J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2005 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.lang.reflect.Field; |
| 29 | import java.util.HashMap; |
| 30 | import java.util.Locale; |
| 31 | import java.util.Map; |
| 32 | import java.util.MissingResourceException; |
| 33 | import java.util.ResourceBundle; |
| 34 | import java.util.Set; |
| 35 | import java.util.TimeZone; |
| 36 | import java.util.concurrent.ConcurrentHashMap; |
| 37 | import java.util.concurrent.ConcurrentMap; |
| 38 | |
| 39 | /** |
| 40 | * <code>CalendarSystem</code> is an abstract class that defines the |
| 41 | * programming interface to deal with calendar date and time. |
| 42 | * |
| 43 | * <p><code>CalendarSystem</code> instances are singletons. For |
| 44 | * example, there exists only one Gregorian calendar instance in the |
| 45 | * Java runtime environment. A singleton instance can be obtained |
| 46 | * calling one of the static factory methods. |
| 47 | * |
| 48 | * <h4>CalendarDate</h4> |
| 49 | * |
| 50 | * <p>For the methods in a <code>CalendarSystem</code> that manipulate |
| 51 | * a <code>CalendarDate</code>, <code>CalendarDate</code>s that have |
| 52 | * been created by the <code>CalendarSystem</code> must be |
| 53 | * specified. Otherwise, the methods throw an exception. This is |
| 54 | * because, for example, a Chinese calendar date can't be understood |
| 55 | * by the Hebrew calendar system. |
| 56 | * |
| 57 | * <h4>Calendar names</h4> |
| 58 | * |
| 59 | * Each calendar system has a unique name to be identified. The Java |
| 60 | * runtime in this release supports the following calendar systems. |
| 61 | * |
| 62 | * <pre> |
| 63 | * Name Calendar System |
| 64 | * --------------------------------------- |
| 65 | * gregorian Gregorian Calendar |
| 66 | * julian Julian Calendar |
| 67 | * japanese Japanese Imperial Calendar |
| 68 | * </pre> |
| 69 | * |
| 70 | * @see CalendarDate |
| 71 | * @author Masayoshi Okutsu |
| 72 | * @since 1.5 |
| 73 | */ |
| 74 | |
| 75 | public abstract class CalendarSystem { |
| 76 | |
| 77 | /////////////////////// Calendar Factory Methods ///////////////////////// |
| 78 | |
| 79 | private volatile static boolean initialized = false; |
| 80 | |
| 81 | // Map of calendar names and calendar class names |
| 82 | private static ConcurrentMap<String, String> names; |
| 83 | |
| 84 | // Map of calendar names and CalendarSystem instances |
| 85 | private static ConcurrentMap<String,CalendarSystem> calendars; |
| 86 | |
| 87 | private static final String PACKAGE_NAME = "sun.util.calendar."; |
| 88 | |
| 89 | private static final String[] namePairs = { |
| 90 | "gregorian", "Gregorian", |
| 91 | "japanese", "LocalGregorianCalendar", |
| 92 | "julian", "JulianCalendar", |
| 93 | /* |
| 94 | "hebrew", "HebrewCalendar", |
| 95 | "iso8601", "ISOCalendar", |
| 96 | "taiwanese", "LocalGregorianCalendar", |
| 97 | "thaibuddhist", "LocalGregorianCalendar", |
| 98 | */ |
| 99 | }; |
| 100 | |
| 101 | private static void initNames() { |
| 102 | ConcurrentMap<String,String> nameMap = new ConcurrentHashMap<String,String>(); |
| 103 | |
| 104 | // Associate a calendar name with its class name and the |
| 105 | // calendar class name with its date class name. |
| 106 | StringBuilder clName = new StringBuilder(); |
| 107 | for (int i = 0; i < namePairs.length; i += 2) { |
| 108 | clName.setLength(0); |
| 109 | String cl = clName.append(PACKAGE_NAME).append(namePairs[i+1]).toString(); |
| 110 | nameMap.put(namePairs[i], cl); |
| 111 | } |
| 112 | synchronized (CalendarSystem.class) { |
| 113 | if (!initialized) { |
| 114 | names = nameMap; |
| 115 | calendars = new ConcurrentHashMap<String,CalendarSystem>(); |
| 116 | initialized = true; |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | private final static Gregorian GREGORIAN_INSTANCE = new Gregorian(); |
| 122 | |
| 123 | /** |
| 124 | * Returns the singleton instance of the <code>Gregorian</code> |
| 125 | * calendar system. |
| 126 | * |
| 127 | * @return the <code>Gregorian</code> instance |
| 128 | */ |
| 129 | public static Gregorian getGregorianCalendar() { |
| 130 | return GREGORIAN_INSTANCE; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Returns a <code>CalendarSystem</code> specified by the calendar |
| 135 | * name. The calendar name has to be one of the supported calendar |
| 136 | * names. |
| 137 | * |
| 138 | * @param calendarName the calendar name |
| 139 | * @return the <code>CalendarSystem</code> specified by |
| 140 | * <code>calendarName</code>, or null if there is no |
| 141 | * <code>CalendarSystem</code> associated with the given calendar name. |
| 142 | */ |
