15289
|
1 |
/*
|
|
2 |
* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
|
|
3 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
4 |
*
|
|
5 |
* This code is free software; you can redistribute it and/or modify it
|
|
6 |
* under the terms of the GNU General Public License version 2 only, as
|
|
7 |
* published by the Free Software Foundation. Oracle designates this
|
|
8 |
* particular file as subject to the "Classpath" exception as provided
|
|
9 |
* by Oracle in the LICENSE file that accompanied this code.
|
|
10 |
*
|
|
11 |
* This code is distributed in the hope that it will be useful, but WITHOUT
|
|
12 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
13 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
14 |
* version 2 for more details (a copy is included in the LICENSE file that
|
|
15 |
* accompanied this code).
|
|
16 |
*
|
|
17 |
* You should have received a copy of the GNU General Public License version
|
|
18 |
* 2 along with this work; if not, write to the Free Software Foundation,
|
|
19 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
20 |
*
|
|
21 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
22 |
* or visit www.oracle.com if you need additional information or have any
|
|
23 |
* questions.
|
|
24 |
*/
|
|
25 |
|
|
26 |
/*
|
|
27 |
* This file is available under and governed by the GNU General Public
|
|
28 |
* License version 2 only, as published by the Free Software Foundation.
|
|
29 |
* However, the following notice accompanied the original version of this
|
|
30 |
* file:
|
|
31 |
*
|
|
32 |
* Copyright (c) 2009-2012, Stephen Colebourne & Michael Nascimento Santos
|
|
33 |
*
|
|
34 |
* All rights reserved.
|
|
35 |
*
|
|
36 |
* Redistribution and use in source and binary forms, with or without
|
|
37 |
* modification, are permitted provided that the following conditions are met:
|
|
38 |
*
|
|
39 |
* * Redistributions of source code must retain the above copyright notice,
|
|
40 |
* this list of conditions and the following disclaimer.
|
|
41 |
*
|
|
42 |
* * Redistributions in binary form must reproduce the above copyright notice,
|
|
43 |
* this list of conditions and the following disclaimer in the documentation
|
|
44 |
* and/or other materials provided with the distribution.
|
|
45 |
*
|
|
46 |
* * Neither the name of JSR-310 nor the names of its contributors
|
|
47 |
* may be used to endorse or promote products derived from this software
|
|
48 |
* without specific prior written permission.
|
|
49 |
*
|
|
50 |
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
51 |
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
52 |
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
53 |
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
|
|
54 |
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
55 |
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
56 |
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
57 |
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
58 |
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
59 |
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
60 |
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
61 |
*/
|
|
62 |
package java.time.zone;
|
|
63 |
|
15658
|
64 |
import java.security.AccessController;
|
|
65 |
import java.security.PrivilegedAction;
|
15289
|
66 |
import java.time.ZoneId;
|
|
67 |
import java.time.ZonedDateTime;
|
|
68 |
import java.util.ArrayList;
|
|
69 |
import java.util.HashSet;
|
|
70 |
import java.util.Iterator;
|
|
71 |
import java.util.List;
|
|
72 |
import java.util.NavigableMap;
|
|
73 |
import java.util.Objects;
|
|
74 |
import java.util.ServiceConfigurationError;
|
|
75 |
import java.util.ServiceLoader;
|
|
76 |
import java.util.Set;
|
|
77 |
import java.util.concurrent.ConcurrentHashMap;
|
|
78 |
import java.util.concurrent.ConcurrentMap;
|
|
79 |
import java.util.concurrent.CopyOnWriteArrayList;
|
|
80 |
|
|
81 |
/**
|
|
82 |
* Provider of time-zone rules to the system.
|
|
83 |
* <p>
|
|
84 |
* This class manages the configuration of time-zone rules.
|
|
85 |
* The static methods provide the public API that can be used to manage the providers.
|
|
86 |
* The abstract methods provide the SPI that allows rules to be provided.
