1 |
771 |
jeremybenn |
/* Preferences -- Preference node containing key value entries and subnodes
|
2 |
|
|
Copyright (C) 2001, 2004, 2005, 2006 Free Software Foundation, Inc.
|
3 |
|
|
|
4 |
|
|
This file is part of GNU Classpath.
|
5 |
|
|
|
6 |
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
7 |
|
|
it under the terms of the GNU General Public License as published by
|
8 |
|
|
the Free Software Foundation; either version 2, or (at your option)
|
9 |
|
|
any later version.
|
10 |
|
|
|
11 |
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
12 |
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License
|
17 |
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
18 |
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
19 |
|
|
02110-1301 USA.
|
20 |
|
|
|
21 |
|
|
Linking this library statically or dynamically with other modules is
|
22 |
|
|
making a combined work based on this library. Thus, the terms and
|
23 |
|
|
conditions of the GNU General Public License cover the whole
|
24 |
|
|
combination.
|
25 |
|
|
|
26 |
|
|
As a special exception, the copyright holders of this library give you
|
27 |
|
|
permission to link this library with independent modules to produce an
|
28 |
|
|
executable, regardless of the license terms of these independent
|
29 |
|
|
modules, and to copy and distribute the resulting executable under
|
30 |
|
|
terms of your choice, provided that you also meet, for each linked
|
31 |
|
|
independent module, the terms and conditions of the license of that
|
32 |
|
|
module. An independent module is a module which is not derived from
|
33 |
|
|
or based on this library. If you modify this library, you may extend
|
34 |
|
|
this exception to your version of the library, but you are not
|
35 |
|
|
obligated to do so. If you do not wish to do so, delete this
|
36 |
|
|
exception statement from your version. */
|
37 |
|
|
|
38 |
|
|
package java.util.prefs;
|
39 |
|
|
|
40 |
|
|
import gnu.classpath.ServiceFactory;
|
41 |
|
|
import gnu.java.util.prefs.NodeReader;
|
42 |
|
|
|
43 |
|
|
import java.io.IOException;
|
44 |
|
|
import java.io.InputStream;
|
45 |
|
|
import java.io.OutputStream;
|
46 |
|
|
import java.security.AccessController;
|
47 |
|
|
import java.security.Permission;
|
48 |
|
|
import java.security.PrivilegedAction;
|
49 |
|
|
import java.util.Iterator;
|
50 |
|
|
|
51 |
|
|
/**
|
52 |
|
|
* Preference node containing key value entries and subnodes.
|
53 |
|
|
* <p>
|
54 |
|
|
* There are two preference node trees, a system tree which can be accessed
|
55 |
|
|
* by calling <code>systemRoot()</code> containing system preferences usefull
|
56 |
|
|
* for all users, and a user tree that can be accessed by calling
|
57 |
|
|
* <code>userRoot()</code> containing preferences that can differ between
|
58 |
|
|
* different users. How different users are identified is implementation
|
59 |
|
|
* depended. It can be determined by Thread, Access Control Context or Subject.
|
60 |
|
|
* <p>
|
61 |
|
|
* This implementation uses the "java.util.prefs.PreferencesFactory" system
|
62 |
|
|
* property to find a class that implement <code>PreferencesFactory</code>
|
63 |
|
|
* and initialized that class (if it has a public no arguments contructor)
|
64 |
|
|
* to get at the actual system or user root. If the system property is not set,
|
65 |
|
|
* or the class cannot be initialized it uses the default implementation
|
66 |
|
|
* <code>gnu.java.util.prefs.FileBasedFactory</code>.
|
67 |
|
|
* <p>
|
68 |
|
|
* Besides the two static method above to get the roots of the system and user
|
69 |
|
|
* preference node trees there are also two convenience methods to access the
|
70 |
|
|
* default preference node for a particular package an object is in. These are
|
71 |
|
|
* <code>userNodeForPackage()</code> and <code>systemNodeForPackage()</code>.
|
72 |
|
|
* Both methods take an Object as an argument so accessing preferences values
|
73 |
|
|
* can be as easy as calling <code>Preferences.userNodeForPackage(this)</code>.
|
74 |
|
|
* <p>
|
75 |
|
|
* Note that if a security manager is installed all static methods check for
|
76 |
|
|
* <code>RuntimePermission("preferences")</code>. But if this permission is
|
77 |
|
|
* given to the code then it can access and change all (user) preference nodes
|
78 |
|
|
* and entries. So you should be carefull not to store to sensitive information
|
79 |
|
|
* or make security decissions based on preference values since there is no
|
80 |
|
|
* more fine grained control over what preference values can be changed once
|
81 |
|
|
* code has been given the correct runtime permission.
