Source for org.jfree.date.SpreadsheetDate

   1: /* ========================================================================
   2:  * JCommon : a free general purpose class library for the Java(tm) platform
   3:  * ========================================================================
   4:  *
   5:  * (C) Copyright 2000-2006, by Object Refinery Limited and Contributors.
   6:  * 
   7:  * Project Info:  http://www.jfree.org/jcommon/index.html
   8:  *
   9:  * This library is free software; you can redistribute it and/or modify it 
  10:  * under the terms of the GNU Lesser General Public License as published by 
  11:  * the Free Software Foundation; either version 2.1 of the License, or 
  12:  * (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but 
  15:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
  16:  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
  17:  * License for more details.
  18:  *
  19:  * You should have received a copy of the GNU Lesser General Public
  20:  * License along with this library; if not, write to the Free Software
  21:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
  22:  * USA.  
  23:  *
  24:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
  25:  * in the United States and other countries.]
  26:  *
  27:  * --------------------
  28:  * SpreadsheetDate.java
  29:  * --------------------
  30:  * (C) Copyright 2000-2006, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   -;
  34:  *
  35:  * $Id: SpreadsheetDate.java,v 1.10 2006/08/29 13:59:30 mungady Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 11-Oct-2001 : Version 1 (DG);
  40:  * 05-Nov-2001 : Added getDescription() and setDescription() methods (DG);
  41:  * 12-Nov-2001 : Changed name from ExcelDate.java to SpreadsheetDate.java (DG);
  42:  *               Fixed a bug in calculating day, month and year from serial 
  43:  *               number (DG);
  44:  * 24-Jan-2002 : Fixed a bug in calculating the serial number from the day, 
  45:  *               month and year.  Thanks to Trevor Hills for the report (DG);
  46:  * 29-May-2002 : Added equals(Object) method (SourceForge ID 558850) (DG);
  47:  * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG);
  48:  * 13-Mar-2003 : Implemented Serializable (DG);
  49:  * 04-Sep-2003 : Completed isInRange() methods (DG);
  50:  * 05-Sep-2003 : Implemented Comparable (DG);
  51:  * 21-Oct-2003 : Added hashCode() method (DG);
  52:  * 29-Aug-2006 : Removed redundant description attribute (DG);
  53:  *
  54:  */
  55: 
  56: package org.jfree.date;
  57: 
  58: import java.util.Calendar;
  59: import java.util.Date;
  60: 
  61: /**
  62:  * Represents a date using an integer, in a similar fashion to the
  63:  * implementation in Microsoft Excel.  The range of dates supported is
  64:  * 1-Jan-1900 to 31-Dec-9999.
  65:  * <P>
  66:  * Be aware that there is a deliberate bug in Excel that recognises the year
  67:  * 1900 as a leap year when in fact it is not a leap year. You can find more
  68:  * information on the Microsoft website in article Q181370:
  69:  * <P>
  70:  * http://support.microsoft.com/support/kb/articles/Q181/3/70.asp
  71:  * <P>
  72:  * Excel uses the convention that 1-Jan-1900 = 1.  This class uses the
  73:  * convention 1-Jan-1900 = 2.
  74:  * The result is that the day number in this class will be different to the
  75:  * Excel figure for January and February 1900...but then Excel adds in an extra
  76:  * day (29-Feb-1900 which does not actually exist!) and from that point forward
  77:  * the day numbers will match.
  78:  *
  79:  * @author David Gilbert
  80:  */
  81: public class SpreadsheetDate extends SerialDate {
  82: 
  83:     /** For serialization. */
  84:     private static final long serialVersionUID = -2039586705374454461L;
  85:     
  86:     /** 
  87:      * The day number (1-Jan-1900 = 2, 2-Jan-1900 = 3, ..., 31-Dec-9999 = 
  88:      * 2958465). 
  89:      */
  90:     private final int serial;
  91: 
  92:     /** The day of the month (1 to 28, 29, 30 or 31 depending on the month). */
  93:     private final int day;
  94: 
  95:     /** The month of the year (1 to 12). */
  96:     private final int month;
  97: 
  98:     /** The year (1900 to 9999). */
  99:     private final int year;
 100: 
 101:     /**
 102:      * Creates a new date instance.
 103:      *
 104:      * @param day  the day (in the range 1 to 28/29/30/31).
 105:      * @param month  the month (in the range 1 to 12).