|
|
87 |
* <p>
|
15658
|
88 |
* ZoneRulesProvider may be installed in an instance of the Java Platform as
|
|
89 |
* extension classes, that is, jar files placed into any of the usual extension
|
|
90 |
* directories. Installed providers are loaded using the service-provider loading
|
|
91 |
* facility defined by the {@link ServiceLoader} class. A ZoneRulesProvider
|
|
92 |
* identifies itself with a provider configuration file named
|
|
93 |
* {@code java.time.zone.ZoneRulesProvider} in the resource directory
|
|
94 |
* {@code META-INF/services}. The file should contain a line that specifies the
|
|
95 |
* fully qualified concrete zonerules-provider class name.
|
|
96 |
* Providers may also be made available by adding them to the class path or by
|
|
97 |
* registering themselves via {@link #registerProvider} method.
|
|
98 |
* <p>
|
|
99 |
* The Java virtual machine has a default provider that provides zone rules
|
|
100 |
* for the time-zones defined by IANA Time Zone Database (TZDB). If the system
|
|
101 |
* property {@code java.time.zone.DefaultZoneRulesProvider} is defined then
|
|
102 |
* it is taken to be the fully-qualified name of a concrete ZoneRulesProvider
|
|
103 |
* class to be loaded as the default provider, using the system class loader.
|
|
104 |
* If this system property is not defined, a system-default provider will be
|
|
105 |
* loaded to serve as the default provider.
|
|
106 |
* <p>
|
15289
|
107 |
* Rules are looked up primarily by zone ID, as used by {@link ZoneId}.
|
|
108 |
* Only zone region IDs may be used, zone offset IDs are not used here.
|
|
109 |
* <p>
|
|
110 |
* Time-zone rules are political, thus the data can change at any time.
|
|
111 |
* Each provider will provide the latest rules for each zone ID, but they
|
|
112 |
* may also provide the history of how the rules changed.
|
|
113 |
*
|
|
114 |
* <h3>Specification for implementors</h3>
|
|
115 |
* This interface is a service provider that can be called by multiple threads.
|
|
116 |
* Implementations must be immutable and thread-safe.
|
|
117 |
* <p>
|
|
118 |
* Providers must ensure that once a rule has been seen by the application, the
|
|
119 |
* rule must continue to be available.
|
|
120 |
* <p>
|
15658
|
121 |
* Providers are encouraged to implement a meaningful {@code toString} method.
|
|
122 |
* <p>
|
15289
|
123 |
* Many systems would like to update time-zone rules dynamically without stopping the JVM.
|
|
124 |
* When examined in detail, this is a complex problem.
|
|
125 |
* Providers may choose to handle dynamic updates, however the default provider does not.
|
|
126 |
*
|
|
127 |
* @since 1.8
|
|
128 |
*/
|
|
129 |
public abstract class ZoneRulesProvider {
|
|
130 |
|
|
131 |
/**
|
|
132 |
* The set of loaded providers.
|
|
133 |
*/
|
|
134 |
private static final CopyOnWriteArrayList<ZoneRulesProvider> PROVIDERS = new CopyOnWriteArrayList<>();
|
|
135 |
/**
|
15658
|
136 |
* The lookup from zone ID to provider.