|
82 |
|
|
* <p>
|
83 |
|
|
* XXX
|
84 |
|
|
*
|
85 |
|
|
* @since 1.4
|
86 |
|
|
* @author Mark Wielaard (mark@klomp.org)
|
87 |
|
|
*/
|
88 |
|
|
public abstract class Preferences {
|
89 |
|
|
|
90 |
|
|
// Static Fields
|
91 |
|
|
|
92 |
|
|
/**
|
93 |
|
|
* Default PreferencesFactory class used when the system property
|
94 |
|
|
* "java.util.prefs.PreferencesFactory" is not set.
|
95 |
|
|
*/
|
96 |
|
|
private static final String defaultFactoryClass
|
97 |
|
|
= "gnu.java.util.prefs.FileBasedFactory";
|
98 |
|
|
|
99 |
|
|
/** Permission needed to access system or user root. */
|
100 |
|
|
private static final Permission prefsPermission
|
101 |
|
|
= new RuntimePermission("preferences");
|
102 |
|
|
|
103 |
|
|
/**
|
104 |
|
|
* The preferences factory object that supplies the system and user root.
|
105 |
|
|
* Set and returned by the getFactory() method.
|
106 |
|
|
*/
|
107 |
|
|
private static PreferencesFactory factory;
|
108 |
|
|
|
109 |
|
|
/** Maximum node name length. 80 characters. */
|
110 |
|
|
public static final int MAX_NAME_LENGTH = 80;
|
111 |
|
|
|
112 |
|
|
/** Maximum entry key length. 80 characters. */
|
113 |
|
|
public static final int MAX_KEY_LENGTH = 80;
|
114 |
|
|
|
115 |
|
|
/** Maximum entry value length. 8192 characters. */
|
116 |
|
|
public static final int MAX_VALUE_LENGTH = 8192;
|
117 |
|
|
|
118 |
|
|
// Constructors
|
119 |
|
|
|
120 |
|
|
/**
|
121 |
|
|
* Creates a new Preferences node. Can only be used by subclasses.
|
122 |
|
|
* Empty implementation.
|
123 |
|
|
*/
|
124 |
|
|
protected Preferences() {}
|
125 |
|
|
|
126 |
|
|
// Static methods
|
127 |
|
|
|
128 |
|
|
/**
|
129 |
|
|
* Returns the system preferences root node containing usefull preferences
|
130 |
|
|
* for all users. It is save to cache this value since it should always
|
131 |
|
|
* return the same preference node.
|
132 |
|
|
*
|
133 |
|
|
* @return the root system preference node
|
134 |
|
|
* @exception SecurityException when a security manager is installed and
|
135 |
|
|
* the caller does not have <code>RuntimePermission("preferences")</code>.
|
136 |
|
|
*/
|
137 |
|
|
public static Preferences systemRoot() throws SecurityException {
|
138 |
|
|
// Get the preferences factory and check for permission
|
139 |
|
|
PreferencesFactory factory = getFactory();
|
140 |
|
|
|
141 |
|
|
return factory.systemRoot();
|
142 |
|
|
}
|
143 |
|
|
|
144 |
|
|
/**
|
145 |
|
|
* Returns the user preferences root node containing preferences for the
|
146 |
|
|
* the current user. How different users are identified is implementation
|
147 |
|
|
* depended. It can be determined by Thread, Access Control Context or
|
148 |
|
|
* Subject.
|
149 |
|
|
*
|
150 |
|
|
* @return the root user preference node
|
151 |
|
|
* @exception SecurityException when a security manager is installed and
|
152 |
|
|
* the caller does not have <code>RuntimePermission("preferences")</code>.
|
153 |
|
|
*/
|
154 |
|
|
public static Preferences userRoot() throws SecurityException {
|
155 |
|
|
// Get the preferences factory and check for permission
|
156 |
|
|
PreferencesFactory factory = getFactory();
|
157 |
|
|
return factory.userRoot();
|
158 |
|
|
}
|
159 |
|
|
|
160 |
|
|
/**
|
161 |
|
|
* Private helper method for <code>systemRoot()</code> and
|
162 |
|
|
* <code>userRoot()</code>. Checks security permission and instantiates the
|
163 |
|
|
* correct factory if it has not yet been set.
|
164 |
|
|
* <p>
|
165 |
|
|
* When the preferences factory has not yet been set this method first
|
166 |
|
|
* tries to get the system propery "java.util.prefs.PreferencesFactory"
|
167 |
|
|
* and tries to initializes that class. If the system property is not set
|
168 |
|
|
* or initialization fails it returns an instance of the default factory
|
169 |
|
|
* <code>gnu.java.util.prefs.FileBasedPreferencesFactory</code>.
