| 1 | /* |
| 2 | * Copyright 2001-2005 Stephen Colebourne |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.joda.time.chrono; |
| 17 | |
| 18 | import org.joda.time.DateTimeConstants; |
| 19 | import org.joda.time.DateTimeFieldType; |
| 20 | import org.joda.time.DateTimeUtils; |
| 21 | import org.joda.time.DurationField; |
| 22 | import org.joda.time.ReadablePartial; |
| 23 | import org.joda.time.field.FieldUtils; |
| 24 | import org.joda.time.field.ImpreciseDateTimeField; |
| 25 | |
| 26 | /** |
| 27 | * Provides time calculations for the month of the year component of time. |
| 28 | * |
| 29 | * @author Guy Allard |
| 30 | * @author Stephen Colebourne |
| 31 | * @author Brian S O'Neill |
| 32 | * @since 1.2, refactored from GJMonthOfYearDateTimeField |
| 33 | */ |
| 34 | class BasicMonthOfYearDateTimeField extends ImpreciseDateTimeField { |
| 35 | |
| 36 | /** Serialization version */ |
| 37 | private static final long serialVersionUID = -8258715387168736L; |
| 38 | |
| 39 | private static final int MIN = DateTimeConstants.JANUARY; |
| 40 | |
| 41 | private final BasicChronology iChronology; |
| 42 | private final int iMax; |
| 43 | private final int iLeapMonth; |
| 44 | |
| 45 | /** |
| 46 | * Restricted constructor. |
| 47 | * |
| 48 | * @param leapMonth the month of year that leaps |
| 49 | */ |
| 50 | BasicMonthOfYearDateTimeField(BasicChronology chronology, int leapMonth) { |
| 51 | super(DateTimeFieldType.monthOfYear(), chronology.getAverageMillisPerMonth()); |
| 52 | iChronology = chronology; |
| 53 | iMax = iChronology.getMaxMonth(); |
| 54 | iLeapMonth = leapMonth; |
| 55 | } |
| 56 | |
| 57 | //----------------------------------------------------------------------- |
| 58 | public boolean isLenient() { |
| 59 | return false; |
| 60 | } |
| 61 | |
| 62 | //----------------------------------------------------------------------- |
| 63 | /** |
| 64 | * Get the Month component of the specified time instant. |
| 65 | * |
| 66 | * @see org.joda.time.DateTimeField#get(long) |
| 67 | * @see org.joda.time.ReadableDateTime#getMonthOfYear() |
| 68 | * @param instant the time instant in millis to query. |
| 69 | * @return the month extracted from the input. |
| 70 | */ |
| 71 | public int get(long instant) { |
| 72 | return iChronology.getMonthOfYear(instant); |
| 73 | } |
| 74 | |
| 75 | //----------------------------------------------------------------------- |
| 76 | /** |
| 77 | * Add the specified month to the specified time instant. |
| 78 | * The amount added may be negative.<p> |
| 79 | * If the new month has less total days than the specified |
| 80 | * day of the month, this value is coerced to the nearest |
| 81 | * sane value. e.g.<p> |
| 82 | * 07-31 - (1 month) = 06-30<p> |
| 83 | * 03-31 - (1 month) = 02-28 or 02-29 depending<p> |
| 84 | * |
| 85 | * @see org.joda.time.DateTimeField#add |
| 86 | * @see org.joda.time.ReadWritableDateTime#addMonths(int) |
| 87 | * @param instant the time instant in millis to update. |
| 88 | * @param months the months to add (can be negative). |
| 89 | * @return the updated time instant. |
| 90 | */ |
| 91 | public long add(long instant, int months) { |
| 92 | if (months == 0) { |
| 93 | return instant; // the easy case |
| 94 | } |
| 95 | // |
| 96 | // Save time part first. |
| 97 | // |
| 98 | long timePart = iChronology.getMillisOfDay(instant); |
| 99 | // |
| 100 | // |
| 101 | // Get this year and month. |
| 102 | // |
| 103 | int thisYear = iChronology.getYear(instant); |
| 104 | int thisMonth = iChronology.getMonthOfYear(instant, thisYear); |
