J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2004 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.util.calendar; |
| 27 | |
| 28 | import java.util.Locale; |
| 29 | import java.util.TimeZone; |
| 30 | |
| 31 | /** |
| 32 | * The <code>AbstractCalendar</code> class provides a framework for |
| 33 | * implementing a concrete calendar system. |
| 34 | * |
| 35 | * <p><a name="fixed_date"></a><B>Fixed Date</B><br> |
| 36 | * |
| 37 | * For implementing a concrete calendar system, each calendar must |
| 38 | * have the common date numbering, starting from midnight the onset of |
| 39 | * Monday, January 1, 1 (Gregorian). It is called a <I>fixed date</I> |
| 40 | * in this class. January 1, 1 (Gregorian) is fixed date 1. (See |
| 41 | * Nachum Dershowitz and Edward M. Reingold, <I>CALENDRICAL |
| 42 | * CALCULATION The Millennium Edition</I>, Section 1.2 for details.) |
| 43 | * |
| 44 | * @author Masayoshi Okutsu |
| 45 | * @since 1.5 |
| 46 | */ |
| 47 | |
| 48 | public abstract class AbstractCalendar extends CalendarSystem { |
| 49 | |
| 50 | // The constants assume no leap seconds support. |
| 51 | static final int SECOND_IN_MILLIS = 1000; |
| 52 | static final int MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60; |
| 53 | static final int HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60; |
| 54 | static final int DAY_IN_MILLIS = HOUR_IN_MILLIS * 24; |
| 55 | |
| 56 | // The number of days between January 1, 1 and January 1, 1970 (Gregorian) |
| 57 | static final int EPOCH_OFFSET = 719163; |
| 58 | |
| 59 | private Era[] eras; |
| 60 | |
| 61 | protected AbstractCalendar() { |
| 62 | } |
| 63 | |
| 64 | public Era getEra(String eraName) { |
| 65 | if (eras != null) { |
| 66 | for (int i = 0; i < eras.length; i++) { |
| 67 | if (eras[i].equals(eraName)) { |
| 68 | return eras[i]; |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | return null; |
| 73 | } |
| 74 | |
| 75 | public Era[] getEras() { |
| 76 | Era[] e = null; |
| 77 | if (eras != null) { |
| 78 | e = new Era[eras.length]; |
| 79 | System.arraycopy(eras, 0, e, 0, eras.length); |
| 80 | } |
| 81 | return e; |
| 82 | } |
| 83 | |
| 84 | public void setEra(CalendarDate date, String eraName) { |
| 85 | if (eras == null) { |
| 86 | return; // should report an error??? |
| 87 | } |
| 88 | for (int i = 0; i < eras.length; i++) { |
| 89 | Era e = eras[i]; |
| 90 | if (e != null && e.getName().equals(eraName)) { |
| 91 | date.setEra(e); |
| 92 | return; |
| 93 | } |
| 94 | } |
| 95 | throw new IllegalArgumentException("unknown era name: " + eraName); |
| 96 | } |
| 97 | |
| 98 | protected void setEras(Era[] eras) { |
| 99 | this.eras = eras; |
| 100 | } |
| 101 | |
| 102 | public CalendarDate getCalendarDate() { |
| 103 | return getCalendarDate(System.currentTimeMillis(), newCalendarDate()); |
| 104 | } |
| 105 | |
| 106 | public CalendarDate getCalendarDate(long millis) { |
| 107 | return getCalendarDate(millis, newCalendarDate()); |
| 108 | } |
| 109 | |
| 110 | public CalendarDate getCalendarDate(long millis, TimeZone zone) { |
| 111 | CalendarDate date = newCalendarDate(zone); |
| 112 | return getCalendarDate(millis, date); |
| 113 | } |
| 114 | |
| 115 | public CalendarDate getCalendarDate(long millis, CalendarDate date) { |
| 116 | int ms = 0; // time of day |
| 117 | int zoneOffset = 0; |
| 118 | int saving = 0; |