|
170 |
|
|
*
|
171 |
|
|
* @return the preferences factory to use
|
172 |
|
|
* @exception SecurityException when a security manager is installed and
|
173 |
|
|
* the caller does not have <code>RuntimePermission("preferences")</code>.
|
174 |
|
|
*/
|
175 |
|
|
private static PreferencesFactory getFactory() throws SecurityException {
|
176 |
|
|
|
177 |
|
|
// First check for permission
|
178 |
|
|
SecurityManager sm = System.getSecurityManager();
|
179 |
|
|
if (sm != null) {
|
180 |
|
|
sm.checkPermission(prefsPermission);
|
181 |
|
|
}
|
182 |
|
|
|
183 |
|
|
// Get the factory
|
184 |
|
|
if (factory == null) {
|
185 |
|
|
// Caller might not have enough permissions
|
186 |
|
|
factory = AccessController.doPrivileged(
|
187 |
|
|
new PrivilegedAction<PreferencesFactory>() {
|
188 |
|
|
public PreferencesFactory run() {
|
189 |
|
|
PreferencesFactory pf = null;
|
190 |
|
|
String className = System.getProperty
|
191 |
|
|
("java.util.prefs.PreferencesFactory");
|
192 |
|
|
if (className != null) {
|
193 |
|
|
try {
|
194 |
|
|
Class fc = Class.forName(className);
|
195 |
|
|
Object o = fc.newInstance();
|
196 |
|
|
pf = (PreferencesFactory) o;
|
197 |
|
|
} catch (ClassNotFoundException cnfe)
|
198 |
|
|
{/*ignore*/}
|
199 |
|
|
catch (InstantiationException ie)
|
200 |
|
|
{/*ignore*/}
|
201 |
|
|
catch (IllegalAccessException iae)
|
202 |
|
|
{/*ignore*/}
|
203 |
|
|
catch (ClassCastException cce)
|
204 |
|
|
{/*ignore*/}
|
205 |
|
|
}
|
206 |
|
|
return pf;
|
207 |
|
|
}
|
208 |
|
|
});
|
209 |
|
|
|
210 |
|
|
// Still no factory? Try to see if we have one defined
|
211 |
|
|
// as a System Preference
|
212 |
|
|
if (factory == null)
|
213 |
|
|
{
|
214 |
|
|
Iterator iter = ServiceFactory.lookupProviders
|
215 |
|
|
(PreferencesFactory.class, null);
|
216 |
|
|
|
217 |
|
|
if (iter != null && iter.hasNext())
|
218 |
|
|
factory = (PreferencesFactory) iter.next();
|
219 |
|
|
}
|
220 |
|
|
|
221 |
|
|
// Still no factory? Use our default.
|
222 |
|
|
if (factory == null)
|
223 |
|
|
{
|
224 |
|
|
try
|
225 |
|
|
{
|
226 |
|
|
Class cls = Class.forName (defaultFactoryClass);
|
227 |
|
|
factory = (PreferencesFactory) cls.newInstance();
|
228 |
|
|
}
|
229 |
|
|
catch (Exception e)
|
230 |
|
|
{
|
231 |
|
|
throw new RuntimeException ("Couldn't load default factory"
|
232 |
|
|
+ " '"+ defaultFactoryClass +"'", e);
|
233 |
|
|
}
|
234 |
|
|
}
|
235 |
|
|
|
236 |
|
|
}
|
237 |
|
|
|
238 |
|
|
return factory;
|
239 |
|
|
}
|
240 |
|
|
|
241 |
|
|
/**
|
242 |
|
|
* Returns the system preferences node for the package of a class.
|
243 |
|
|
* The package node name of the class is determined by dropping the
|
244 |
|
|
* final component of the fully qualified class name and
|
245 |
|
|
* changing all '.' to '/' in the package name. If the class of the
|
246 |
|
|
* object has no package then the package node name is "<unnamed>".
|
247 |
|
|
* The returned node is <code>systemRoot().node(packageNodeName)</code>.
|
248 |
|
|
*
|
249 |
|
|
* @param c Object whose default system preference node is requested
|
250 |
|
|
* @returns system preferences node that should be used by class c
|
251 |
|
|
* @exception SecurityException when a security manager is installed and
|
252 |
|
|
* the caller does not have <code>RuntimePermission("preferences")</code>.
|
253 |
|
|
*/
|
254 |
|
|
public static Preferences systemNodeForPackage(Class<?> c)
|
255 |
|
|
throws SecurityException
|
256 |
|
|
{
|
257 |
|
|
return nodeForPackage(c, systemRoot());
|
258 |
|
|
}
|
259 |
|
|
|
260 |
|
|
/**
|
261 |
|
|
* Returns the user preferences node for the package of a class.
