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 package java.time.temporal;
63
64 import static java.time.temporal.ChronoField.EPOCH_DAY;
65 import static java.time.temporal.ChronoUnit.DAYS;
66 import static java.time.temporal.ChronoUnit.FOREVER;
67
68 import java.io.InvalidObjectException;
69 import java.io.Serializable;
70 import java.time.DateTimeException;
71 import java.time.LocalDate;
72 import java.time.format.DateTimeBuilder;
73
74 /**
75 * A set of date fields that provide access to Julian Days.
76 * <p>
77 * The Julian Day is a standard way of expressing date and time commonly used in the scientific community.
78 * It is expressed as a decimal number of whole days where days start at midday.
79 * This class represents variations on Julian Days that count whole days from midnight.
80 *
81 * <h3>Specification for implementors</h3>
82 * This is an immutable and thread-safe class.
83 *
84 * @since 1.8
85 */
86 public final class JulianFields {
87
88 /**
89 * The offset from Julian to EPOCH DAY.
90 */
91 private static final long JULIAN_DAY_OFFSET = 2440588L;
92
93 /**
94 * Julian Day field.
95 * <p>
96 * This is an integer-based version of the Julian Day Number.
97 * Julian Day is a well-known system that represents the count of whole days since day 0,
98 * which is defined to be January 1, 4713 BCE in the Julian calendar, and -4713-11-24 Gregorian.
99 * The field has "JulianDay" as 'name', and 'DAYS' as 'baseUnit'.
100 * The field always refers to the local date-time, ignoring the offset or zone.
101 * <p>
102 * For date-times, 'JULIAN_DAY.doGet()' assumes the same value from
103 * midnight until just before the next midnight.
104 * When 'JULIAN_DAY.doWith()' is applied to a date-time, the time of day portion remains unaltered.
105 * 'JULIAN_DAY.doWith()' and 'JULIAN_DAY.doGet()' only apply to {@code Temporal} objects that
106 * can be converted into {@link ChronoField#EPOCH_DAY}.
107 * A {@link DateTimeException} is thrown for any other type of object.
108 * <p>
109 * <h3>Astronomical and Scientific Notes</h3>
110 * The standard astronomical definition uses a fraction to indicate the time-of-day,
111 * thus 3.25 would represent the time 18:00, since days start at midday.
112 * This implementation uses an integer and days starting at midnight.
113 * The integer value for the Julian Day Number is the astronomical Julian Day value at midday
114 * of the date in question.
115 * This amounts to the astronomical Julian Day, rounded to an integer {@code JDN = floor(JD + 0.5)}.
116 * <p>
117 * <pre>
118 * | ISO date | Julian Day Number | Astronomical Julian Day |
119 * | 1970-01-01T00:00 | 2,440,588 | 2,440,587.5 |
120 * | 1970-01-01T06:00 | 2,440,588 | 2,440,587.75 |
121 * | 1970-01-01T12:00 | 2,440,588 | 2,440,588.0 |
122 * | 1970-01-01T18:00 | 2,440,588 | 2,440,588.25 |
123 * | 1970-01-02T00:00 | 2,440,589 | 2,440,588.5 |
124 * | 1970-01-02T06:00 | 2,440,589 | 2,440,588.75 |
125 * | 1970-01-02T12:00 | 2,440,589 | 2,440,589.0 |
126 * </pre>
127 * <p>
128 * Julian Days are sometimes taken to imply Universal Time or UTC, but this
129 * implementation always uses the Julian Day number for the local date,
130 * regardless of the offset or time-zone.
131 */
132 public static final TemporalField JULIAN_DAY = new Field("JulianDay", DAYS, FOREVER, JULIAN_DAY_OFFSET);
133
134 /**
135 * Modified Julian Day field.
136 * <p>
137 * This is an integer-based version of the Modified Julian Day Number.
138 * Modified Julian Day (MJD) is a well-known system that counts days continuously.
139 * It is defined relative to astronomical Julian Day as {@code MJD = JD - 2400000.5}.
140 * Each Modified Julian Day runs from midnight to midnight.
141 * The field always refers to the local date-time, ignoring the offset or zone.
142 * <p>
143 * For date-times, 'MODIFIED_JULIAN_DAY.doGet()' assumes the same value from
144 * midnight until just before the next midnight.
145 * When 'MODIFIED_JULIAN_DAY.doWith()' is applied to a date-time, the time of day portion remains unaltered.
146 * 'MODIFIED_JULIAN_DAY.doWith()' and 'MODIFIED_JULIAN_DAY.doGet()' only apply to {@code Temporal} objects
147 * that can be converted into {@link ChronoField#EPOCH_DAY}.
148 * A {@link DateTimeException} is thrown for any other type of object.
149 * <p>
150 * This implementation is an integer version of MJD with the decimal part rounded to floor.
151 * <p>
152 * <h3>Astronomical and Scientific Notes</h3>
153 * <pre>
154 * | ISO date | Modified Julian Day | Decimal MJD |
155 * | 1970-01-01T00:00 | 40,587 | 40,587.0 |
156 * | 1970-01-01T06:00 | 40,587 | 40,587.25 |
157 * | 1970-01-01T12:00 | 40,587 | 40,587.5 |
158 * | 1970-01-01T18:00 | 40,587 | 40,587.75 |
159 * | 1970-01-02T00:00 | 40,588 | 40,588.0 |
160 * | 1970-01-02T06:00 | 40,588 | 40,588.25 |
161 * | 1970-01-02T12:00 | 40,588 | 40,588.5 |
162 * </pre>
163 * <p>
164 * Modified Julian Days are sometimes taken to imply Universal Time or UTC, but this
165 * implementation always uses the Modified Julian Day for the local date,
166 * regardless of the offset or time-zone.