| 119 | long days = 0; // fixed date |
| 120 | |
| 121 | // adjust to local time if `date' has time zone. |
| 122 | TimeZone zi = date.getZone(); |
| 123 | if (zi != null) { |
| 124 | int[] offsets = new int[2]; |
| 125 | if (zi instanceof ZoneInfo) { |
| 126 | zoneOffset = ((ZoneInfo)zi).getOffsets(millis, offsets); |
| 127 | } else { |
| 128 | zoneOffset = zi.getOffset(millis); |
| 129 | offsets[0] = zi.getRawOffset(); |
| 130 | offsets[1] = zoneOffset - offsets[0]; |
| 131 | } |
| 132 | |
| 133 | // We need to calculate the given millis and time zone |
| 134 | // offset separately for java.util.GregorianCalendar |
| 135 | // compatibility. (i.e., millis + zoneOffset could cause |
| 136 | // overflow or underflow, which must be avoided.) Usually |
| 137 | // days should be 0 and ms is in the range of -13:00 to |
| 138 | // +14:00. However, we need to deal with extreme cases. |
| 139 | days = zoneOffset / DAY_IN_MILLIS; |
| 140 | ms = zoneOffset % DAY_IN_MILLIS; |
| 141 | saving = offsets[1]; |
| 142 | } |
| 143 | date.setZoneOffset(zoneOffset); |
| 144 | date.setDaylightSaving(saving); |
| 145 | |
| 146 | days += millis / DAY_IN_MILLIS; |
| 147 | ms += (int) (millis % DAY_IN_MILLIS); |
| 148 | if (ms >= DAY_IN_MILLIS) { |
| 149 | // at most ms is (DAY_IN_MILLIS - 1) * 2. |
| 150 | ms -= DAY_IN_MILLIS; |
| 151 | ++days; |
| 152 | } else { |
| 153 | // at most ms is (1 - DAY_IN_MILLIS) * 2. Adding one |
| 154 | // DAY_IN_MILLIS results in still negative. |
| 155 | while (ms < 0) { |
| 156 | ms += DAY_IN_MILLIS; |
| 157 | --days; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | // convert to fixed date (offset from Jan. 1, 1 (Gregorian)) |
| 162 | days += EPOCH_OFFSET; |
| 163 | |
| 164 | // calculate date fields from the fixed date |
| 165 | getCalendarDateFromFixedDate(date, days); |
| 166 | |
| 167 | // calculate time fields from the time of day |
| 168 | setTimeOfDay(date, ms); |
| 169 | date.setLeapYear(isLeapYear(date)); |
| 170 | date.setNormalized(true); |
| 171 | return date; |
| 172 | } |
| 173 | |
| 174 | public long getTime(CalendarDate date) { |
| 175 | long gd = getFixedDate(date); |
| 176 | long ms = (gd - EPOCH_OFFSET) * DAY_IN_MILLIS + getTimeOfDay(date); |
| 177 | int zoneOffset = 0; |
| 178 | TimeZone zi = date.getZone(); |
| 179 | if (zi != null) { |
| 180 | if (date.isNormalized()) { |
| 181 | return ms - date.getZoneOffset(); |
| 182 | } |
| 183 | // adjust time zone and daylight saving |
| 184 | int[] offsets = new int[2]; |
| 185 | if (date.isStandardTime()) { |
| 186 | // 1) 2:30am during starting-DST transition is |
| 187 | // intrepreted as 2:30am ST |
| 188 | // 2) 5:00pm during DST is still interpreted as 5:00pm ST |
| 189 | // 3) 1:30am during ending-DST transition is interpreted |
| 190 | // as 1:30am ST (after transition) |
| 191 | if (zi instanceof ZoneInfo) { |
| 192 | ((ZoneInfo)zi).getOffsetsByStandard(ms, offsets); |
| 193 | zoneOffset = offsets[0]; |
| 194 | } else { |
| 195 | zoneOffset = zi.getOffset(ms - zi.getRawOffset()); |
| 196 | } |
| 197 | } else { |
| 198 | // 1) 2:30am during starting-DST transition is |
| 199 | // intrepreted as 3:30am DT |
| 200 | // 2) 5:00pm during DST is intrepreted as 5:00pm DT |
| 201 | // 3) 1:30am during ending-DST transition is interpreted |
| 202 | // as 1:30am DT/0:30am ST (before transition) |
| 203 | if (zi instanceof ZoneInfo) { |
