J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2005 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.TimeZone; |
| 29 | |
| 30 | /** |
| 31 | * Julian calendar implementation. |
| 32 | * |
| 33 | * @author Masayoshi Okutsu |
| 34 | * @since 1.5 |
| 35 | */ |
| 36 | public class JulianCalendar extends BaseCalendar { |
| 37 | |
| 38 | private static final int BCE = 0; |
| 39 | private static final int CE = 1; |
| 40 | |
| 41 | private static final Era[] eras = { |
| 42 | new Era("BeforeCommonEra", "B.C.E.", Long.MIN_VALUE, false), |
| 43 | new Era("CommonEra", "C.E.", -62135709175808L, true) |
| 44 | }; |
| 45 | private static final int JULIAN_EPOCH = -1; |
| 46 | |
| 47 | private static class Date extends BaseCalendar.Date { |
| 48 | protected Date() { |
| 49 | super(); |
| 50 | setCache(1, -1L, 365); // January 1, 1 CE (Julian) |
| 51 | } |
| 52 | |
| 53 | protected Date(TimeZone zone) { |
| 54 | super(zone); |
| 55 | setCache(1, -1L, 365); // January 1, 1 CE (Julian) |
| 56 | } |
| 57 | |
| 58 | public Date setEra(Era era) { |
| 59 | if (era == null) { |
| 60 | throw new NullPointerException(); |
| 61 | } |
| 62 | if (era != eras[0] || era != eras[1]) { |
| 63 | throw new IllegalArgumentException("unknown era: " + era); |
| 64 | } |
| 65 | super.setEra(era); |
| 66 | return this; |
| 67 | } |
| 68 | |
| 69 | protected void setKnownEra(Era era) { |
| 70 | super.setEra(era); |
| 71 | } |
| 72 | |
| 73 | public int getNormalizedYear() { |
| 74 | if (getEra() == eras[BCE]) { |
| 75 | return 1 - getYear(); |
| 76 | } |
| 77 | return getYear(); |
| 78 | } |
| 79 | |
| 80 | // Use the year numbering ..., -2, -1, 0, 1, 2, ... for |
| 81 | // normalized years. This differs from "Calendrical |
| 82 | // Calculations" in which the numbering is ..., -2, -1, 1, 2, |
| 83 | // ... |
| 84 | public void setNormalizedYear(int year) { |
| 85 | if (year <= 0) { |
| 86 | setYear(1 - year); |
| 87 | setKnownEra(eras[BCE]); |
| 88 | } else { |
| 89 | setYear(year); |
| 90 | setKnownEra(eras[CE]); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | public String toString() { |
| 95 | String time = super.toString(); |
| 96 | time = time.substring(time.indexOf('T')); |
| 97 | StringBuffer sb = new StringBuffer(); |
| 98 | Era era = getEra(); |
| 99 | if (era != null) { |
| 100 | String n = era.getAbbreviation(); |
| 101 | if (n != null) { |
| 102 | sb.append(n).append(' '); |
| 103 | } |
| 104 | } |
| 105 | sb.append(getYear()).append('-'); |
| 106 | CalendarUtils.sprintf0d(sb, getMonth(), 2).append('-'); |
| 107 | CalendarUtils.sprintf0d(sb, getDayOfMonth(), 2); |
| 108 | sb.append(time); |
| 109 | return sb.toString(); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | JulianCalendar() { |
| 114 | setEras(eras); |
| 115 | } |
| 116 | |
| 117 | public String getName() { |
| 118 | return "julian"; |
| 119 | } |
| 120 | |
| 121 | public Date getCalendarDate() { |
| 122 | return getCalendarDate(System.currentTimeMillis(), newCalendarDate()); |
| 123 | } |
| 124 | |
| 125 | public Date getCalendarDate(long millis) { |
| 126 | return getCalendarDate(millis, newCalendarDate()); |
| 127 | } |
| 128 | |
| 129 | public Date getCalendarDate(long millis, CalendarDate date) { |
| 130 | return (Date) super.getCalendarDate(millis, date); |
| 131 | } |
| 132 | |
| 133 | public Date getCalendarDate(long millis, TimeZone zone) { |
| 134 | return getCalendarDate(millis, newCalendarDate(zone)); |
| 135 | } |
| 136 | |
| 137 | public Date newCalendarDate() { |
| 138 | return new Date(); |
