1 /*
2 * Copyright (c) 2012, 2016, 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.time.DateTimeException;
69 import java.time.chrono.ChronoLocalDate;
70 import java.time.chrono.Chronology;
71 import java.time.format.ResolverStyle;
72 import java.util.Map;
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 * <p>
81 * The fields are implemented relative to {@link ChronoField#EPOCH_DAY EPOCH_DAY}.
82 * The fields are supported, and can be queried and set if {@code EPOCH_DAY} is available.
83 * The fields work with all chronologies.
84 *
85 * @implSpec
86 * This is an immutable and thread-safe class.
87 *
88 * @since 1.8
89 */
90 public final class JulianFields {
91
92 /**
93 * The offset from Julian to EPOCH DAY.
94 */
95 private static final long JULIAN_DAY_OFFSET = 2440588L;
96
97 /**
98 * Julian Day field.
99 * <p>
100 * This is an integer-based version of the Julian Day Number.
101 * Julian Day is a well-known system that represents the count of whole days since day 0,
102 * which is defined to be January 1, 4713 BCE in the Julian calendar, and -4713-11-24 Gregorian.
103 * The field has "JulianDay" as 'name', and 'DAYS' as 'baseUnit'.
104 * The field always refers to the local date-time, ignoring the offset or zone.
105 * <p>
106 * For date-times, 'JULIAN_DAY.getFrom()' assumes the same value from
107 * midnight until just before the next midnight.
108 * When 'JULIAN_DAY.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
109 * 'JULIAN_DAY.adjustInto()' and 'JULIAN_DAY.getFrom()' only apply to {@code Temporal} objects that
110 * can be converted into {@link ChronoField#EPOCH_DAY}.
111 * An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
112 * <p>
113 * In the resolving phase of parsing, a date can be created from a Julian Day field.
114 * In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
115 * the Julian Day value is validated against the range of valid values.
116 * In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
117 *
118 * <h3>Astronomical and Scientific Notes</h3>
119 * The standard astronomical definition uses a fraction to indicate the time-of-day,
120 * where each day is counted from midday to midday. For example,
121 * a fraction of 0 represents midday, a fraction of 0.25
122 * represents 18:00, a fraction of 0.5 represents midnight and a fraction
123 * of 0.75 represents 06:00.
124 * <p>
125 * By contrast, this implementation has no fractional part, and counts
126 * days from midnight to midnight.
127 * This implementation uses an integer and days starting at midnight.
128 * The integer value for the Julian Day Number is the astronomical Julian Day value at midday
129 * of the date in question.
130 * This amounts to the astronomical Julian Day, rounded to an integer {@code JDN = floor(JD + 0.5)}.
131 *
132 * <pre>
133 * | ISO date | Julian Day Number | Astronomical Julian Day |
134 * | 1970-01-01T00:00 | 2,440,588 | 2,440,587.5 |
135 * | 1970-01-01T06:00 | 2,440,588 | 2,440,587.75 |
136 * | 1970-01-01T12:00 | 2,440,588 | 2,440,588.0 |
137 * | 1970-01-01T18:00 | 2,440,588 | 2,440,588.25 |
138 * | 1970-01-02T00:00 | 2,440,589 | 2,440,588.5 |
139 * | 1970-01-02T06:00 | 2,440,589 | 2,440,588.75 |
140 * | 1970-01-02T12:00 | 2,440,589 | 2,440,589.0 |
141 * </pre>
142 * <p>
143 * Julian Days are sometimes taken to imply Universal Time or UTC, but this
144 * implementation always uses the Julian Day number for the local date,
145 * regardless of the offset or time-zone.
146 */
147 public static final TemporalField JULIAN_DAY = Field.JULIAN_DAY;
148
149 /**
150 * Modified Julian Day field.
151 * <p>
152 * This is an integer-based version of the Modified Julian Day Number.
153 * Modified Julian Day (MJD) is a well-known system that counts days continuously.
154 * It is defined relative to astronomical Julian Day as {@code MJD = JD - 2400000.5}.
155 * Each Modified Julian Day runs from midnight to midnight.
156 * The field always refers to the local date-time, ignoring the offset or zone.
157 * <p>
158 * For date-times, 'MODIFIED_JULIAN_DAY.getFrom()' assumes the same value from
159 * midnight until just before the next midnight.
160 * When 'MODIFIED_JULIAN_DAY.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
161 * 'MODIFIED_JULIAN_DAY.adjustInto()' and 'MODIFIED_JULIAN_DAY.getFrom()' only apply to {@code Temporal} objects
162 * that can be converted into {@link ChronoField#EPOCH_DAY}.
163 * An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
164 * <p>
165 * This implementation is an integer version of MJD with the decimal part rounded to floor.
166 * <p>
167 * In the resolving phase of parsing, a date can be created from a Modified Julian Day field.
168 * In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
169 * the Modified Julian Day value is validated against the range of valid values.