| 204 | zoneOffset = ((ZoneInfo)zi).getOffsetsByWall(ms, offsets); |
| 205 | } else { |
| 206 | zoneOffset = zi.getOffset(ms - zi.getRawOffset()); |
| 207 | } |
| 208 | } |
| 209 | } |
| 210 | ms -= zoneOffset; |
| 211 | getCalendarDate(ms, date); |
| 212 | return ms; |
| 213 | } |
| 214 | |
| 215 | protected long getTimeOfDay(CalendarDate date) { |
| 216 | long fraction = date.getTimeOfDay(); |
| 217 | if (fraction != CalendarDate.TIME_UNDEFINED) { |
| 218 | return fraction; |
| 219 | } |
| 220 | fraction = getTimeOfDayValue(date); |
| 221 | date.setTimeOfDay(fraction); |
| 222 | return fraction; |
| 223 | } |
| 224 | |
| 225 | public long getTimeOfDayValue(CalendarDate date) { |
| 226 | long fraction = date.getHours(); |
| 227 | fraction *= 60; |
| 228 | fraction += date.getMinutes(); |
| 229 | fraction *= 60; |
| 230 | fraction += date.getSeconds(); |
| 231 | fraction *= 1000; |
| 232 | fraction += date.getMillis(); |
| 233 | return fraction; |
| 234 | } |
| 235 | |
| 236 | public CalendarDate setTimeOfDay(CalendarDate cdate, int fraction) { |
| 237 | if (fraction < 0) { |
| 238 | throw new IllegalArgumentException(); |
| 239 | } |
| 240 | boolean normalizedState = cdate.isNormalized(); |
| 241 | int time = fraction; |
| 242 | int hours = time / HOUR_IN_MILLIS; |
| 243 | time %= HOUR_IN_MILLIS; |
| 244 | int minutes = time / MINUTE_IN_MILLIS; |
| 245 | time %= MINUTE_IN_MILLIS; |
| 246 | int seconds = time / SECOND_IN_MILLIS; |
| 247 | time %= SECOND_IN_MILLIS; |
| 248 | cdate.setHours(hours); |
| 249 | cdate.setMinutes(minutes); |
| 250 | cdate.setSeconds(seconds); |
| 251 | cdate.setMillis(time); |
| 252 | cdate.setTimeOfDay(fraction); |
| 253 | if (hours < 24 && normalizedState) { |
| 254 | // If this time of day setting doesn't affect the date, |
| 255 | // then restore the normalized state. |
| 256 | cdate.setNormalized(normalizedState); |
| 257 | } |
| 258 | return cdate; |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * Returns 7 in this default implementation. |
| 263 | * |
| 264 | * @return 7 |
| 265 | */ |
| 266 | public int getWeekLength() { |
| 267 | return 7; |
| 268 | } |
| 269 | |
| 270 | protected abstract boolean isLeapYear(CalendarDate date); |
| 271 | |
| 272 | public CalendarDate getNthDayOfWeek(int nth, int dayOfWeek, CalendarDate date) { |
| 273 | CalendarDate ndate = (CalendarDate) date.clone(); |
| 274 | normalize(ndate); |
| 275 | long fd = getFixedDate(ndate); |
| 276 | long nfd; |
| 277 | if (nth > 0) { |
| 278 | nfd = 7 * nth + getDayOfWeekDateBefore(fd, dayOfWeek); |
| 279 | } else { |
| 280 | nfd = 7 * nth + getDayOfWeekDateAfter(fd, dayOfWeek); |
| 281 | } |
| 282 | getCalendarDateFromFixedDate(ndate, nfd); |
| 283 | return ndate; |
| 284 | } |
| 285 | |
| 286 | /** |
| 287 | * Returns a date of the given day of week before the given fixed |
| 288 | * date. |
| 289 | * |
| 290 | * @param fixedDate the fixed date |
| 291 | * @param dayOfWeek the day of week |
| 292 | * @return the calculated date |
| 293 | */ |
| 294 | static long getDayOfWeekDateBefore(long fixedDate, int dayOfWeek) { |
| 295 | return getDayOfWeekDateOnOrBefore(fixedDate - 1, dayOfWeek); |
| 296 | } |
| 297 | |
| 298 | /** |
| 299 | * Returns a date of the given day of week that is closest to and |
| 300 | * after the given fixed date. |
| 301 | * |
| 302 | * @param fixedDate the fixed date |