|
262 |
|
|
* The package node name of the class is determined by dropping the
|
263 |
|
|
* final component of the fully qualified class name and
|
264 |
|
|
* changing all '.' to '/' in the package name. If the class of the
|
265 |
|
|
* object has no package then the package node name is "<unnamed>".
|
266 |
|
|
* The returned node is <code>userRoot().node(packageNodeName)</code>.
|
267 |
|
|
*
|
268 |
|
|
* @param c Object whose default userpreference node is requested
|
269 |
|
|
* @returns userpreferences node that should be used by class c
|
270 |
|
|
* @exception SecurityException when a security manager is installed and
|
271 |
|
|
* the caller does not have <code>RuntimePermission("preferences")</code>.
|
272 |
|
|
*/
|
273 |
|
|
public static Preferences userNodeForPackage(Class<?> c)
|
274 |
|
|
throws SecurityException
|
275 |
|
|
{
|
276 |
|
|
return nodeForPackage(c, userRoot());
|
277 |
|
|
}
|
278 |
|
|
|
279 |
|
|
/**
|
280 |
|
|
* Private helper method for <code>systemNodeForPackage()</code> and
|
281 |
|
|
* <code>userNodeForPackage()</code>. Given the correct system or user
|
282 |
|
|
* root it returns the correct Preference node for the package node name
|
283 |
|
|
* of the given object.
|
284 |
|
|
*/
|
285 |
|
|
private static Preferences nodeForPackage(Class c, Preferences root) {
|
286 |
|
|
// Get the package path
|
287 |
|
|
String className = c.getName();
|
288 |
|
|
String packagePath;
|
289 |
|
|
int index = className.lastIndexOf('.');
|
290 |
|
|
if(index == -1) {
|
291 |
|
|
packagePath = "<unnamed>";
|
292 |
|
|
} else {
|
293 |
|
|
packagePath = className.substring(0,index).replace('.','/');
|
294 |
|
|
}
|
295 |
|
|
|
296 |
|
|
return root.node(packagePath);
|
297 |
|
|
}
|
298 |
|
|
|
299 |
|
|
/**
|
300 |
|
|
* Import preferences from the given input stream. This expects
|
301 |
|
|
* preferences to be represented in XML as emitted by
|
302 |
|
|
* {@link #exportNode(OutputStream)} and
|
303 |
|
|
* {@link #exportSubtree(OutputStream)}.
|
304 |
|
|
* @throws IOException if there is an error while reading
|
305 |
|
|
* @throws InvalidPreferencesFormatException if the XML is not properly
|
306 |
|
|
* formatted
|
307 |
|
|
*/
|
308 |
|
|
public static void importPreferences(InputStream is)
|
309 |
|
|
throws InvalidPreferencesFormatException,
|
310 |
|
|
IOException
|
311 |
|
|
{
|
312 |
|
|
PreferencesFactory factory = getFactory();
|
313 |
|
|
NodeReader reader = new NodeReader(is, factory);
|
314 |
|
|
reader.importPreferences();
|
315 |
|
|
}
|
316 |
|
|
|
317 |
|
|
// abstract methods (identification)
|
318 |
|
|
|
319 |
|
|
/**
|
320 |
|
|
* Returns the absolute path name of this preference node.
|
321 |
|
|
* The absolute path name of a node is the path name of its parent node
|
322 |
|
|
* plus a '/' plus its own name. If the node is the root node and has no
|
323 |
|
|
* parent then its name is "" and its absolute path name is "/".
|
324 |
|
|
*/
|
325 |
|
|
public abstract String absolutePath();
|
326 |
|
|
|
327 |
|
|
/**
|
328 |
|
|
* Returns true if this node comes from the user preferences tree, false
|
329 |
|
|
* if it comes from the system preferences tree.
|
330 |
|
|
*/
|
331 |
|
|
public abstract boolean isUserNode();
|
332 |
|
|
|
333 |
|
|
/**
|
334 |
|
|
* Returns the name of this preferences node. The name of the node cannot
|
335 |
|
|
* be null, can be mostly 80 characters and cannot contain any '/'
|
336 |
|
|
* characters. The root node has as name "".
|
337 |
|
|
*/
|
338 |
|
|
public abstract String name();
|
339 |
|
|
|
340 |
|
|
/**
|
341 |
|
|
* Returns the String given by
|
342 |
|
|
* <code>
|
343 |
|
|
* (isUserNode() ? "User":"System") + " Preference Node: " + absolutePath()
|
344 |
|
|
* </code>
|
345 |
|
|
*/
|
346 |
|
|
public abstract String toString();
|
347 |
|
|
|
348 |
|
|
// abstract methods (navigation)
|
349 |
|
|
|
350 |
|
|
/**
|
351 |
|
|
* Returns all the direct sub nodes of this preferences node.