|
15289
|
137 |
*/
|
|
138 |
private static final ConcurrentMap<String, ZoneRulesProvider> ZONES = new ConcurrentHashMap<>(512, 0.75f, 2);
|
15658
|
139 |
|
15289
|
140 |
static {
|
15658
|
141 |
// if the property java.time.zone.DefaultZoneRulesProvider is
|
|
142 |
// set then its value is the class name of the default provider
|
|
143 |
final List<ZoneRulesProvider> loaded = new ArrayList<>();
|
|
144 |
AccessController.doPrivileged(new PrivilegedAction() {
|
|
145 |
public Object run() {
|
|
146 |
String prop = System.getProperty("java.time.zone.DefaultZoneRulesProvider");
|
|
147 |
if (prop != null) {
|
|
148 |
try {
|
|
149 |
Class<?> c = Class.forName(prop, true, ClassLoader.getSystemClassLoader());
|
|
150 |
ZoneRulesProvider provider = ZoneRulesProvider.class.cast(c.newInstance());
|
|
151 |
registerProvider(provider);
|
|
152 |
loaded.add(provider);
|
|
153 |
} catch (Exception x) {
|
|
154 |
throw new Error(x);
|
|
155 |
}
|
|
156 |
} else {
|
|
157 |
registerProvider(new TzdbZoneRulesProvider());
|
|
158 |
}
|
|
159 |
return null;
|
|
160 |
}
|
|
161 |
});
|
|
162 |
|
15289
|
163 |
ServiceLoader<ZoneRulesProvider> sl = ServiceLoader.load(ZoneRulesProvider.class, ClassLoader.getSystemClassLoader());
|
|
164 |
Iterator<ZoneRulesProvider> it = sl.iterator();
|
|
165 |
while (it.hasNext()) {
|
|
166 |
ZoneRulesProvider provider;
|
|
167 |
try {
|
|
168 |
provider = it.next();
|
|
169 |
} catch (ServiceConfigurationError ex) {
|
|
170 |
if (ex.getCause() instanceof SecurityException) {
|
|
171 |
continue; // ignore the security exception, try the next provider
|
|
172 |
}
|
|
173 |
throw ex;
|
|
174 |
}
|
15658
|
175 |
boolean found = false;
|
|
176 |
for (ZoneRulesProvider p : loaded) {
|
|
177 |
if (p.getClass() == provider.getClass()) {
|
|
178 |
found = true;
|
|
179 |
}
|
|
180 |
}
|
|
181 |
if (!found) {
|
|
182 |
registerProvider0(provider);
|
|
183 |
loaded.add(provider);
|
|
184 |
}
|
15289
|
185 |
}
|
|
186 |
// CopyOnWriteList could be slow if lots of providers and each added individually
|
|
187 |
PROVIDERS.addAll(loaded);
|
|
188 |
}
|
|
189 |
|
|
190 |
//-------------------------------------------------------------------------
|
|
191 |
/**
|
|
192 |
* Gets the set of available zone IDs.
|
|
193 |
* <p>
|
15658
|
194 |
* These IDs are the string form of a {@link ZoneId}.
|
15289
|
195 |
*
|
|
196 |
* @return a modifiable copy of the set of zone IDs, not null
|
|
197 |
*/
|
|
198 |
public static Set<String> getAvailableZoneIds() {
|
|
199 |
return new HashSet<>(ZONES.keySet());
|
|
200 |
}
|
|
201 |
|
|
202 |
/**
|
|
203 |
* Gets the rules for the zone ID.
|
|
204 |
* <p>
|
|
205 |
* This returns the latest available rules for the zone ID.
|
|
206 |
* <p>
|
|
207 |
* This method relies on time-zone data provider files that are configured.
|
|
208 |
* These are loaded using a {@code ServiceLoader}.
|
15658
|
209 |
* <p>
|
|
210 |
* The caching flag is designed to allow provider implementations to
|
|
211 |
* prevent the rules being cached in {@code ZoneId}.
|
|
212 |
* Under normal circumstances, the caching of zone rules is highly desirable
|
|
213 |
* as it will provide greater performance. However, there is a use case where
|
|
214 |
* the caching would not be desirable, see {@link #provideRules}.
|
15289
|
215 |
*
|
15658
|
216 |
* @param zoneId the zone ID as defined by {@code ZoneId}, not null
|
|
217 |
* @param forCaching whether the rules are being queried for caching,
|
|
218 |
* true if the returned rules will be cached by {@code ZoneId},
|
|
219 |
* false if they will be returned to the user without being cached in {@code ZoneId}
|
|
220 |
* @return the rules, null if {@code forCaching} is true and this
|
|
221 |
* is a dynamic provider that wants to prevent caching in {@code ZoneId},
|
|
222 |
* otherwise not null
|
|
223 |
* @throws ZoneRulesException if rules cannot be obtained for the zone ID
|
15289
|
224 |
*/
|
15658
|
225 |
public static ZoneRules getRules(String zoneId, boolean forCaching) {
|
15289
|
226 |
Objects.requireNonNull(zoneId, "zoneId");
|
15658
|
227 |
return getProvider(zoneId).provideRules(zoneId, forCaching);
|
15289
|
228 |
}
|
|
229 |
|
|
230 |
/**
|
|
231 |
* Gets the history of rules for the zone ID.