 106:      * @param year  the year (in the range 1900 to 9999).
 107:      */
 108:     public SpreadsheetDate(final int day, final int month, final int year) {
 109: 
 110:         if ((year >= 1900) && (year <= 9999)) {
 111:             this.year = year;
 112:         }
 113:         else {
 114:             throw new IllegalArgumentException(
 115:                 "The 'year' argument must be in range 1900 to 9999."
 116:             );
 117:         }
 118: 
 119:         if ((month >= MonthConstants.JANUARY) 
 120:                 && (month <= MonthConstants.DECEMBER)) {
 121:             this.month = month;
 122:         }
 123:         else {
 124:             throw new IllegalArgumentException(
 125:                 "The 'month' argument must be in the range 1 to 12."
 126:             );
 127:         }
 128: 
 129:         if ((day >= 1) && (day <= SerialDate.lastDayOfMonth(month, year))) {
 130:             this.day = day;
 131:         }
 132:         else {
 133:             throw new IllegalArgumentException("Invalid 'day' argument.");
 134:         }
 135: 
 136:         // the serial number needs to be synchronised with the day-month-year...
 137:         this.serial = calcSerial(day, month, year);
 138: 
 139:     }
 140: 
 141:     /**
 142:      * Standard constructor - creates a new date object representing the
 143:      * specified day number (which should be in the range 2 to 2958465.
 144:      *
 145:      * @param serial  the serial number for the day (range: 2 to 2958465).
 146:      */
 147:     public SpreadsheetDate(final int serial) {
 148: 
 149:         if ((serial >= SERIAL_LOWER_BOUND) && (serial <= SERIAL_UPPER_BOUND)) {
 150:             this.serial = serial;
 151:         }
 152:         else {
 153:             throw new IllegalArgumentException(
 154:                 "SpreadsheetDate: Serial must be in range 2 to 2958465.");
 155:         }
 156: 
 157:         // the day-month-year needs to be synchronised with the serial number...
 158:       // get the year from the serial date
 159:       final int days = this.serial - SERIAL_LOWER_BOUND;
 160:       // overestimated because we ignored leap days
 161:       final int overestimatedYYYY = 1900 + (days / 365);
 162:       final int leaps = SerialDate.leapYearCount(overestimatedYYYY);
 163:       final int nonleapdays = days - leaps;
 164:       // underestimated because we overestimated years
 165:       int underestimatedYYYY = 1900 + (nonleapdays / 365);
 166: 
 167:       if (underestimatedYYYY == overestimatedYYYY) {
 168:           this.year = underestimatedYYYY;
 169:       }
 170:       else {
 171:           int ss1 = calcSerial(1, 1, underestimatedYYYY);
 172:           while (ss1 <= this.serial) {
 173:               underestimatedYYYY = underestimatedYYYY + 1;
 174:               ss1 = calcSerial(1, 1, underestimatedYYYY);
 175:           }
 176:           this.year = underestimatedYYYY - 1;
 177:       }
 178: 
 179:       final int ss2 = calcSerial(1, 1, this.year);
 180: 
 181:       int[] daysToEndOfPrecedingMonth 
 182:           = AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH;
 183: 
 184:       if (isLeapYear(this.year)) {
 185:           daysToEndOfPrecedingMonth 
 186:               = LEAP_YEAR_AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH;
 187:       }
 188: 
 189:       // get the month from the serial date
 190:       int mm = 1;
 191:       int sss = ss2 + daysToEndOfPrecedingMonth[mm] - 1;
 192:       while (sss < this.serial) {
 193:           mm = mm + 1;
 194:           sss = ss2 + daysToEndOfPrecedingMonth[mm] - 1;
 195:       }
 196:       this.month = mm - 1;
 197: 
 198:       // what's left is d(+1);
 199:       this.day = this.serial - ss2 
 200:                  - daysToEndOfPrecedingMonth[this.month] + 1;
 201: 
 202:     }
 203: 
 204:     /**
 205:      * Returns the serial number for the date, where 1 January 1900 = 2
 206:      * (this corresponds, almost, to the numbering system used in Microsoft
 207:      * Excel for Windows and Lotus 1-2-3).
 208:      *
 209:      * @return The serial number of this date.
 210:      */
 211:     public int toSerial() {
 212:         return this.serial;
 213:     }
 214: 
 215:     /**
 216:      * Returns a <code>java.util.Date</code> equivalent to this date.