| 303 | * @param dayOfWeek the day of week |
| 304 | * @return the calculated date |
| 305 | */ |
| 306 | static long getDayOfWeekDateAfter(long fixedDate, int dayOfWeek) { |
| 307 | return getDayOfWeekDateOnOrBefore(fixedDate + 7, dayOfWeek); |
| 308 | } |
| 309 | |
| 310 | /** |
| 311 | * Returns a date of the given day of week on or before the given fixed |
| 312 | * date. |
| 313 | * |
| 314 | * @param fixedDate the fixed date |
| 315 | * @param dayOfWeek the day of week |
| 316 | * @return the calculated date |
| 317 | */ |
| 318 | // public for java.util.GregorianCalendar |
| 319 | public static long getDayOfWeekDateOnOrBefore(long fixedDate, int dayOfWeek) { |
| 320 | long fd = fixedDate - (dayOfWeek - 1); |
| 321 | if (fd >= 0) { |
| 322 | return fixedDate - (fd % 7); |
| 323 | } |
| 324 | return fixedDate - CalendarUtils.mod(fd, 7); |
| 325 | } |
| 326 | |
| 327 | /** |
| 328 | * Returns the fixed date calculated with the specified calendar |
| 329 | * date. If the specified date is not normalized, its date fields |
| 330 | * are normalized. |
| 331 | * |
| 332 | * @param date a <code>CalendarDate</code> with which the fixed |
| 333 | * date is calculated |
| 334 | * @return the calculated fixed date |
| 335 | * @see AbstractCalendar.html#fixed_date |
| 336 | */ |
| 337 | protected abstract long getFixedDate(CalendarDate date); |
| 338 | |
| 339 | /** |
| 340 | * Calculates calendar fields from the specified fixed date. This |
| 341 | * method stores the calculated calendar field values in the specified |
| 342 | * <code>CalendarDate</code>. |
| 343 | * |
| 344 | * @param date a <code>CalendarDate</code> to stored the |
| 345 | * calculated calendar fields. |
| 346 | * @param fixedDate a fixed date to calculate calendar fields |
| 347 | * @see AbstractCalendar.html#fixed_date |
| 348 | */ |
| 349 | protected abstract void getCalendarDateFromFixedDate(CalendarDate date, |
| 350 | long fixedDate); |
| 351 | |
| 352 | public boolean validateTime(CalendarDate date) { |
| 353 | int t = date.getHours(); |
| 354 | if (t < 0 || t >= 24) { |
| 355 | return false; |
| 356 | } |
| 357 | t = date.getMinutes(); |
| 358 | if (t < 0 || t >= 60) { |
| 359 | return false; |
| 360 | } |
| 361 | t = date.getSeconds(); |
| 362 | // TODO: Leap second support. |
| 363 | if (t < 0 || t >= 60) { |
| 364 | return false; |
| 365 | } |
| 366 | t = date.getMillis(); |
| 367 | if (t < 0 || t >= 1000) { |
| 368 | return false; |
| 369 | } |
| 370 | return true; |
| 371 | } |
| 372 | |
| 373 | |
| 374 | int normalizeTime(CalendarDate date) { |
| 375 | long fraction = getTimeOfDay(date); |
| 376 | long days = 0; |
| 377 | |
| 378 | if (fraction >= DAY_IN_MILLIS) { |
| 379 | days = fraction / DAY_IN_MILLIS; |
| 380 | fraction %= DAY_IN_MILLIS; |
| 381 | } else if (fraction < 0) { |
| 382 | days = CalendarUtils.floorDivide(fraction, DAY_IN_MILLIS); |
| 383 | if (days != 0) { |
| 384 | fraction -= DAY_IN_MILLIS * days; // mod(fraction, DAY_IN_MILLIS) |
| 385 | } |
| 386 | } |
| 387 | if (days != 0) { |
| 388 | date.setTimeOfDay(fraction); |
| 389 | } |
| 390 | date.setMillis((int)(fraction % 1000)); |
| 391 | fraction /= 1000; |
| 392 | date.setSeconds((int)(fraction % 60)); |
| 393 | fraction /= 60; |
| 394 | date.setMinutes((int)(fraction % 60)); |
| 395 | date.setHours((int)(fraction / 60)); |
| 396 | return (int)days; |
| 397 | } |
| 398 | } |