|
|
232 |
* <p>
|
|
233 |
* Time-zones are defined by governments and change frequently.
|
|
234 |
* This method allows applications to find the history of changes to the
|
|
235 |
* rules for a single zone ID. The map is keyed by a string, which is the
|
|
236 |
* version string associated with the rules.
|
|
237 |
* <p>
|
|
238 |
* The exact meaning and format of the version is provider specific.
|
|
239 |
* The version must follow lexicographical order, thus the returned map will
|
|
240 |
* be order from the oldest known rules to the newest available rules.
|
|
241 |
* The default 'TZDB' group uses version numbering consisting of the year
|
|
242 |
* followed by a letter, such as '2009e' or '2012f'.
|
|
243 |
* <p>
|
|
244 |
* Implementations must provide a result for each valid zone ID, however
|
|
245 |
* they do not have to provide a history of rules.
|
|
246 |
* Thus the map will always contain one element, and will only contain more
|
|
247 |
* than one element if historical rule information is available.
|
|
248 |
*
|
15658
|
249 |
* @param zoneId the zone ID as defined by {@code ZoneId}, not null
|
15289
|
250 |
* @return a modifiable copy of the history of the rules for the ID, sorted
|
|
251 |
* from oldest to newest, not null
|
15658
|
252 |
* @throws ZoneRulesException if history cannot be obtained for the zone ID
|
15289
|
253 |
*/
|
|
254 |
public static NavigableMap<String, ZoneRules> getVersions(String zoneId) {
|
|
255 |
Objects.requireNonNull(zoneId, "zoneId");
|
|
256 |
return getProvider(zoneId).provideVersions(zoneId);
|
|
257 |
}
|
|
258 |
|
|
259 |
/**
|
|
260 |
* Gets the provider for the zone ID.
|
|
261 |
*
|
15658
|
262 |
* @param zoneId the zone ID as defined by {@code ZoneId}, not null
|
15289
|
263 |
* @return the provider, not null
|
|
264 |
* @throws ZoneRulesException if the zone ID is unknown
|
|
265 |
*/
|
|
266 |
private static ZoneRulesProvider getProvider(String zoneId) {
|
|
267 |
ZoneRulesProvider provider = ZONES.get(zoneId);
|
|
268 |
if (provider == null) {
|
|
269 |
if (ZONES.isEmpty()) {
|
|
270 |
throw new ZoneRulesException("No time-zone data files registered");
|
|
271 |
}
|
|
272 |
throw new ZoneRulesException("Unknown time-zone ID: " + zoneId);
|
|
273 |
}
|
|
274 |
return provider;
|
|
275 |
}
|
|
276 |
|
|
277 |
//-------------------------------------------------------------------------
|
|
278 |
/**
|
|
279 |
* Registers a zone rules provider.
|
|
280 |
* <p>
|
|
281 |
* This adds a new provider to those currently available.
|
|
282 |
* A provider supplies rules for one or more zone IDs.
|
|
283 |
* A provider cannot be registered if it supplies a zone ID that has already been
|
|
284 |
* registered. See the notes on time-zone IDs in {@link ZoneId}, especially
|
|
285 |
* the section on using the concept of a "group" to make IDs unique.
|
|
286 |
* <p>
|
|
287 |
* To ensure the integrity of time-zones already created, there is no way
|
|
288 |
* to deregister providers.
|
|
289 |
*
|
|
290 |
* @param provider the provider to register, not null
|
15658
|
291 |
* @throws ZoneRulesException if a zone ID is already registered
|
15289
|
292 |
*/
|
|
293 |
public static void registerProvider(ZoneRulesProvider provider) {
|
|
294 |
Objects.requireNonNull(provider, "provider");
|
|
295 |
registerProvider0(provider);
|
|
296 |
PROVIDERS.add(provider);
|
|
297 |
}
|
|
298 |
|
|
299 |
/**
|
|
300 |
* Registers the provider.