|
352 |
|
|
* Needs access to the backing store to give a meaningfull answer.
|
353 |
|
|
*
|
354 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
355 |
|
|
* reached
|
356 |
|
|
* @exception IllegalStateException when this node has been removed
|
357 |
|
|
*/
|
358 |
|
|
public abstract String[] childrenNames() throws BackingStoreException;
|
359 |
|
|
|
360 |
|
|
/**
|
361 |
|
|
* Returns a sub node of this preferences node if the given path is
|
362 |
|
|
* relative (does not start with a '/') or a sub node of the root
|
363 |
|
|
* if the path is absolute (does start with a '/').
|
364 |
|
|
*
|
365 |
|
|
* @exception IllegalStateException if this node has been removed
|
366 |
|
|
* @exception IllegalArgumentException if the path contains two or more
|
367 |
|
|
* consecutive '/' characters, ends with a '/' charactor and is not the
|
368 |
|
|
* string "/" (indicating the root node) or any name on the path is more
|
369 |
|
|
* then 80 characters long
|
370 |
|
|
*/
|
371 |
|
|
public abstract Preferences node(String path);
|
372 |
|
|
|
373 |
|
|
/**
|
374 |
|
|
* Returns true if the node that the path points to exists in memory or
|
375 |
|
|
* in the backing store. Otherwise it returns false or an exception is
|
376 |
|
|
* thrown. When this node is removed the only valid parameter is the
|
377 |
|
|
* empty string (indicating this node), the return value in that case
|
378 |
|
|
* will be false.
|
379 |
|
|
*
|
380 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
381 |
|
|
* reached
|
382 |
|
|
* @exception IllegalStateException if this node has been removed
|
383 |
|
|
* and the path is not the empty string (indicating this node)
|
384 |
|
|
* @exception IllegalArgumentException if the path contains two or more
|
385 |
|
|
* consecutive '/' characters, ends with a '/' charactor and is not the
|
386 |
|
|
* string "/" (indicating the root node) or any name on the path is more
|
387 |
|
|
* then 80 characters long
|
388 |
|
|
*/
|
389 |
|
|
public abstract boolean nodeExists(String path)
|
390 |
|
|
throws BackingStoreException;
|
391 |
|
|
|
392 |
|
|
/**
|
393 |
|
|
* Returns the parent preferences node of this node or null if this is
|
394 |
|
|
* the root of the preferences tree.
|
395 |
|
|
*
|
396 |
|
|
* @exception IllegalStateException if this node has been removed
|
397 |
|
|
*/
|
398 |
|
|
public abstract Preferences parent();
|
399 |
|
|
|
400 |
|
|
// abstract methods (export)
|
401 |
|
|
|
402 |
|
|
/**
|
403 |
|
|
* Export this node, but not its descendants, as XML to the
|
404 |
|
|
* indicated output stream. The XML will be encoded using UTF-8
|
405 |
|
|
* and will use a specified document type:<br>
|
406 |
|
|
* <code><!DOCTYPE preferences SYSTEM "http://java.sun.com/dtd/preferences.dtd"></code><br>
|
407 |
|
|
* @param os the output stream to which the XML is sent
|
408 |
|
|
* @throws BackingStoreException if preference data cannot be read
|
409 |
|
|
* @throws IOException if an error occurs while writing the XML
|
410 |
|
|
* @throws IllegalStateException if this node or an ancestor has been removed
|
411 |
|
|
*/
|
412 |
|
|
public abstract void exportNode(OutputStream os)
|
413 |
|
|
throws BackingStoreException,
|
414 |
|
|
IOException;
|
415 |
|
|
|
416 |
|
|
/**
|
417 |
|
|
* Export this node and all its descendants as XML to the
|
418 |
|
|
* indicated output stream. The XML will be encoded using UTF-8
|
419 |
|
|
* and will use a specified document type:<br>
|
420 |
|
|
* <code><!DOCTYPE preferences SYSTEM "http://java.sun.com/dtd/preferences.dtd"></code><br>
|
421 |
|
|
* @param os the output stream to which the XML is sent
|
422 |
|
|
* @throws BackingStoreException if preference data cannot be read
|
423 |
|
|
* @throws IOException if an error occurs while writing the XML
|
424 |
|
|
* @throws IllegalStateException if this node or an ancestor has been removed
|
425 |
|
|
*/
|
426 |
|
|
public abstract void exportSubtree(OutputStream os)
|
427 |
|
|
throws BackingStoreException,
|
428 |
|
|
IOException;
|
429 |
|
|
|
430 |
|
|
// abstract methods (preference entry manipulation)
|
431 |
|
|
|
432 |
|
|
/**
|
433 |
|
|
* Returns an (possibly empty) array with all the keys of the preference
|
434 |
|
|
* entries of this node.
