aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package javax.activation;
aoqi@0: 
aoqi@0: import java.io.File;
aoqi@0: import java.util.Map;
aoqi@0: import java.util.WeakHashMap;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * The FileTypeMap is an abstract class that provides a data typing
aoqi@0:  * interface for files. Implementations of this class will
aoqi@0:  * implement the getContentType methods which will derive a content
aoqi@0:  * type from a file name or a File object. FileTypeMaps could use any
aoqi@0:  * scheme to determine the data type, from examining the file extension
aoqi@0:  * of a file (like the MimetypesFileTypeMap) to opening the file and
aoqi@0:  * trying to derive its type from the contents of the file. The
aoqi@0:  * FileDataSource class uses the default FileTypeMap (a MimetypesFileTypeMap
aoqi@0:  * unless changed) to determine the content type of files.
aoqi@0:  *
aoqi@0:  * @see javax.activation.FileTypeMap
aoqi@0:  * @see javax.activation.FileDataSource
aoqi@0:  * @see javax.activation.MimetypesFileTypeMap
aoqi@0:  *
aoqi@0:  * @since 1.6
aoqi@0:  */
aoqi@0: 
aoqi@0: public abstract class FileTypeMap {
aoqi@0: 
aoqi@0:     private static FileTypeMap defaultMap = null;
aoqi@0:     private static Map<ClassLoader,FileTypeMap> map =
aoqi@0:                                 new WeakHashMap<ClassLoader,FileTypeMap>();
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * The default constructor.
aoqi@0:      */
aoqi@0:     public FileTypeMap() {
aoqi@0:         super();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return the type of the file object. This method should
aoqi@0:      * always return a valid MIME type.
aoqi@0:      *
aoqi@0:      * @param file A file to be typed.
aoqi@0:      * @return The content type.
aoqi@0:      */
aoqi@0:     abstract public String getContentType(File file);
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return the type of the file passed in.  This method should
aoqi@0:      * always return a valid MIME type.
aoqi@0:      *
aoqi@0:      * @param filename the pathname of the file.
aoqi@0:      * @return The content type.
aoqi@0:      */
aoqi@0:     abstract public String getContentType(String filename);
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Sets the default FileTypeMap for the system. This instance
aoqi@0:      * will be returned to callers of getDefaultFileTypeMap.
aoqi@0:      *
aoqi@0:      * @param fileTypeMap The FileTypeMap.
aoqi@0:      * @exception SecurityException if the caller doesn't have permission
aoqi@0:      *                                  to change the default
aoqi@0:      */
aoqi@0:     public static synchronized void setDefaultFileTypeMap(FileTypeMap fileTypeMap) {
aoqi@0:         SecurityManager security = System.getSecurityManager();
aoqi@0:         if (security != null) {
aoqi@0:             try {
aoqi@0:                 // if it's ok with the SecurityManager, it's ok with me...
aoqi@0:                 security.checkSetFactory();
aoqi@0:             } catch (SecurityException ex) {
aoqi@0:                 // otherwise, we also allow it if this code and the
aoqi@0:                 // factory come from the same (non-system) class loader (e.g.,
aoqi@0:                 // the JAF classes were loaded with the applet classes).
aoqi@0:                 if (FileTypeMap.class.getClassLoader() == null ||
aoqi@0:                     FileTypeMap.class.getClassLoader() !=
aoqi@0:                         fileTypeMap.getClass().getClassLoader())
aoqi@0:                     throw ex;
aoqi@0:             }
aoqi@0:         }
aoqi@0:         // remove any per-thread-context-class-loader FileTypeMap
aoqi@0:         map.remove(SecuritySupport.getContextClassLoader());
aoqi@0:         defaultMap = fileTypeMap;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return the default FileTypeMap for the system.
aoqi@0:      * If setDefaultFileTypeMap was called, return
aoqi@0:      * that instance, otherwise return an instance of
aoqi@0:      * <code>MimetypesFileTypeMap</code>.
aoqi@0:      *
aoqi@0:      * @return The default FileTypeMap
aoqi@0:      * @see javax.activation.FileTypeMap#setDefaultFileTypeMap
aoqi@0:      */
aoqi@0:     public static synchronized FileTypeMap getDefaultFileTypeMap() {
aoqi@0:         if (defaultMap != null)
aoqi@0:             return defaultMap;
aoqi@0: 
aoqi@0:         // fetch per-thread-context-class-loader default
aoqi@0:         ClassLoader tccl = SecuritySupport.getContextClassLoader();
aoqi@0:         FileTypeMap def = map.get(tccl);
aoqi@0:         if (def == null) {
aoqi@0:             def = new MimetypesFileTypeMap();
aoqi@0:             map.put(tccl, def);
aoqi@0:         }
aoqi@0:         return def;
aoqi@0:     }
aoqi@0: }