|
|
301 |
*
|
|
302 |
* @param provider the provider to register, not null
|
|
303 |
* @throws ZoneRulesException if unable to complete the registration
|
|
304 |
*/
|
|
305 |
private static void registerProvider0(ZoneRulesProvider provider) {
|
|
306 |
for (String zoneId : provider.provideZoneIds()) {
|
|
307 |
Objects.requireNonNull(zoneId, "zoneId");
|
15658
|
308 |
ZoneRulesProvider old = ZONES.putIfAbsent(zoneId, provider);
|
15289
|
309 |
if (old != null) {
|
|
310 |
throw new ZoneRulesException(
|
|
311 |
"Unable to register zone as one already registered with that ID: " + zoneId +
|
|
312 |
", currently loading from provider: " + provider);
|
|
313 |
}
|
|
314 |
}
|
|
315 |
}
|
|
316 |
|
|
317 |
/**
|
|
318 |
* Refreshes the rules from the underlying data provider.
|
|
319 |
* <p>
|
15658
|
320 |
* This method allows an application to request that the providers check
|
|
321 |
* for any updates to the provided rules.
|
15289
|
322 |
* After calling this method, the offset stored in any {@link ZonedDateTime}
|
|
323 |
* may be invalid for the zone ID.
|
|
324 |
* <p>
|
15658
|
325 |
* Dynamic update of rules is a complex problem and most applications
|
|
326 |
* should not use this method or dynamic rules.
|
|
327 |
* To achieve dynamic rules, a provider implementation will have to be written
|
|
328 |
* as per the specification of this class.
|
|
329 |
* In addition, instances of {@code ZoneRules} must not be cached in the
|
|
330 |
* application as they will become stale. However, the boolean flag on
|
|
331 |
* {@link #provideRules(String, boolean)} allows provider implementations
|
|
332 |
* to control the caching of {@code ZoneId}, potentially ensuring that
|
|
333 |
* all objects in the system see the new rules.
|
|
334 |
* Note that there is likely to be a cost in performance of a dynamic rules
|
|
335 |
* provider. Note also that no dynamic rules provider is in this specification.
|
15289
|
336 |
*
|
|
337 |
* @return true if the rules were updated
|
|
338 |
* @throws ZoneRulesException if an error occurs during the refresh
|
|
339 |
*/
|
|
340 |
public static boolean refresh() {
|
|
341 |
boolean changed = false;
|
|
342 |
for (ZoneRulesProvider provider : PROVIDERS) {
|
|
343 |
changed |= provider.provideRefresh();
|
|
344 |
}
|
|
345 |
return changed;
|
|
346 |
}
|
|
347 |
|
|
348 |
/**
|
|
349 |
* Constructor.
|
|
350 |
*/
|
|
351 |
protected ZoneRulesProvider() {
|
|
352 |
}
|
|
353 |
|
|
354 |
//-----------------------------------------------------------------------
|
|
355 |
/**
|
|
356 |
* SPI method to get the available zone IDs.
|
|
357 |
* <p>
|
|
358 |
* This obtains the IDs that this {@code ZoneRulesProvider} provides.
|
15658
|
359 |
* A provider should provide data for at least one zone ID.
|
15289
|
360 |
* <p>
|
15658
|
361 |
* The returned zone IDs remain available and valid for the lifetime of the application.
|
|
362 |
* A dynamic provider may increase the set of IDs as more data becomes available.
|
15289
|
363 |
*
|
15658
|
364 |
* @return the set of zone IDs being provided, not null
|
|
365 |
* @throws ZoneRulesException if a problem occurs while providing the IDs
|
15289
|
366 |
*/
|
|
367 |
protected abstract Set<String> provideZoneIds();
|
|
368 |
|
|
369 |
/**
|
|
370 |
* SPI method to get the rules for the zone ID.
|
|
371 |
* <p>
|
15658
|
372 |
* This loads the rules for the specified zone ID.