|
435 |
|
|
*
|
436 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
437 |
|
|
* reached
|
438 |
|
|
* @exception IllegalStateException if this node has been removed
|
439 |
|
|
*/
|
440 |
|
|
public abstract String[] keys() throws BackingStoreException;
|
441 |
|
|
|
442 |
|
|
/**
|
443 |
|
|
* Returns the value associated with the key in this preferences node. If
|
444 |
|
|
* the default value of the key cannot be found in the preferences node
|
445 |
|
|
* entries or something goes wrong with the backing store the supplied
|
446 |
|
|
* default value is returned.
|
447 |
|
|
*
|
448 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
449 |
|
|
* @exception IllegalStateException if this node has been removed
|
450 |
|
|
* @exception NullPointerException if key is null
|
451 |
|
|
*/
|
452 |
|
|
public abstract String get(String key, String defaultVal);
|
453 |
|
|
|
454 |
|
|
/**
|
455 |
|
|
* Convenience method for getting the given entry as a boolean.
|
456 |
|
|
* When the string representation of the requested entry is either
|
457 |
|
|
* "true" or "false" (ignoring case) then that value is returned,
|
458 |
|
|
* otherwise the given default boolean value is returned.
|
459 |
|
|
*
|
460 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
461 |
|
|
* @exception IllegalStateException if this node has been removed
|
462 |
|
|
* @exception NullPointerException if key is null
|
463 |
|
|
*/
|
464 |
|
|
public abstract boolean getBoolean(String key, boolean defaultVal);
|
465 |
|
|
|
466 |
|
|
/**
|
467 |
|
|
* Convenience method for getting the given entry as a byte array.
|
468 |
|
|
* When the string representation of the requested entry is a valid
|
469 |
|
|
* Base64 encoded string (without any other characters, such as newlines)
|
470 |
|
|
* then the decoded Base64 string is returned as byte array,
|
471 |
|
|
* otherwise the given default byte array value is returned.
|
472 |
|
|
*
|
473 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
474 |
|
|
* @exception IllegalStateException if this node has been removed
|
475 |
|
|
* @exception NullPointerException if key is null
|
476 |
|
|
*/
|
477 |
|
|
public abstract byte[] getByteArray(String key, byte[] defaultVal);
|
478 |
|
|
|
479 |
|
|
/**
|
480 |
|
|
* Convenience method for getting the given entry as a double.
|
481 |
|
|
* When the string representation of the requested entry can be decoded
|
482 |
|
|
* with <code>Double.parseDouble()</code> then that double is returned,
|
483 |
|
|
* otherwise the given default double value is returned.
|
484 |
|
|
*
|
485 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
486 |
|
|
* @exception IllegalStateException if this node has been removed
|
487 |
|
|
* @exception NullPointerException if key is null
|
488 |
|
|
*/
|
489 |
|
|
public abstract double getDouble(String key, double defaultVal);
|
490 |
|
|
|
491 |
|
|
/**
|
492 |
|
|
* Convenience method for getting the given entry as a float.
|
493 |
|
|
* When the string representation of the requested entry can be decoded
|
494 |
|
|
* with <code>Float.parseFloat()</code> then that float is returned,
|
495 |
|
|
* otherwise the given default float value is returned.
|
496 |
|
|
*
|
497 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
498 |
|
|
* @exception IllegalStateException if this node has been removed
|
499 |
|
|
* @exception NullPointerException if key is null
|
500 |
|
|
*/
|
501 |
|
|
public abstract float getFloat(String key, float defaultVal);
|
502 |
|
|
|
503 |
|
|
/**
|
504 |
|
|
* Convenience method for getting the given entry as an integer.
|
505 |
|
|
* When the string representation of the requested entry can be decoded
|
506 |
|
|
* with <code>Integer.parseInt()</code> then that integer is returned,
|
507 |
|
|
* otherwise the given default integer value is returned.
|
508 |
|
|
*
|
509 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
510 |
|
|
* @exception IllegalStateException if this node has been removed
|
511 |
|
|
* @exception NullPointerException if key is null
|
512 |
|
|
*/
|
513 |
|
|
public abstract int getInt(String key, int defaultVal);
|
514 |
|
|
|
515 |
|
|
/**
|
516 |
|
|
* Convenience method for getting the given entry as a long.
|
517 |
|
|
* When the string representation of the requested entry can be decoded
|
518 |
|
|
* with <code>Long.parseLong()</code> then that long is returned,
|
519 |
|
|
* otherwise the given default long value is returned.