 217:      *
 218:      * @return The date.
 219:      */
 220:     public Date toDate() {
 221:         final Calendar calendar = Calendar.getInstance();
 222:         calendar.set(getYYYY(), getMonth() - 1, getDayOfMonth(), 0, 0, 0);
 223:         return calendar.getTime();
 224:     }
 225: 
 226:     /**
 227:      * Returns the year (assume a valid range of 1900 to 9999).
 228:      *
 229:      * @return The year.
 230:      */
 231:     public int getYYYY() {
 232:         return this.year;
 233:     }
 234: 
 235:     /**
 236:      * Returns the month (January = 1, February = 2, March = 3).
 237:      *
 238:      * @return The month of the year.
 239:      */
 240:     public int getMonth() {
 241:         return this.month;
 242:     }
 243: 
 244:     /**
 245:      * Returns the day of the month.
 246:      *
 247:      * @return The day of the month.
 248:      */
 249:     public int getDayOfMonth() {
 250:         return this.day;
 251:     }
 252: 
 253:     /**
 254:      * Returns a code representing the day of the week.
 255:      * <P>
 256:      * The codes are defined in the {@link SerialDate} class as: 
 257:      * <code>SUNDAY</code>, <code>MONDAY</code>, <code>TUESDAY</code>, 
 258:      * <code>WEDNESDAY</code>, <code>THURSDAY</code>, <code>FRIDAY</code>, and 
 259:      * <code>SATURDAY</code>.
 260:      *
 261:      * @return A code representing the day of the week.
 262:      */
 263:     public int getDayOfWeek() {
 264:         return (this.serial + 6) % 7 + 1;
 265:     }
 266: 
 267:     /**
 268:      * Tests the equality of this date with an arbitrary object.
 269:      * <P>
 270:      * This method will return true ONLY if the object is an instance of the
 271:      * {@link SerialDate} base class, and it represents the same day as this
 272:      * {@link SpreadsheetDate}.
 273:      *
 274:      * @param object  the object to compare (<code>null</code> permitted).
 275:      *
 276:      * @return A boolean.
 277:      */
 278:     public boolean equals(final Object object) {
 279: 
 280:         if (object instanceof SerialDate) {
 281:             final SerialDate s = (SerialDate) object;
 282:             return (s.toSerial() == this.toSerial());
 283:         }
 284:         else {
 285:             return false;
 286:         }
 287: 
 288:     }
 289: 
 290:     /**
 291:      * Returns a hash code for this object instance.
 292:      * 
 293:      * @return A hash code.
 294:      */
 295:     public int hashCode() {
 296:         return toSerial();
 297:     }
 298: 
 299:     /**
 300:      * Returns the difference (in days) between this date and the specified 
 301:      * 'other' date.
 302:      *
 303:      * @param other  the date being compared to.
 304:      *
 305:      * @return The difference (in days) between this date and the specified 
 306:      *         'other' date.
 307:      */
 308:     public int compare(final SerialDate other) {
 309:         return this.serial - other.toSerial();
 310:     }
 311: 
 312:     /**
 313:      * Implements the method required by the Comparable interface.
 314:      * 
 315:      * @param other  the other object (usually another SerialDate).
 316:      * 
 317:      * @return A negative integer, zero, or a positive integer as this object 
 318:      *         is less than, equal to, or greater than the specified object.
 319:      */
 320:     public int compareTo(final Object other) {
 321:         return compare((SerialDate) other);    
 322:     }
 323:     
 324:     /**
 325:      * Returns true if this SerialDate represents the same date as the
 326:      * specified SerialDate.
 327:      *
 328:      * @param other  the date being compared to.
 329:      *
 330:      * @return <code>true</code> if this SerialDate represents the same date as
 331:      *         the specified SerialDate.
 332:      */
 333:     public boolean isOn(final SerialDate other) {
 334:         return (this.serial == other.toSerial());
 335:     }
 336: 
 337:     /**
 338:      * Returns true if this SerialDate represents an earlier date compared to
 339:      * the specified SerialDate.
 340:      *
 341:      * @param other  the date being compared to.
 342:      *
 343:      * @return <code>true</code> if this SerialDate represents an earlier date
 344:      *         compared to the specified SerialDate.
