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) 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
63 /**
64 * <p>
65 * Generic API for calendar systems other than the default ISO.
66 * </p>
67 * <p>
68 * The main API is based around the calendar system defined in ISO-8601.
69 * However, there are other calendar systems, and this package provides basic support for them.
70 * The alternate calendars are provided in the {@link java.time.chrono} package.
71 * </p>
72 * <p>
73 * A calendar system is defined by the {@link java.time.chrono.Chronology} interface,
74 * while a date in a calendar system is defined by the {@link java.time.chrono.ChronoLocalDate} interface.
75 * </p>
76 * <p>
77 * It is intended that applications use the main API whenever possible, including code to read and write
78 * from a persistent data store, such as a database, and to send dates and times across a network.
79 * The "chrono" classes are then used at the user interface level to deal with localized input/output.
80 * See {@link java.time.chrono.ChronoLocalDate ChronoLocalDate}
81 * for a full discussion of the issues.
82 * </p>
83 * <p>
84 * Using non-ISO calendar systems in an application introduces significant extra complexity.
85 * Ensure that the warnings and recommendations in {@code ChronoLocalDate} have been read before
86 * working with the "chrono" interfaces.
87 * </p>
88 * <p>
89 * The supported calendar systems includes:
90 * </p>
91 * <ul>
92 * <li>{@link java.time.chrono.HijrahChronology Hijrah calendar}</li>
93 * <li>{@link java.time.chrono.JapaneseChronology Japanese calendar}</li>
94 * <li>{@link java.time.chrono.MinguoChronology Minguo calendar}</li>
95 * <li>{@link java.time.chrono.ThaiBuddhistChronology Thai Buddhist calendar}</li>
96 * </ul>
97 *
98 * <h3>Example</h3>
99 * <p>
100 * This example lists todays date for all of the available calendars.
101 * </p>
102 * <pre>
103 * // Enumerate the list of available calendars and print todays date for each.
104 * Set<Chronology> chronos = Chronology.getAvailableChronologies();
105 * for (Chronology chrono : chronos) {
106 * ChronoLocalDate date = chrono.dateNow();
107 * System.out.printf(" %20s: %s%n", chrono.getId(), date.toString());
108 * }
109 * </pre>
110 *
111 * <p>
112 * This example creates and uses a date in a named non-ISO calendar system.
113 * </p>
114 * <pre>
115 * // Print the Thai Buddhist date
116 * ChronoLocalDate now1 = Chronology.of("ThaiBuddhist").dateNow();
117 * int day = now1.get(ChronoField.DAY_OF_MONTH);
118 * int dow = now1.get(ChronoField.DAY_OF_WEEK);
119 * int month = now1.get(ChronoField.MONTH_OF_YEAR);
120 * int year = now1.get(ChronoField.YEAR);
121 * System.out.printf(" Today is %s %s %d-%s-%d%n", now1.getChronology().getId(),
122 * dow, day, month, year);
123 * // Print today's date and the last day of the year for the Thai Buddhist Calendar.
124 * ChronoLocalDate first = now1
125 * .with(ChronoField.DAY_OF_MONTH, 1)
126 * .with(ChronoField.MONTH_OF_YEAR, 1);
127 * ChronoLocalDate last = first
128 * .plus(1, ChronoUnit.YEARS)
129 * .minus(1, ChronoUnit.DAYS);
130 * System.out.printf(" %s: 1st of year: %s; end of year: %s%n", last.getChronology().getId(),
131 * first, last);
132 * </pre>
133 *
134 * <p>
135 * This example creates and uses a date in a specific ThaiBuddhist calendar system.
136 * </p>
137 * <pre>
138 * // Print the Thai Buddhist date
139 * ThaiBuddhistDate now1 = ThaiBuddhistDate.now();
140 * int day = now1.get(ChronoField.DAY_OF_MONTH);
141 * int dow = now1.get(ChronoField.DAY_OF_WEEK);
142 * int month = now1.get(ChronoField.MONTH_OF_YEAR);
143 * int year = now1.get(ChronoField.YEAR);
144 * System.out.printf(" Today is %s %s %d-%s-%d%n", now1.getChronology().getId(),
145 * dow, day, month, year);
146 *
147 * // Print today's date and the last day of the year for the Thai Buddhist Calendar.
148 * ThaiBuddhistDate first = now1
149 * .with(ChronoField.DAY_OF_MONTH, 1)
150 * .with(ChronoField.MONTH_OF_YEAR, 1);
151 * ThaiBuddhistDate last = first
152 * .plus(1, ChronoUnit.YEARS)
153 * .minus(1, ChronoUnit.DAYS);
154 * System.out.printf(" %s: 1st of year: %s; end of year: %s%n", last.getChronology().getId(),
155 * first, last);
156 * </pre>
157 *
158 * <h3>Package specification</h3>
159 * <p>
160 * Unless otherwise noted, passing a null argument to a constructor or method in any class or interface
161 * in this package will cause a {@link java.lang.NullPointerException NullPointerException} to be thrown.
162 * The Javadoc "@param" definition is used to summarise the null-behavior.
163 * The "@throws {@link java.lang.NullPointerException}" is not explicitly documented in each method.
164 * </p>
165 * <p>
166 * All calculations should check for numeric overflow and throw either an {@link java.lang.ArithmeticException}
167 * or a {@link java.time.DateTimeException}.
168 * </p>
169 * @since JDK1.8
170 */
171 package java.time.chrono;