| 105 | // ---------------------------------------------------------- |
| 106 | // |
| 107 | // Do not refactor without careful consideration. |
| 108 | // Order of calculation is important. |
| 109 | // |
| 110 | int yearToUse; |
| 111 | // Initially, monthToUse is zero-based |
| 112 | int monthToUse = thisMonth - 1 + months; |
| 113 | if (monthToUse >= 0) { |
| 114 | yearToUse = thisYear + (monthToUse / iMax); |
| 115 | monthToUse = (monthToUse % iMax) + 1; |
| 116 | } else { |
| 117 | yearToUse = thisYear + (monthToUse / iMax) - 1; |
| 118 | monthToUse = Math.abs(monthToUse); |
| 119 | int remMonthToUse = monthToUse % iMax; |
| 120 | // Take care of the boundary condition |
| 121 | if (remMonthToUse == 0) { |
| 122 | remMonthToUse = iMax; |
| 123 | } |
| 124 | monthToUse = iMax - remMonthToUse + 1; |
| 125 | // Take care of the boundary condition |
| 126 | if (monthToUse == 1) { |
| 127 | yearToUse += 1; |
| 128 | } |
| 129 | } |
| 130 | // End of do not refactor. |
| 131 | // ---------------------------------------------------------- |
| 132 | |
| 133 | // |
| 134 | // Quietly force DOM to nearest sane value. |
| 135 | // |
| 136 | int dayToUse = iChronology.getDayOfMonth(instant, thisYear, thisMonth); |
| 137 | int maxDay = iChronology.getDaysInYearMonth(yearToUse, monthToUse); |
| 138 | if (dayToUse > maxDay) { |
| 139 | dayToUse = maxDay; |
| 140 | } |
| 141 | // |
| 142 | // get proper date part, and return result |
| 143 | // |
| 144 | long datePart = |
| 145 | iChronology.getYearMonthDayMillis(yearToUse, monthToUse, dayToUse); |
| 146 | return datePart + timePart; |
| 147 | } |
| 148 | |
| 149 | //----------------------------------------------------------------------- |
| 150 | public long add(long instant, long months) { |
| 151 | int i_months = (int)months; |
| 152 | if (i_months == months) { |
| 153 | return add(instant, i_months); |
| 154 | } |
| 155 | |
| 156 | // Copied from add(long, int) and modified slightly: |
| 157 | |
| 158 | long timePart = iChronology.getMillisOfDay(instant); |
| 159 | |
| 160 | int thisYear = iChronology.getYear(instant); |
| 161 | int thisMonth = iChronology.getMonthOfYear(instant, thisYear); |
| 162 | |
| 163 | long yearToUse; |
| 164 | long monthToUse = thisMonth - 1 + months; |
| 165 | if (monthToUse >= 0) { |
| 166 | yearToUse = thisYear + (monthToUse / iMax); |
| 167 | monthToUse = (monthToUse % iMax) + 1; |
| 168 | } else { |
| 169 | yearToUse = thisYear + (monthToUse / iMax) - 1; |
| 170 | monthToUse = Math.abs(monthToUse); |
| 171 | int remMonthToUse = (int)(monthToUse % iMax); |
| 172 | if (remMonthToUse == 0) { |
| 173 | remMonthToUse = iMax; |
| 174 | } |
| 175 | monthToUse = iMax - remMonthToUse + 1; |
| 176 | if (monthToUse == 1) { |
| 177 | yearToUse += 1; |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | if (yearToUse < iChronology.getMinYear() || |
| 182 | yearToUse > iChronology.getMaxYear()) { |
| 183 | |
| 184 | throw new IllegalArgumentException |
| 185 | ("Magnitude of add amount is too large: " + months); |
| 186 | } |
| 187 | |
| 188 | int i_yearToUse = (int)yearToUse; |
| 189 | int i_monthToUse = (int)monthToUse; |
| 190 | |
| 191 | int dayToUse = iChronology.getDayOfMonth(instant, thisYear, thisMonth); |
| 192 | int maxDay = iChronology.getDaysInYearMonth(i_yearToUse, i_monthToUse); |
| 193 | if (dayToUse > maxDay) { |
| 194 | dayToUse = maxDay; |
| 195 | } |
| 196 | |
| 197 | long datePart = |
| 198 | iChronology.getYearMonthDayMillis(i_yearToUse, i_monthToUse, dayToUse); |