 345:      */
 346:     public boolean isBefore(final SerialDate other) {
 347:         return (this.serial < other.toSerial());
 348:     }
 349: 
 350:     /**
 351:      * Returns true if this SerialDate represents the same date as the
 352:      * specified SerialDate.
 353:      *
 354:      * @param other  the date being compared to.
 355:      *
 356:      * @return <code>true</code> if this SerialDate represents the same date
 357:      *         as the specified SerialDate.
 358:      */
 359:     public boolean isOnOrBefore(final SerialDate other) {
 360:         return (this.serial <= other.toSerial());
 361:     }
 362: 
 363:     /**
 364:      * Returns true if this SerialDate represents the same date as the
 365:      * specified SerialDate.
 366:      *
 367:      * @param other  the date being compared to.
 368:      *
 369:      * @return <code>true</code> if this SerialDate represents the same date
 370:      *         as the specified SerialDate.
 371:      */
 372:     public boolean isAfter(final SerialDate other) {
 373:         return (this.serial > other.toSerial());
 374:     }
 375: 
 376:     /**
 377:      * Returns true if this SerialDate represents the same date as the
 378:      * specified SerialDate.
 379:      *
 380:      * @param other  the date being compared to.
 381:      *
 382:      * @return <code>true</code> if this SerialDate represents the same date as
 383:      *         the specified SerialDate.
 384:      */
 385:     public boolean isOnOrAfter(final SerialDate other) {
 386:         return (this.serial >= other.toSerial());
 387:     }
 388: 
 389:     /**
 390:      * Returns <code>true</code> if this {@link SerialDate} is within the 
 391:      * specified range (INCLUSIVE).  The date order of d1 and d2 is not 
 392:      * important.
 393:      *
 394:      * @param d1  a boundary date for the range.
 395:      * @param d2  the other boundary date for the range.
 396:      *
 397:      * @return A boolean.
 398:      */
 399:     public boolean isInRange(final SerialDate d1, final SerialDate d2) {
 400:         return isInRange(d1, d2, SerialDate.INCLUDE_BOTH);
 401:     }
 402: 
 403:     /**
 404:      * Returns true if this SerialDate is within the specified range (caller
 405:      * specifies whether or not the end-points are included).  The order of d1
 406:      * and d2 is not important.
 407:      *
 408:      * @param d1  one boundary date for the range.
 409:      * @param d2  a second boundary date for the range.
 410:      * @param include  a code that controls whether or not the start and end 
 411:      *                 dates are included in the range.
 412:      *
 413:      * @return <code>true</code> if this SerialDate is within the specified 
 414:      *         range.
 415:      */
 416:     public boolean isInRange(final SerialDate d1, final SerialDate d2, 
 417:                              final int include) {
 418:         final int s1 = d1.toSerial();
 419:         final int s2 = d2.toSerial();
 420:         final int start = Math.min(s1, s2);
 421:         final int end = Math.max(s1, s2);
 422:         
 423:         final int s = toSerial();
 424:         if (include == SerialDate.INCLUDE_BOTH) {
 425:             return (s >= start && s <= end);
 426:         }
 427:         else if (include == SerialDate.INCLUDE_FIRST) {
 428:             return (s >= start && s < end);            
 429:         }
 430:         else if (include == SerialDate.INCLUDE_SECOND) {
 431:             return (s > start && s <= end);            
 432:         }
 433:         else {
 434:             return (s > start && s < end);            
 435:         }    
 436:     }
 437: 
 438:     /**
 439:      * Calculate the serial number from the day, month and year.
 440:      * <P>
 441:      * 1-Jan-1900 = 2.
 442:      *
 443:      * @param d  the day.
 444:      * @param m  the month.
 445:      * @param y  the year.
 446:      *
 447:      * @return the serial number from the day, month and year.
 448:      */
 449:     private int calcSerial(final int d, final int m, final int y) {
 450:         final int yy = ((y - 1900) * 365) + SerialDate.leapYearCount(y - 1);
 451:         int mm = SerialDate.AGGREGATE_DAYS_TO_END_OF_PRECEDING_MONTH[m];
 452:         if (m > MonthConstants.FEBRUARY) {
 453:             if (SerialDate.isLeapYear(y)) {
 454:                 mm = mm + 1;
 455:             }
 456:         }
 457:         final int dd = d;
 458:         return yy + mm + dd + 1;
 459:     }
 460: 
 461: }