167 */
168 public static final TemporalField MODIFIED_JULIAN_DAY = new Field("ModifiedJulianDay", DAYS, FOREVER, 40587L);
169
170 /**
171 * Rata Die field.
172 * <p>
173 * Rata Die counts whole days continuously starting day 1 at midnight at the beginning of 0001-01-01 (ISO).
174 * The field always refers to the local date-time, ignoring the offset or zone.
175 * <p>
176 * For date-times, 'RATA_DIE.doGet()' assumes the same value from
177 * midnight until just before the next midnight.
178 * When 'RATA_DIE.doWith()' is applied to a date-time, the time of day portion remains unaltered.
179 * 'MODIFIED_JULIAN_DAY.doWith()' and 'RATA_DIE.doGet()' only apply to {@code Temporal} objects
180 * that can be converted into {@link ChronoField#EPOCH_DAY}.
181 * A {@link DateTimeException} is thrown for any other type of object.
182 */
183 public static final TemporalField RATA_DIE = new Field("RataDie", DAYS, FOREVER, 719163L);
184
185 /**
186 * Restricted constructor.
187 */
188 private JulianFields() {
189 throw new AssertionError("Not instantiable");
190 }
191
192 /**
193 * implementation of JulianFields. Each instance is a singleton.
194 */
195 private static class Field implements TemporalField, Serializable {
196
197 private static final long serialVersionUID = -7501623920830201812L;
198
199 private final String name;
200 private final transient TemporalUnit baseUnit;
201 private final transient TemporalUnit rangeUnit;
202 private final transient ValueRange range;
203 private final transient long offset;
204
205 private Field(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, long offset) {
206 this.name = name;
207 this.baseUnit = baseUnit;
208 this.rangeUnit = rangeUnit;
209 this.range = ValueRange.of(-365243219162L + offset, 365241780471L + offset);
210 this.offset = offset;
211 }
212
213
214 /**
215 * Resolve the object from the stream to the appropriate singleton.
216 * @return one of the singleton objects {@link #JULIAN_DAY},
217 * {@link #MODIFIED_JULIAN_DAY}, or {@link #RATA_DIE}.
218 * @throws InvalidObjectException if the object in the stream is not one of the singletons.
219 */
220 private Object readResolve() throws InvalidObjectException {
221 if (JULIAN_DAY.getName().equals(name)) {
222 return JULIAN_DAY;
223 } else if (MODIFIED_JULIAN_DAY.getName().equals(name)) {
224 return MODIFIED_JULIAN_DAY;
225 } else if (RATA_DIE.getName().equals(name)) {
226 return RATA_DIE;
227 } else {
228 throw new InvalidObjectException("Not one of the singletons");
229 }
230 }
231
232 //-----------------------------------------------------------------------
233 @Override
234 public String getName() {
235 return name;
236 }
237
238 @Override
239 public TemporalUnit getBaseUnit() {
240 return baseUnit;
241 }
242
243 @Override
244 public TemporalUnit getRangeUnit() {
245 return rangeUnit;
246 }
247
248 @Override
249 public ValueRange range() {
250 return range;
251 }
252
253 //-----------------------------------------------------------------------
254 @Override
255 public boolean doIsSupported(TemporalAccessor temporal) {
256 return temporal.isSupported(EPOCH_DAY);
257 }
258
259 @Override
260 public ValueRange doRange(TemporalAccessor temporal) {
261 if (doIsSupported(temporal) == false) {
262 throw new DateTimeException("Unsupported field: " + this);
263 }
264 return range();
265 }
266
267 @Override
268 public long doGet(TemporalAccessor temporal) {
269 return temporal.getLong(EPOCH_DAY) + offset;
270 }
271
272 @Override
273 public <R extends Temporal> R doWith(R temporal, long newValue) {
274 if (range().isValidValue(newValue) == false) {
275 throw new DateTimeException("Invalid value: " + name + " " + newValue);
276 }
277 return (R) temporal.with(EPOCH_DAY, Math.subtractExact(newValue, offset));
278 }
279
280 //-----------------------------------------------------------------------
281 @Override
282 public boolean resolve(DateTimeBuilder builder, long value) {
283 boolean changed = false;
284 changed = resolve0(JULIAN_DAY, builder, changed);
285 changed = resolve0(MODIFIED_JULIAN_DAY, builder, changed);
286 changed = resolve0(RATA_DIE, builder, changed);
287 return changed;
288 }
289
290 private boolean resolve0(TemporalField field, DateTimeBuilder builder, boolean changed) {
291 if (builder.containsFieldValue(field)) {
292 builder.addCalendrical(LocalDate.ofEpochDay(Math.subtractExact(builder.getFieldValue(JULIAN_DAY), JULIAN_DAY_OFFSET)));
293 builder.removeFieldValue(JULIAN_DAY);
294 changed = true;
295 }
296 return changed;
297 }
298
299 //-----------------------------------------------------------------------
300 @Override
301 public String toString() {
302 return getName();
303 }
304 }
305 }