| 143 | public static CalendarSystem forName(String calendarName) { |
| 144 | if ("gregorian".equals(calendarName)) { |
| 145 | return GREGORIAN_INSTANCE; |
| 146 | } |
| 147 | |
| 148 | if (!initialized) { |
| 149 | initNames(); |
| 150 | } |
| 151 | |
| 152 | CalendarSystem cal = calendars.get(calendarName); |
| 153 | if (cal != null) { |
| 154 | return cal; |
| 155 | } |
| 156 | |
| 157 | String className = names.get(calendarName); |
| 158 | if (className == null) { |
| 159 | return null; // Unknown calendar name |
| 160 | } |
| 161 | |
| 162 | if (className.endsWith("LocalGregorianCalendar")) { |
| 163 | // Create the specific kind of local Gregorian calendar system |
| 164 | cal = LocalGregorianCalendar.getLocalGregorianCalendar(calendarName); |
| 165 | } else { |
| 166 | try { |
| 167 | Class cl = Class.forName(className); |
| 168 | cal = (CalendarSystem) cl.newInstance(); |
| 169 | } catch (Exception e) { |
| 170 | throw new RuntimeException("internal error", e); |
| 171 | } |
| 172 | } |
| 173 | if (cal == null) { |
| 174 | return null; |
| 175 | } |
| 176 | CalendarSystem cs = calendars.putIfAbsent(calendarName, cal); |
| 177 | return (cs == null) ? cal : cs; |
| 178 | } |
| 179 | |
| 180 | //////////////////////////////// Calendar API ////////////////////////////////// |
| 181 | |
| 182 | /** |
| 183 | * Returns the name of this calendar system. |
| 184 | */ |
| 185 | public abstract String getName(); |
| 186 | |
| 187 | public abstract CalendarDate getCalendarDate(); |
| 188 | |
| 189 | /** |
| 190 | * Calculates calendar fields from the specified number of |
| 191 | * milliseconds since the Epoch, January 1, 1970 00:00:00 UTC |
| 192 | * (Gregorian). This method doesn't check overflow or underflow |
| 193 | * when adjusting the millisecond value (representing UTC) with |
| 194 | * the time zone offsets (i.e., the GMT offset and amount of |
| 195 | * daylight saving). |
| 196 | * |
| 197 | * @param millis the offset value in milliseconds from January 1, |
| 198 | * 1970 00:00:00 UTC (Gregorian). |
| 199 | * @return a <code>CalendarDate</code> instance that contains the |
| 200 | * calculated calendar field values. |
| 201 | */ |
| 202 | public abstract CalendarDate getCalendarDate(long millis); |
| 203 | |
| 204 | public abstract CalendarDate getCalendarDate(long millis, CalendarDate date); |
| 205 | |
| 206 | public abstract CalendarDate getCalendarDate(long millis, TimeZone zone); |
| 207 | |
| 208 | /** |
| 209 | * Constructs a <code>CalendarDate</code> that is specific to this |
| 210 | * calendar system. All calendar fields have their initial |
| 211 | * values. The {@link TimeZone#getDefault() default time zone} is |
| 212 | * set to the instance. |
| 213 | * |
| 214 | * @return a <code>CalendarDate</code> instance that contains the initial |
| 215 | * calendar field values. |
| 216 | */ |
| 217 | public abstract CalendarDate newCalendarDate(); |
| 218 | |
| 219 | public abstract CalendarDate newCalendarDate(TimeZone zone); |
| 220 | |
| 221 | /** |
| 222 | * Returns the number of milliseconds since the Epoch, January 1, |
| 223 | * 1970 00:00:00 UTC (Gregorian), represented by the specified |
| 224 | * <code>CalendarDate</code>. |
| 225 | * |
| 226 | * @param date the <code>CalendarDate</code> from which the time |
| 227 | * value is calculated |
| 228 | * @return the number of milliseconds since the Epoch. |
| 229 | */ |
| 230 | public abstract long getTime(CalendarDate date); |
| 231 | |
| 232 | /** |
| 233 | * Returns the length in days of the specified year by |
| 234 | * <code>date</code>. This method does not perform the |
| 235 | * normalization with the specified <code>CalendarDate</code>. The |
| 236 | * <code>CalendarDate</code> must be normalized to get a correct |
| 237 | * value. |
| 238 | */ |
| 239 | public abstract int getYearLength(CalendarDate date); |
| 240 | |
| 241 | /** |
| 242 | * Returns the number of months of the specified year. This method |
| 243 | * does not perform the normalization with the specified |
| 244 | * <code>CalendarDate</code>. The <code>CalendarDate</code> must |
| 245 | * be normalized to get a correct value. |
| 246 | */ |
| 247 | public abstract int getYearLengthInMonths(CalendarDate date); |
| 248 | |
| 249 | /** |
| 250 | * Returns the length in days of the month specified by the calendar |
| 251 | * date. This method does not perform the normalization with the |
| 252 | * specified calendar date. The <code>CalendarDate</code> must |
| 253 | * be normalized to get a correct value. |
| 254 | * |
| 255 | * @param date the date from which the month value is obtained |
| 256 | * @return the number of days in the month |