| 199 | return datePart + timePart; |
| 200 | } |
| 201 | |
| 202 | //----------------------------------------------------------------------- |
| 203 | public int[] add(ReadablePartial partial, int fieldIndex, int[] values, int valueToAdd) { |
| 204 | // overridden as superclass algorithm can't handle |
| 205 | // 2004-02-29 + 48 months -> 2008-02-29 type dates |
| 206 | if (valueToAdd == 0) { |
| 207 | return values; |
| 208 | } |
| 209 | if (DateTimeUtils.isContiguous(partial)) { |
| 210 | long instant = 0L; |
| 211 | for (int i = 0, isize = partial.size(); i < isize; i++) { |
| 212 | instant = partial.getFieldType(i).getField(iChronology).set(instant, values[i]); |
| 213 | } |
| 214 | instant = add(instant, valueToAdd); |
| 215 | return iChronology.get(partial, instant); |
| 216 | } else { |
| 217 | return super.add(partial, fieldIndex, values, valueToAdd); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | //----------------------------------------------------------------------- |
| 222 | /** |
| 223 | * Add to the Month component of the specified time instant |
| 224 | * wrapping around within that component if necessary. |
| 225 | * |
| 226 | * @see org.joda.time.DateTimeField#addWrapField |
| 227 | * @param instant the time instant in millis to update. |
| 228 | * @param months the months to add (can be negative). |
| 229 | * @return the updated time instant. |
| 230 | */ |
| 231 | public long addWrapField(long instant, int months) { |
| 232 | return set(instant, FieldUtils.getWrappedValue(get(instant), months, MIN, iMax)); |
| 233 | } |
| 234 | |
| 235 | //----------------------------------------------------------------------- |
| 236 | public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) { |
| 237 | if (minuendInstant < subtrahendInstant) { |
| 238 | return -getDifference(subtrahendInstant, minuendInstant); |
| 239 | } |
| 240 | |
| 241 | int minuendYear = iChronology.getYear(minuendInstant); |
| 242 | int minuendMonth = iChronology.getMonthOfYear(minuendInstant, minuendYear); |
| 243 | int subtrahendYear = iChronology.getYear(subtrahendInstant); |
| 244 | int subtrahendMonth = iChronology.getMonthOfYear(subtrahendInstant, subtrahendYear); |
| 245 | |
| 246 | long difference = (minuendYear - subtrahendYear) * ((long) iMax) + minuendMonth - subtrahendMonth; |
| 247 | |
| 248 | // Before adjusting for remainder, account for special case of add |
| 249 | // where the day-of-month is forced to the nearest sane value. |
| 250 | int minuendDom = iChronology.getDayOfMonth |
| 251 | (minuendInstant, minuendYear, minuendMonth); |
| 252 | if (minuendDom == iChronology.getDaysInYearMonth(minuendYear, minuendMonth)) { |
| 253 | // Last day of the minuend month... |
| 254 | int subtrahendDom = iChronology.getDayOfMonth |
| 255 | (subtrahendInstant, subtrahendYear, subtrahendMonth); |
| 256 | if (subtrahendDom > minuendDom) { |
| 257 | // ...and day of subtrahend month is larger. |
| 258 | // Note: This works fine, but it ideally shouldn't invoke other |
| 259 | // fields from within a field. |
| 260 | subtrahendInstant = iChronology.dayOfMonth().set(subtrahendInstant, minuendDom); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | // Inlined remainder method to avoid duplicate calls. |
| 265 | long minuendRem = minuendInstant |
| 266 | - iChronology.getYearMonthMillis(minuendYear, minuendMonth); |
| 267 | long subtrahendRem = subtrahendInstant |
| 268 | - iChronology.getYearMonthMillis(subtrahendYear, subtrahendMonth); |
| 269 | |
| 270 | if (minuendRem < subtrahendRem) { |
| 271 | difference--; |