|
520 |
|
|
*
|
521 |
|
|
* @exception IllegalArgumentException if key is larger then 80 characters
|
522 |
|
|
* @exception IllegalStateException if this node has been removed
|
523 |
|
|
* @exception NullPointerException if key is null
|
524 |
|
|
*/
|
525 |
|
|
public abstract long getLong(String key, long defaultVal);
|
526 |
|
|
|
527 |
|
|
/**
|
528 |
|
|
* Sets the value of the given preferences entry for this node.
|
529 |
|
|
* Key and value cannot be null, the key cannot exceed 80 characters
|
530 |
|
|
* and the value cannot exceed 8192 characters.
|
531 |
|
|
* <p>
|
532 |
|
|
* The result will be immediatly visible in this VM, but may not be
|
533 |
|
|
* immediatly written to the backing store.
|
534 |
|
|
*
|
535 |
|
|
* @exception NullPointerException if either key or value are null
|
536 |
|
|
* @exception IllegalArgumentException if either key or value are to large
|
537 |
|
|
* @exception IllegalStateException when this node has been removed
|
538 |
|
|
*/
|
539 |
|
|
public abstract void put(String key, String value);
|
540 |
|
|
|
541 |
|
|
/**
|
542 |
|
|
* Convenience method for setting the given entry as a boolean.
|
543 |
|
|
* The boolean is converted with <code>Boolean.toString(value)</code>
|
544 |
|
|
* and then stored in the preference entry as that string.
|
545 |
|
|
*
|
546 |
|
|
* @exception NullPointerException if key is null
|
547 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
548 |
|
|
* @exception IllegalStateException when this node has been removed
|
549 |
|
|
*/
|
550 |
|
|
public abstract void putBoolean(String key, boolean value);
|
551 |
|
|
|
552 |
|
|
/**
|
553 |
|
|
* Convenience method for setting the given entry as an array of bytes.
|
554 |
|
|
* The byte array is converted to a Base64 encoded string
|
555 |
|
|
* and then stored in the preference entry as that string.
|
556 |
|
|
* <p>
|
557 |
|
|
* Note that a byte array encoded as a Base64 string will be about 1.3
|
558 |
|
|
* times larger then the original length of the byte array, which means
|
559 |
|
|
* that the byte array may not be larger about 6 KB.
|
560 |
|
|
*
|
561 |
|
|
* @exception NullPointerException if either key or value are null
|
562 |
|
|
* @exception IllegalArgumentException if either key or value are to large
|
563 |
|
|
* @exception IllegalStateException when this node has been removed
|
564 |
|
|
*/
|
565 |
|
|
public abstract void putByteArray(String key, byte[] value);
|
566 |
|
|
|
567 |
|
|
/**
|
568 |
|
|
* Convenience method for setting the given entry as a double.
|
569 |
|
|
* The double is converted with <code>Double.toString(double)</code>
|
570 |
|
|
* and then stored in the preference entry as that string.
|
571 |
|
|
*
|
572 |
|
|
* @exception NullPointerException if the key is null
|
573 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
574 |
|
|
* @exception IllegalStateException when this node has been removed
|
575 |
|
|
*/
|
576 |
|
|
public abstract void putDouble(String key, double value);
|
577 |
|
|
|
578 |
|
|
/**
|
579 |
|
|
* Convenience method for setting the given entry as a float.
|
580 |
|
|
* The float is converted with <code>Float.toString(float)</code>
|
581 |
|
|
* and then stored in the preference entry as that string.
|
582 |
|
|
*
|
583 |
|
|
* @exception NullPointerException if the key is null
|
584 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
585 |
|
|
* @exception IllegalStateException when this node has been removed
|
586 |
|
|
*/
|
587 |
|
|
public abstract void putFloat(String key, float value);
|
588 |
|
|
|
589 |
|
|
/**
|
590 |
|
|
* Convenience method for setting the given entry as an integer.
|
591 |
|
|
* The integer is converted with <code>Integer.toString(int)</code>
|
592 |
|
|
* and then stored in the preference entry as that string.
|
593 |
|
|
*
|
594 |
|
|
* @exception NullPointerException if the key is null
|
595 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
596 |
|
|
* @exception IllegalStateException when this node has been removed
|
597 |
|
|
*/
|
598 |
|
|
public abstract void putInt(String key, int value);
|
599 |
|
|
|
600 |
|
|
/**
|
601 |
|
|
* Convenience method for setting the given entry as a long.
|
602 |
|
|
* The long is converted with <code>Long.toString(long)</code>
|
603 |
|
|
* and then stored in the preference entry as that string.
|
604 |
|
|
*
|
605 |
|
|
* @exception NullPointerException if the key is null
|
606 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
607 |
|
|
* @exception IllegalStateException when this node has been removed
|
608 |
|
|
*/
|
609 |
|
|
public abstract void putLong(String key, long value);
|
610 |
|
|
|
611 |
|
|
/**
|
612 |
|
|
* Removes the preferences entry from this preferences node.
