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 * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
28 *
29 * All rights reserved.
30 *
31 * Redistribution and use in source and binary forms, with or without
32 * modification, are permitted provided that the following conditions are met:
33 *
34 * * Redistributions of source code must retain the above copyright notice,
35 * this list of conditions and the following disclaimer.
36 *
37 * * Redistributions in binary form must reproduce the above copyright notice,
38 * this list of conditions and the following disclaimer in the documentation
39 * and/or other materials provided with the distribution.
40 *
41 * * Neither the name of JSR-310 nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
49 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
50 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
52 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
53 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
54 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
55 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57 package java.time;
58
59 import java.io.DataInput;
60 import java.io.DataOutput;
61 import java.io.IOException;
62 import java.io.InvalidObjectException;
63 import java.io.ObjectStreamException;
64 import java.io.Serializable;
65 import java.time.zone.ZoneRules;
66 import java.time.zone.ZoneRulesException;
67 import java.time.zone.ZoneRulesProvider;
68 import java.util.Objects;
69 import java.util.regex.Pattern;
70
71 /**
72 * A geographical region where the same time-zone rules apply.
73 * <p>
74 * Time-zone information is categorized as a set of rules defining when and
75 * how the offset from UTC/Greenwich changes. These rules are accessed using
76 * identifiers based on geographical regions, such as countries or states.
77 * The most common region classification is the Time Zone Database (TZDB),
78 * which defines regions such as 'Europe/Paris' and 'Asia/Tokyo'.
79 * <p>
80 * The region identifier, modeled by this class, is distinct from the
81 * underlying rules, modeled by {@link ZoneRules}.
82 * The rules are defined by governments and change frequently.
83 * By contrast, the region identifier is well-defined and long-lived.
84 * This separation also allows rules to be shared between regions if appropriate.
85 *
86 * <h3>Specification for implementors</h3>
87 * This class is immutable and thread-safe.
88 *
89 * @since 1.8
90 */
91 final class ZoneRegion extends ZoneId implements Serializable {
92
93 /**
94 * Serialization version.
95 */
96 private static final long serialVersionUID = 8386373296231747096L;
97 /**
98 * The regex pattern for region IDs.
99 */
100 private static final Pattern PATTERN = Pattern.compile("[A-Za-z][A-Za-z0-9~/._+-]+");
101
102 /**
103 * The time-zone ID, not null.
104 */
105 private final String id;
106 /**
107 * The time-zone rules, null if zone ID was loaded leniently.
108 */
109 private final transient ZoneRules rules;
110
111 /**
112 * Obtains an instance of {@code ZoneRegion} from an identifier without checking
113 * if the time-zone has available rules.
114 * <p>
115 * This method parses the ID and applies any appropriate normalization.
116 * It does not validate the ID against the known set of IDsfor which rules are available.
117 * <p>
118 * This method is intended for advanced use cases.
119 * For example, consider a system that always retrieves time-zone rules from a remote server.
120 * Using this factory would allow a {@code ZoneRegion}, and thus a {@code ZonedDateTime},
121 * to be created without loading the rules from the remote server.
122 *
123 * @param zoneId the time-zone ID, not null
124 * @return the zone ID, not null
125 * @throws DateTimeException if the ID format is invalid
126 */
127 private static ZoneRegion ofLenient(String zoneId) {
128 return ofId(zoneId, false);
129 }
130
131 /**
132 * Obtains an instance of {@code ZoneId} from an identifier.
133 *
134 * @param zoneId the time-zone ID, not null
135 * @param checkAvailable whether to check if the zone ID is available
136 * @return the zone ID, not null
137 * @throws DateTimeException if the ID format is invalid
138 * @throws DateTimeException if checking availability and the ID cannot be found
139 */
140 static ZoneRegion ofId(String zoneId, boolean checkAvailable) {
141 Objects.requireNonNull(zoneId, "zoneId");
142 if (zoneId.length() < 2 || zoneId.startsWith("UTC") ||
143 zoneId.startsWith("GMT") || (PATTERN.matcher(zoneId).matches() == false)) {
144 throw new DateTimeException("ZoneId format is not a valid region format");
145 }
146 ZoneRules rules = null;
147 try {
148 // always attempt load for better behavior after deserialization
149 rules = ZoneRulesProvider.getRules(zoneId);
150 } catch (ZoneRulesException ex) {
151 if (checkAvailable) {
152 throw ex;
153 }
154 }
155 return new ZoneRegion(zoneId, rules);
156 }
157
158 //-------------------------------------------------------------------------
159 /**
160 * Constructor.
161 *
162 * @param id the time-zone ID, not null
163 * @param rules the rules, null for lazy lookup
164 */
165 ZoneRegion(String id, ZoneRules rules) {
166 this.id = id;
167 this.rules = rules;
168 }
169
170 //-----------------------------------------------------------------------
171 @Override
172 public String getId() {
173 return id;
174 }
175
176 @Override
177 public ZoneRules getRules() {
178 // additional query for group provider when null allows for possibility
179 // that the provider was added after the ZoneId was created
180 return (rules != null ? rules : ZoneRulesProvider.getRules(id));
181 }
182
183 //-----------------------------------------------------------------------
184 /**
185 * Writes the object using a
186 * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
187 * <pre>
188 * out.writeByte(7); // identifies this as a ZoneId (not ZoneOffset)
189 * out.writeUTF(zoneId);
190 * </pre>
191 *
192 * @return the instance of {@code Ser}, not null
193 */
194 private Object writeReplace() {
195 return new Ser(Ser.ZONE_REGION_TYPE, this);
196 }
197
198 /**
199 * Defend against malicious streams.
200 * @return never
201 * @throws InvalidObjectException always
202 */
203 private Object readResolve() throws ObjectStreamException {
204 throw new InvalidObjectException("Deserialization via serialization delegate");
205 }
206
207 @Override
208 void write(DataOutput out) throws IOException {
209 out.writeByte(Ser.ZONE_REGION_TYPE);
210 writeExternal(out);
211 }
212
213 void writeExternal(DataOutput out) throws IOException {
214 out.writeUTF(id);
215 }
216
217 static ZoneId readExternal(DataInput in) throws IOException {
218 String id = in.readUTF();
219 return ofLenient(id);
220 }
221
222 }