| 257 | * @exception IllegalArgumentException if the specified calendar date |
| 258 | * doesn't have a valid month value in this calendar system. |
| 259 | */ |
| 260 | public abstract int getMonthLength(CalendarDate date); // no setter |
| 261 | |
| 262 | /** |
| 263 | * Returns the length in days of a week in this calendar |
| 264 | * system. If this calendar system has multiple radix weeks, this |
| 265 | * method returns only one of them. |
| 266 | */ |
| 267 | public abstract int getWeekLength(); |
| 268 | |
| 269 | /** |
| 270 | * Returns the <code>Era</code> designated by the era name that |
| 271 | * has to be known to this calendar system. If no Era is |
| 272 | * applicable to this calendar system, null is returned. |
| 273 | * |
| 274 | * @param eraName the name of the era |
| 275 | * @return the <code>Era</code> designated by |
| 276 | * <code>eraName</code>, or <code>null</code> if no Era is |
| 277 | * applicable to this calendar system or the specified era name is |
| 278 | * not known to this calendar system. |
| 279 | */ |
| 280 | public abstract Era getEra(String eraName); |
| 281 | |
| 282 | /** |
| 283 | * Returns valid <code>Era</code>s of this calendar system. The |
| 284 | * return value is sorted in the descendant order. (i.e., the first |
| 285 | * element of the returned array is the oldest era.) If no era is |
| 286 | * applicable to this calendar system, <code>null</code> is returned. |
| 287 | * |
| 288 | * @return an array of valid <code>Era</code>s, or |
| 289 | * <code>null</code> if no era is applicable to this calendar |
| 290 | * system. |
| 291 | */ |
| 292 | public abstract Era[] getEras(); |
| 293 | |
| 294 | /** |
| 295 | * @throws IllegalArgumentException if the specified era name is |
| 296 | * unknown to this calendar system. |
| 297 | * @see Era |
| 298 | */ |
| 299 | public abstract void setEra(CalendarDate date, String eraName); |
| 300 | |
| 301 | /** |
| 302 | * Returns a <code>CalendarDate</code> of the n-th day of week |
| 303 | * which is on, after or before the specified date. For example, the |
| 304 | * first Sunday in April 2002 (Gregorian) can be obtained as |
| 305 | * below: |
| 306 | * |
| 307 | * <pre><code> |
| 308 | * Gregorian cal = CalendarSystem.getGregorianCalendar(); |
| 309 | * CalendarDate date = cal.newCalendarDate(); |
| 310 | * date.setDate(2004, cal.APRIL, 1); |
| 311 | * CalendarDate firstSun = cal.getNthDayOfWeek(1, cal.SUNDAY, date); |
| 312 | * // firstSun represents April 4, 2004. |
| 313 | * </code></pre> |
| 314 | * |
| 315 | * This method returns a new <code>CalendarDate</code> instance |
| 316 | * and doesn't modify the original date. |
| 317 | * |
| 318 | * @param nth specifies the n-th one. A positive number specifies |
| 319 | * <em>on or after</em> the <code>date</code>. A non-positive number |
| 320 | * specifies <em>on or before</em> the <code>date</code>. |
| 321 | * @param dayOfWeek the day of week |
| 322 | * @param date the date |
| 323 | * @return the date of the nth <code>dayOfWeek</code> after |
| 324 | * or before the specified <code>CalendarDate</code> |
| 325 | */ |
| 326 | public abstract CalendarDate getNthDayOfWeek(int nth, int dayOfWeek, |
| 327 | CalendarDate date); |
| 328 | |
| 329 | public abstract CalendarDate setTimeOfDay(CalendarDate date, int timeOfDay); |
| 330 | |
| 331 | /** |
| 332 | * Checks whether the calendar fields specified by <code>date</code> |
| 333 | * represents a valid date and time in this calendar system. If the |
| 334 | * given date is valid, <code>date</code> is marked as <em>normalized</em>. |
| 335 | * |
| 336 | * @param date the <code>CalendarDate</code> to be validated |
| 337 | * @return <code>true</code> if all the calendar fields are consistent, |
| 338 | * otherwise, <code>false</code> is returned. |
| 339 | * @exception NullPointerException if the specified |
| 340 | * <code>date</code> is <code>null</code> |
| 341 | */ |
| 342 | public abstract boolean validate(CalendarDate date); |
| 343 | |
| 344 | /** |
| 345 | * Normalizes calendar fields in the specified |
| 346 | * <code>date</code>. Also all {@link CalendarDate#FIELD_UNDEFINED |
| 347 | * undefined} fields are set to correct values. The actual |
| 348 | * normalization process is calendar system dependent. |
| 349 | * |
| 350 | * @param date the calendar date to be validated |
| 351 | * @return <code>true</code> if all fields have been normalized; |
| 352 | * <code>false</code> otherwise. |
| 353 | * @exception NullPointerException if the specified |
| 354 | * <code>date</code> is <code>null</code> |
| 355 | */ |
| 356 | public abstract boolean normalize(CalendarDate date); |
| 357 | } |