|
|
373 |
* The provider implementation must validate that the zone ID is valid and
|
|
374 |
* available, throwing a {@code ZoneRulesException} if it is not.
|
|
375 |
* The result of the method in the valid case depends on the caching flag.
|
|
376 |
* <p>
|
|
377 |
* If the provider implementation is not dynamic, then the result of the
|
|
378 |
* method must be the non-null set of rules selected by the ID.
|
|
379 |
* <p>
|
|
380 |
* If the provider implementation is dynamic, then the flag gives the option
|
|
381 |
* of preventing the returned rules from being cached in {@link ZoneId}.
|
|
382 |
* When the flag is true, the provider is permitted to return null, where
|
|
383 |
* null will prevent the rules from being cached in {@code ZoneId}.
|
|
384 |
* When the flag is false, the provider must return non-null rules.
|
15289
|
385 |
*
|
15658
|
386 |
* @param zoneId the zone ID as defined by {@code ZoneId}, not null
|
|
387 |
* @param forCaching whether the rules are being queried for caching,
|
|
388 |
* true if the returned rules will be cached by {@code ZoneId},
|
|
389 |
* false if they will be returned to the user without being cached in {@code ZoneId}
|
|
390 |
* @return the rules, null if {@code forCaching} is true and this
|
|
391 |
* is a dynamic provider that wants to prevent caching in {@code ZoneId},
|
|
392 |
* otherwise not null
|
|
393 |
* @throws ZoneRulesException if rules cannot be obtained for the zone ID
|
15289
|
394 |
*/
|
15658
|
395 |
protected abstract ZoneRules provideRules(String zoneId, boolean forCaching);
|
15289
|
396 |
|
|
397 |
/**
|
|
398 |
* SPI method to get the history of rules for the zone ID.
|
|
399 |
* <p>
|
|
400 |
* This returns a map of historical rules keyed by a version string.
|
|
401 |
* The exact meaning and format of the version is provider specific.
|
|
402 |
* The version must follow lexicographical order, thus the returned map will
|
|
403 |
* be order from the oldest known rules to the newest available rules.
|
|
404 |
* The default 'TZDB' group uses version numbering consisting of the year
|
|
405 |
* followed by a letter, such as '2009e' or '2012f'.
|
|
406 |
* <p>
|
|
407 |
* Implementations must provide a result for each valid zone ID, however
|
|
408 |
* they do not have to provide a history of rules.
|
15658
|
409 |
* Thus the map will contain at least one element, and will only contain
|
|
410 |
* more than one element if historical rule information is available.
|
15289
|
411 |
* <p>
|
|
412 |
* The returned versions remain available and valid for the lifetime of the application.
|
|
413 |
* A dynamic provider may increase the set of versions as more data becomes available.
|
|
414 |
*
|
15658
|
415 |
* @param zoneId the zone ID as defined by {@code ZoneId}, not null
|
15289
|
416 |
* @return a modifiable copy of the history of the rules for the ID, sorted
|
|
417 |
* from oldest to newest, not null
|
15658
|
418 |
* @throws ZoneRulesException if history cannot be obtained for the zone ID
|
15289
|
419 |
*/
|
|
420 |
protected abstract NavigableMap<String, ZoneRules> provideVersions(String zoneId);
|
|
421 |
|
|
422 |
/**
|
|
423 |
* SPI method to refresh the rules from the underlying data provider.
|
|
424 |
* <p>
|
|
425 |
* This method provides the opportunity for a provider to dynamically
|
|
426 |
* recheck the underlying data provider to find the latest rules.
|
|
427 |
* This could be used to load new rules without stopping the JVM.
|
|
428 |
* Dynamic behavior is entirely optional and most providers do not support it.
|
|
429 |
* <p>
|
|
430 |
* This implementation returns false.
|
|
431 |
*
|
|
432 |
* @return true if the rules were updated
|
15658
|
433 |
* @throws ZoneRulesException if an error occurs during the refresh
|
15289
|
434 |
*/
|
|
435 |
protected boolean provideRefresh() {
|
|
436 |
return false;
|
|
437 |
}
|
|
438 |
|
|
439 |
}
|