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/* * @(#)FileTypeMap.java 1.9 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. * * This software is the proprietary information of Sun Microsystems, Inc. * Use is subject to license terms. * */ 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; } }