170 * In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
171 *
172 * <h3>Astronomical and Scientific Notes</h3>
173 * <pre>
174 * | ISO date | Modified Julian Day | Decimal MJD |
175 * | 1970-01-01T00:00 | 40,587 | 40,587.0 |
176 * | 1970-01-01T06:00 | 40,587 | 40,587.25 |
177 * | 1970-01-01T12:00 | 40,587 | 40,587.5 |
178 * | 1970-01-01T18:00 | 40,587 | 40,587.75 |
179 * | 1970-01-02T00:00 | 40,588 | 40,588.0 |
180 * | 1970-01-02T06:00 | 40,588 | 40,588.25 |
181 * | 1970-01-02T12:00 | 40,588 | 40,588.5 |
182 * </pre>
183 *
184 * Modified Julian Days are sometimes taken to imply Universal Time or UTC, but this
185 * implementation always uses the Modified Julian Day for the local date,
186 * regardless of the offset or time-zone.
187 */
188 public static final TemporalField MODIFIED_JULIAN_DAY = Field.MODIFIED_JULIAN_DAY;
189
190 /**
191 * Rata Die field.
192 * <p>
193 * Rata Die counts whole days continuously starting day 1 at midnight at the beginning of 0001-01-01 (ISO).
194 * The field always refers to the local date-time, ignoring the offset or zone.
195 * <p>
196 * For date-times, 'RATA_DIE.getFrom()' assumes the same value from
197 * midnight until just before the next midnight.
198 * When 'RATA_DIE.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
199 * 'RATA_DIE.adjustInto()' and 'RATA_DIE.getFrom()' only apply to {@code Temporal} objects
200 * that can be converted into {@link ChronoField#EPOCH_DAY}.
201 * An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
202 * <p>
203 * In the resolving phase of parsing, a date can be created from a Rata Die field.
204 * In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
205 * the Rata Die value is validated against the range of valid values.
206 * In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
207 */
208 public static final TemporalField RATA_DIE = Field.RATA_DIE;
209
210 /**
211 * Restricted constructor.
212 */
213 private JulianFields() {
214 throw new AssertionError("Not instantiable");
215 }
216
217 /**
218 * Implementation of JulianFields. Each instance is a singleton.
219 */
220 private static enum Field implements TemporalField {
221 JULIAN_DAY("JulianDay", DAYS, FOREVER, JULIAN_DAY_OFFSET),
222 MODIFIED_JULIAN_DAY("ModifiedJulianDay", DAYS, FOREVER, 40587L),
223 RATA_DIE("RataDie", DAYS, FOREVER, 719163L);
224
225 private static final long serialVersionUID = -7501623920830201812L;
226
227 private final transient String name;
228 private final transient TemporalUnit baseUnit;
229 private final transient TemporalUnit rangeUnit;
230 private final transient ValueRange range;
231 private final transient long offset;
232
233 private Field(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, long offset) {
234 this.name = name;
235 this.baseUnit = baseUnit;
236 this.rangeUnit = rangeUnit;
237 this.range = ValueRange.of(-365243219162L + offset, 365241780471L + offset);
238 this.offset = offset;
239 }
240
241 //-----------------------------------------------------------------------
242 @Override
243 public TemporalUnit getBaseUnit() {
244 return baseUnit;
245 }
246
247 @Override
248 public TemporalUnit getRangeUnit() {
249 return rangeUnit;
250 }
251
252 @Override
253 public boolean isDateBased() {
254 return true;
255 }
256
257 @Override
258 public boolean isTimeBased() {
259 return false;
260 }
261
262 @Override
263 public ValueRange range() {
264 return range;
265 }
266
267 //-----------------------------------------------------------------------
268 @Override
269 public boolean isSupportedBy(TemporalAccessor temporal) {
270 return temporal.isSupported(EPOCH_DAY);
271 }
272
273 @Override
274 public ValueRange rangeRefinedBy(TemporalAccessor temporal) {
275 if (isSupportedBy(temporal) == false) {
276 throw new DateTimeException("Unsupported field: " + this);
277 }
278 return range();
279 }
280
281 @Override
282 public long getFrom(TemporalAccessor temporal) {
283 return temporal.getLong(EPOCH_DAY) + offset;
284 }
285
286 @SuppressWarnings("unchecked")
287 @Override
288 public <R extends Temporal> R adjustInto(R temporal, long newValue) {
289 if (range().isValidValue(newValue) == false) {
290 throw new DateTimeException("Invalid value: " + name + " " + newValue);
291 }
292 return (R) temporal.with(EPOCH_DAY, Math.subtractExact(newValue, offset));
293 }
294
295 //-----------------------------------------------------------------------
296 @Override
297 public ChronoLocalDate resolve(
298 Map<TemporalField, Long> fieldValues, TemporalAccessor partialTemporal, ResolverStyle resolverStyle) {
299 long value = fieldValues.remove(this);
300 Chronology chrono = Chronology.from(partialTemporal);
301 if (resolverStyle == ResolverStyle.LENIENT) {
302 return chrono.dateEpochDay(Math.subtractExact(value, offset));
303 }
304 range().checkValidValue(value, this);
305 return chrono.dateEpochDay(value - offset);
306 }
307
308 //-----------------------------------------------------------------------
309 @Override
310 public String toString() {
311 return name;
312 }
313 }
314 }
315