001 /* CommandMap.java -- Registry of available command objects.
002 Copyright (C) 2004, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.activation;
039
040 /**
041 * Registry of command objects available to the system.
042 *
043 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
044 * @version 1.1
045 */
046 public abstract class CommandMap
047 {
048
049 /* Class scope */
050
051 private static CommandMap defaultCommandMap;
052
053 /**
054 * Returns the default command map.
055 * This returns a MailcapCommandMap if no value has been set using
056 * <code>setDefaultCommandMap</code>.
057 */
058 public static CommandMap getDefaultCommandMap()
059 {
060 if (defaultCommandMap == null)
061 {
062 defaultCommandMap = new MailcapCommandMap();
063 }
064 return defaultCommandMap;
065 }
066
067 /**
068 * Sets the default command map.
069 * @param commandMap the new default command map
070 */
071 public static void setDefaultCommandMap(CommandMap commandMap)
072 {
073 SecurityManager security = System.getSecurityManager();
074 if (security != null)
075 {
076 try
077 {
078 security.checkSetFactory();
079 }
080 catch (SecurityException e)
081 {
082 if (commandMap != null && CommandMap.class.getClassLoader() !=
083 commandMap.getClass().getClassLoader())
084 {
085 throw e;
086 }
087 }
088 }
089 defaultCommandMap = commandMap;
090 }
091
092 /* Instance scope */
093
094 /**
095 * Returns the list of preferred commands for a MIME type.
096 * @param mimeType the MIME type
097 */
098 public abstract CommandInfo[] getPreferredCommands(String mimeType);
099
100 /**
101 * Returns the complete list of commands for a MIME type.
102 * @param mimeType the MIME type
103 */
104 public abstract CommandInfo[] getAllCommands(String mimeType);
105
106 /**
107 * Returns the command corresponding to the specified MIME type and
108 * command name.
109 * @param mimeType the MIME type
110 * @param cmdName the command name
111 */
112 public abstract CommandInfo getCommand(String mimeType, String cmdName);
113
114 /**
115 * Returns a DataContentHandler corresponding to the MIME type.
116 * @param mimeType the MIME type
117 */
118 public abstract DataContentHandler createDataContentHandler(String mimeType);
119
120 /**
121 * Get all the MIME types known to this command map.
122 * If the command map doesn't support this operation, null is returned.
123 * @return array of MIME types as strings, or null if not supported
124 * @since JAF 1.1
125 */
126 public String[] getMimeTypes()
127 {
128 return null;
129 }
130
131 /**
132 * Get the preferred command list from a MIME Type. The actual semantics
133 * are determined by the implementation of the CommandMap.
134 * <p>
135 * The <code>DataSource</code> provides extra information, such as
136 * the file name, that a CommandMap implementation may use to further
137 * refine the list of commands that are returned. The implementation
138 * in this class simply calls the <code>getPreferredCommands</code>
139 * method that ignores this argument.
140 * @param mimeType the MIME type
141 * @param ds a DataSource for the data
142 * @return the CommandInfo classes that represent the command Beans.
143 * @since JAF 1.1
144 */
145 public CommandInfo[] getPreferredCommands(String mimeType,
146 DataSource ds)
147 {
148 return getPreferredCommands(mimeType);
149 }
150
151 /**
152 * Get all the available commands for this type. This method
153 * should return all the possible commands for this MIME type.
154 * <p>
155 * The <code>DataSource</code> provides extra information, such as
156 * the file name, that a CommandMap implementation may use to further
157 * refine the list of commands that are returned. The implementation
158 * in this class simply calls the <code>getAllCommands</code>
159 * method that ignores this argument.
160 * @param mimeType the MIME type
161 * @param ds a DataSource for the data
162 * @return the CommandInfo objects representing all the commands.
163 * @since JAF 1.1
164 */
165 public CommandInfo[] getAllCommands(String mimeType, DataSource ds)
166 {
167 return getAllCommands(mimeType);
168 }
169
170 /**
171 * Get the default command corresponding to the MIME type.
172 * <p>
173 * The <code>DataSource</code> provides extra information, such as
174 * the file name, that a CommandMap implementation may use to further
175 * refine the command that is chosen. The implementation
176 * in this class simply calls the <code>getCommand</code>
177 * method that ignores this argument.
178 * @param mimeType the MIME type
179 * @param cmdName the command name
180 * @param ds a DataSource for the data
181 * @return the CommandInfo corresponding to the command.
182 * @since JAF 1.1
183 */
184 public CommandInfo getCommand(String mimeType, String cmdName,
185 DataSource ds)
186 {
187 return getCommand(mimeType, cmdName);
188 }
189
190 /**
191 * Locate a DataContentHandler that corresponds to the MIME type.
192 * The mechanism and semantics for determining this are determined
193 * by the implementation of the particular CommandMap.
194 * <p>
195 * The <code>DataSource</code> provides extra information, such as
196 * the file name, that a CommandMap implementation may use to further
197 * refine the choice of DataContentHandler. The implementation
198 * in this class simply calls the <code>createDataContentHandler</code>
199 * method that ignores this argument.
200 * @param mimeType the MIME type
201 * @param ds a DataSource for the data
202 * @return the DataContentHandler for the MIME type
203 * @since JAF 1.1
204 */
205 public DataContentHandler createDataContentHandler(String mimeType,
206 DataSource ds)
207 {
208 return createDataContentHandler(mimeType);
209 }
210
211 }