax.activation;
import java.io.File;
/**
* The FileTypeMap is an abstract class that provides a data typing
* interface for files. Implementations of this class will
* implement the getContentType methods which will derive a content
* type from a file name or a File object. FileTypeMaps could use any
* scheme to determine the data type, from examining the file extension
* of a file (like the MimetypesFileTypeMap) to opening the file and
* trying to derive its type from the contents of the file. The
* FileDataSource class uses the default FileTypeMap (a MimetypesFileTypeMap
* unless changed) to determine the content type of files.
*
* @see javax.activation.FileTypeMap
* @see javax.activation.FileDataSource
* @see javax.activation.MimetypesFileTypeMap
*
* @since 1.6
*/
public abstract class FileTypeMap {
private static FileTypeMap defaultMap = null;
/**
* The default constructor.
*/
public FileTypeMap() {
super();
}
/**
* Return the type of the file object. This method should
* always return a valid MIME type.
*
* @param file A file to be typed.
* @return The content type.
*/
abstract public String getContentType(File file);
/**
* Return the type of the file passed in. This method should
* always return a valid MIME type.
*
* @param filename the pathname of the file.
* @return The content type.
*/
abstract public String getContentType(String filename);
/**
* Sets the default FileTypeMap for the system. This instance
* will be returned to callers of getDefaultFileTypeMap.
*
* @param map The FileTypeMap.
* @exception SecurityException if the caller doesn't have permission
* to change the default
*/
public static void setDefaultFileTypeMap(FileTypeMap map) {
SecurityManager security = System.getSecurityManager();
if (security != null) {
try {
// if it's ok with the SecurityManager, it's ok with me...
security.checkSetFactory();
} catch (SecurityException ex) {
// otherwise, we also allow it if this code and the
// factory come from the same class loader (e.g.,
// the JAF classes were loaded with the applet classes).
if (FileTypeMap.class.getClassLoader() !=
map.getClass().getClassLoader())
throw ex;
}
}
defaultMap = map;
}
/**
* Return the default FileTypeMap for the system.
* If setDefaultFileTypeMap was called, return
* that instance, otherwise return an instance of
* <code>MimetypesFileTypeMap</code>.
*
* @return The default FileTypeMap
* @see javax.activation.FileTypeMap#setDefaultFileTypeMap
*/
public static FileTypeMap getDefaultFileTypeMap() {
// XXX - probably should be synchronized
if (defaultMap == null)
defaultMap = new MimetypesFileTypeMap();
return defaultMap;
}
}