| 139 | } |
| 140 | |
| 141 | public Date newCalendarDate(TimeZone zone) { |
| 142 | return new Date(zone); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * @param jyear normalized Julian year |
| 147 | */ |
| 148 | public long getFixedDate(int jyear, int month, int dayOfMonth, BaseCalendar.Date cache) { |
| 149 | boolean isJan1 = month == JANUARY && dayOfMonth == 1; |
| 150 | |
| 151 | // Look up the one year cache |
| 152 | if (cache != null && cache.hit(jyear)) { |
| 153 | if (isJan1) { |
| 154 | return cache.getCachedJan1(); |
| 155 | } |
| 156 | return cache.getCachedJan1() + getDayOfYear(jyear, month, dayOfMonth) - 1; |
| 157 | } |
| 158 | |
| 159 | long y = jyear; |
| 160 | long days = JULIAN_EPOCH - 1 + (365 * (y - 1)) + dayOfMonth; |
| 161 | if (y > 0) { |
| 162 | // CE years |
| 163 | days += (y - 1) / 4; |
| 164 | } else { |
| 165 | // BCE years |
| 166 | days += CalendarUtils.floorDivide(y - 1, 4); |
| 167 | } |
| 168 | if (month > 0) { |
| 169 | days += ((367 * (long) month) - 362) / 12; |
| 170 | } else { |
| 171 | days += CalendarUtils.floorDivide((367 * (long) month) - 362, 12); |
| 172 | } |
| 173 | if (month > FEBRUARY) { |
| 174 | days -= CalendarUtils.isJulianLeapYear(jyear) ? 1 : 2; |
| 175 | } |
| 176 | |
| 177 | // If it's January 1, update the cache. |
| 178 | if (cache != null && isJan1) { |
| 179 | cache.setCache(jyear, days, CalendarUtils.isJulianLeapYear(jyear) ? 366 : 365); |
| 180 | } |
| 181 | |
| 182 | return days; |
| 183 | } |
| 184 | |
| 185 | public void getCalendarDateFromFixedDate(CalendarDate date, long fixedDate) { |
| 186 | Date jdate = (Date) date; |
| 187 | long fd = 4 * (fixedDate - JULIAN_EPOCH) + 1464; |
| 188 | int year; |
| 189 | if (fd >= 0) { |
| 190 | year = (int)(fd / 1461); |
| 191 | } else { |
| 192 | year = (int) CalendarUtils.floorDivide(fd, 1461); |
| 193 | } |
| 194 | int priorDays = (int)(fixedDate - getFixedDate(year, JANUARY, 1, jdate)); |
| 195 | boolean isLeap = CalendarUtils.isJulianLeapYear(year); |
| 196 | if (fixedDate >= getFixedDate(year, MARCH, 1, jdate)) { |
| 197 | priorDays += isLeap ? 1 : 2; |
| 198 | } |
| 199 | int month = 12 * priorDays + 373; |
| 200 | if (month > 0) { |
| 201 | month /= 367; |
| 202 | } else { |
| 203 | month = CalendarUtils.floorDivide(month, 367); |
| 204 | } |
| 205 | int dayOfMonth = (int)(fixedDate - getFixedDate(year, month, 1, jdate)) + 1; |
| 206 | int dayOfWeek = getDayOfWeekFromFixedDate(fixedDate); |
| 207 | assert dayOfWeek > 0 : "negative day of week " + dayOfWeek; |
| 208 | jdate.setNormalizedYear(year); |
| 209 | jdate.setMonth(month); |
| 210 | jdate.setDayOfMonth(dayOfMonth); |
| 211 | jdate.setDayOfWeek(dayOfWeek); |
| 212 | jdate.setLeapYear(isLeap); |
| 213 | jdate.setNormalized(true); |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Returns the normalized Julian year number of the given fixed date. |
| 218 | */ |
| 219 | public int getYearFromFixedDate(long fixedDate) { |
| 220 | int year = (int) CalendarUtils.floorDivide(4 * (fixedDate - JULIAN_EPOCH) + 1464, 1461); |
| 221 | return year; |
| 222 | } |
| 223 | |
| 224 | public int getDayOfWeek(CalendarDate date) { |
| 225 | // TODO: should replace this with a faster calculation, such |
| 226 | // as cache table lookup |
| 227 | long fixedDate = getFixedDate(date); |
| 228 | return getDayOfWeekFromFixedDate(fixedDate); |
| 229 | } |
| 230 | |
| 231 | boolean isLeapYear(int jyear) { |
| 232 | return CalendarUtils.isJulianLeapYear(jyear); |
| 233 | } |
| 234 | } |