|
613 |
|
|
* <p>
|
614 |
|
|
* The result will be immediatly visible in this VM, but may not be
|
615 |
|
|
* immediatly written to the backing store.
|
616 |
|
|
*
|
617 |
|
|
* @exception NullPointerException if the key is null
|
618 |
|
|
* @exception IllegalArgumentException if the key length is to large
|
619 |
|
|
* @exception IllegalStateException when this node has been removed
|
620 |
|
|
*/
|
621 |
|
|
public abstract void remove(String key);
|
622 |
|
|
|
623 |
|
|
// abstract methods (preference node manipulation)
|
624 |
|
|
|
625 |
|
|
/**
|
626 |
|
|
* Removes all entries from this preferences node. May need access to the
|
627 |
|
|
* backing store to get and clear all entries.
|
628 |
|
|
* <p>
|
629 |
|
|
* The result will be immediatly visible in this VM, but may not be
|
630 |
|
|
* immediatly written to the backing store.
|
631 |
|
|
*
|
632 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
633 |
|
|
* reached
|
634 |
|
|
* @exception IllegalStateException if this node has been removed
|
635 |
|
|
*/
|
636 |
|
|
public abstract void clear() throws BackingStoreException;
|
637 |
|
|
|
638 |
|
|
/**
|
639 |
|
|
* Writes all preference changes on this and any subnode that have not
|
640 |
|
|
* yet been written to the backing store. This has no effect on the
|
641 |
|
|
* preference entries in this VM, but it makes sure that all changes
|
642 |
|
|
* are visible to other programs (other VMs might need to call the
|
643 |
|
|
* <code>sync()</code> method to actually see the changes to the backing
|
644 |
|
|
* store.
|
645 |
|
|
*
|
646 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
647 |
|
|
* reached
|
648 |
|
|
* @exception IllegalStateException if this node has been removed
|
649 |
|
|
*/
|
650 |
|
|
public abstract void flush() throws BackingStoreException;
|
651 |
|
|
|
652 |
|
|
/**
|
653 |
|
|
* Writes and reads all preference changes to and from this and any
|
654 |
|
|
* subnodes. This makes sure that all local changes are written to the
|
655 |
|
|
* backing store and that all changes to the backing store are visible
|
656 |
|
|
* in this preference node (and all subnodes).
|
657 |
|
|
*
|
658 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
659 |
|
|
* reached
|
660 |
|
|
* @exception IllegalStateException if this node has been removed
|
661 |
|
|
*/
|
662 |
|
|
public abstract void sync() throws BackingStoreException;
|
663 |
|
|
|
664 |
|
|
/**
|
665 |
|
|
* Removes this and all subnodes from the backing store and clears all
|
666 |
|
|
* entries. After removal this instance will not be useable (except for
|
667 |
|
|
* a few methods that don't throw a <code>InvalidStateException</code>),
|
668 |
|
|
* even when a new node with the same path name is created this instance
|
669 |
|
|
* will not be usable again. The root (system or user) may never be removed.
|
670 |
|
|
* <p>
|
671 |
|
|
* Note that according to the specification an implementation may delay
|
672 |
|
|
* removal of the node from the backing store till the <code>flush()</code>
|
673 |
|
|
* method is called. But the <code>flush()</code> method may throw a
|
674 |
|
|
* <code>IllegalStateException</code> when the node has been removed.
|
675 |
|
|
* So most implementations will actually remove the node and any subnodes
|
676 |
|
|
* from the backing store immediatly.
|
677 |
|
|
*
|
678 |
|
|
* @exception BackingStoreException when the backing store cannot be
|
679 |
|
|
* reached
|
680 |
|
|
* @exception IllegalStateException if this node has already been removed
|
681 |
|
|
* @exception UnsupportedOperationException if this is a root node
|
682 |
|
|
*/
|
683 |
|
|
public abstract void removeNode() throws BackingStoreException;
|
684 |
|
|
|
685 |
|
|
// abstract methods (listeners)
|
686 |
|
|
|
687 |
|
|
public abstract void addNodeChangeListener(NodeChangeListener listener);
|
688 |
|
|
|
689 |
|
|
public abstract void addPreferenceChangeListener
|
690 |
|
|
(PreferenceChangeListener listener);
|
691 |
|
|
|
692 |
|
|
public abstract void removeNodeChangeListener(NodeChangeListener listener);
|
693 |
|
|
|
694 |
|
|
public abstract void removePreferenceChangeListener
|
695 |
|
|
(PreferenceChangeListener listener);
|
696 |
|
|
}
|