| 272 | } |
| 273 | |
| 274 | return difference; |
| 275 | } |
| 276 | |
| 277 | //----------------------------------------------------------------------- |
| 278 | /** |
| 279 | * Set the Month component of the specified time instant.<p> |
| 280 | * If the new month has less total days than the specified |
| 281 | * day of the month, this value is coerced to the nearest |
| 282 | * sane value. e.g.<p> |
| 283 | * 07-31 to month 6 = 06-30<p> |
| 284 | * 03-31 to month 2 = 02-28 or 02-29 depending<p> |
| 285 | * |
| 286 | * @param instant the time instant in millis to update. |
| 287 | * @param month the month (1,12) to update the time to. |
| 288 | * @return the updated time instant. |
| 289 | * @throws IllegalArgumentException if month is invalid |
| 290 | */ |
| 291 | public long set(long instant, int month) { |
| 292 | FieldUtils.verifyValueBounds(this, month, MIN, iMax); |
| 293 | // |
| 294 | int thisYear = iChronology.getYear(instant); |
| 295 | // |
| 296 | int thisDom = iChronology.getDayOfMonth(instant, thisYear); |
| 297 | int maxDom = iChronology.getDaysInYearMonth(thisYear, month); |
| 298 | if (thisDom > maxDom) { |
| 299 | // Quietly force DOM to nearest sane value. |
| 300 | thisDom = maxDom; |
| 301 | } |
| 302 | // Return newly calculated millis value |
| 303 | return iChronology.getYearMonthDayMillis(thisYear, month, thisDom) + |
| 304 | iChronology.getMillisOfDay(instant); |
| 305 | } |
| 306 | |
| 307 | //----------------------------------------------------------------------- |
| 308 | public DurationField getRangeDurationField() { |
| 309 | return iChronology.years(); |
| 310 | } |
| 311 | |
| 312 | //----------------------------------------------------------------------- |
| 313 | public boolean isLeap(long instant) { |
| 314 | int thisYear = iChronology.getYear(instant); |
| 315 | if (iChronology.isLeapYear(thisYear)) { |
| 316 | return (iChronology.getMonthOfYear(instant, thisYear) == iLeapMonth); |
| 317 | } |
| 318 | return false; |
| 319 | } |
| 320 | |
| 321 | //----------------------------------------------------------------------- |
| 322 | public int getLeapAmount(long instant) { |
| 323 | return isLeap(instant) ? 1 : 0; |
| 324 | } |
| 325 | |
| 326 | //----------------------------------------------------------------------- |
| 327 | public DurationField getLeapDurationField() { |
| 328 | return iChronology.days(); |
| 329 | } |
| 330 | |
| 331 | //----------------------------------------------------------------------- |
| 332 | public int getMinimumValue() { |
| 333 | return MIN; |
| 334 | } |
| 335 | |
| 336 | //----------------------------------------------------------------------- |
| 337 | public int getMaximumValue() { |
| 338 | return iMax; |
| 339 | } |
| 340 | |
| 341 | //----------------------------------------------------------------------- |
| 342 | public long roundFloor(long instant) { |
| 343 | int year = iChronology.getYear(instant); |
| 344 | int month = iChronology.getMonthOfYear(instant, year); |
| 345 | return iChronology.getYearMonthMillis(year, month); |
| 346 | } |
| 347 | |
| 348 | //----------------------------------------------------------------------- |
| 349 | public long remainder(long instant) { |
| 350 | return instant - roundFloor(instant); |
| 351 | } |
| 352 | |
| 353 | //----------------------------------------------------------------------- |
| 354 | /** |
| 355 | * Serialization singleton |
| 356 | */ |
| 357 | private Object readResolve() { |
| 358 | return iChronology.monthOfYear(); |
| 359 | } |
| 360 | } |