ohair@286: /*
ohair@286:  * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package javax.activation;
ohair@286: 
ohair@286: import java.io.File;
ohair@286: 
ohair@286: /**
ohair@286:  * The FileTypeMap is an abstract class that provides a data typing
ohair@286:  * interface for files. Implementations of this class will
ohair@286:  * implement the getContentType methods which will derive a content
ohair@286:  * type from a file name or a File object. FileTypeMaps could use any
ohair@286:  * scheme to determine the data type, from examining the file extension
ohair@286:  * of a file (like the MimetypesFileTypeMap) to opening the file and
ohair@286:  * trying to derive its type from the contents of the file. The
ohair@286:  * FileDataSource class uses the default FileTypeMap (a MimetypesFileTypeMap
ohair@286:  * unless changed) to determine the content type of files.
ohair@286:  *
ohair@286:  * @see javax.activation.FileTypeMap
ohair@286:  * @see javax.activation.FileDataSource
ohair@286:  * @see javax.activation.MimetypesFileTypeMap
ohair@286:  *
ohair@286:  * @since 1.6
ohair@286:  */
ohair@286: 
ohair@286: public abstract class FileTypeMap {
ohair@286: 
ohair@286:     private static FileTypeMap defaultMap = null;
ohair@286: 
ohair@286:     /**
ohair@286:      * The default constructor.
ohair@286:      */
ohair@286:     public FileTypeMap() {
ohair@286:         super();
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Return the type of the file object. This method should
ohair@286:      * always return a valid MIME type.
ohair@286:      *
ohair@286:      * @param file A file to be typed.
ohair@286:      * @return The content type.
ohair@286:      */
ohair@286:     abstract public String getContentType(File file);
ohair@286: 
ohair@286:     /**
ohair@286:      * Return the type of the file passed in.  This method should
ohair@286:      * always return a valid MIME type.
ohair@286:      *
ohair@286:      * @param filename the pathname of the file.
ohair@286:      * @return The content type.
ohair@286:      */
ohair@286:     abstract public String getContentType(String filename);
ohair@286: 
ohair@286:     /**
ohair@286:      * Sets the default FileTypeMap for the system. This instance
ohair@286:      * will be returned to callers of getDefaultFileTypeMap.
ohair@286:      *
ohair@286:      * @param map The FileTypeMap.
ohair@286:      * @exception SecurityException if the caller doesn't have permission
ohair@286:      *                                  to change the default
ohair@286:      */
ohair@286:     public static void setDefaultFileTypeMap(FileTypeMap map) {
ohair@286:         SecurityManager security = System.getSecurityManager();
ohair@286:         if (security != null) {
ohair@286:             try {
ohair@286:                 // if it's ok with the SecurityManager, it's ok with me...
ohair@286:                 security.checkSetFactory();
ohair@286:             } catch (SecurityException ex) {
ohair@286:                 // otherwise, we also allow it if this code and the
ohair@286:                 // factory come from the same class loader (e.g.,
ohair@286:                 // the JAF classes were loaded with the applet classes).
ohair@286:                 if (FileTypeMap.class.getClassLoader() !=
ohair@286:                         map.getClass().getClassLoader())
ohair@286:                     throw ex;
ohair@286:             }
ohair@286:         }
ohair@286:         defaultMap = map;
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Return the default FileTypeMap for the system.
ohair@286:      * If setDefaultFileTypeMap was called, return
ohair@286:      * that instance, otherwise return an instance of
ohair@286:      * <code>MimetypesFileTypeMap</code>.
ohair@286:      *
ohair@286:      * @return The default FileTypeMap
ohair@286:      * @see javax.activation.FileTypeMap#setDefaultFileTypeMap
ohair@286:      */
ohair@286:     public static FileTypeMap getDefaultFileTypeMap() {
ohair@286:         // XXX - probably should be synchronized
ohair@286:         if (defaultMap == null)
ohair@286:             defaultMap = new MimetypesFileTypeMap();
ohair@286:         return defaultMap;
ohair@286:     }
ohair@286: }