Source for org.jfree.data.time.Week

   1: /* ===========================================================
   2:  * JFreeChart : a free chart 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/jfreechart/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:  * Week.java
  29:  * ---------
  30:  * (C) Copyright 2001-2004, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   Aimin Han;
  34:  *
  35:  * $Id: Week.java,v 1.7.2.2 2006/04/06 13:23:57 mungady Exp $
  36:  *
  37:  * Changes
  38:  * -------
  39:  * 11-Oct-2001 : Version 1 (DG);
  40:  * 18-Dec-2001 : Changed order of parameters in constructor (DG);
  41:  * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
  42:  * 29-Jan-2002 : Worked on the parseWeek() method (DG);
  43:  * 13-Feb-2002 : Fixed bug in Week(Date) constructor (DG);
  44:  * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to 
  45:  *               evaluate with reference to a particular time zone (DG);
  46:  * 05-Apr-2002 : Reinstated this class to the JCommon library (DG);
  47:  * 24-Jun-2002 : Removed unnecessary main method (DG);
  48:  * 10-Sep-2002 : Added getSerialIndex() method (DG);
  49:  * 06-Oct-2002 : Fixed errors reported by Checkstyle (DG);
  50:  * 18-Oct-2002 : Changed to observe 52 or 53 weeks per year, consistent with 
  51:  *               GregorianCalendar. Thanks to Aimin Han for the code (DG);
  52:  * 02-Jan-2003 : Removed debug code (DG);
  53:  * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented 
  54:  *               Serializable (DG);
  55:  * 21-Oct-2003 : Added hashCode() method (DG);
  56:  * 24-May-2004 : Modified getFirstMillisecond() and getLastMillisecond() to 
  57:  *               take account of firstDayOfWeek setting in Java's Calendar 
  58:  *               class (DG);
  59:  * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
  60:  * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for 
  61:  *               JDK 1.3 (DG);
  62:  * ------------- JFREECHART 1.0.0 ---------------------------------------------
  63:  * 06-Mar-2006 : Fix for bug 1448828, incorrect calculation of week and year
  64:  *               for the first few days of some years (DG);
  65:  *
  66:  */
  67: 
  68: package org.jfree.data.time;
  69: 
  70: import java.io.Serializable;
  71: import java.util.Calendar;
  72: import java.util.Date;
  73: import java.util.TimeZone;
  74: 
  75: /**
  76:  * A calendar week.  All years are considered to have 53 weeks, numbered from 1 
  77:  * to 53, although in many cases the 53rd week is empty.  Most of the time, the
  78:  * 1st week of the year *begins* in the previous calendar year, but it always 
  79:  * finishes in the current year (this behaviour matches the workings of the 
  80:  * <code>GregorianCalendar</code> class).
  81:  * <P>
  82:  * This class is immutable, which is a requirement for all 
  83:  * {@link RegularTimePeriod} subclasses.
  84:  */
  85: public class Week extends RegularTimePeriod implements Serializable {
  86: 
  87:     /** For serialization. */
  88:     private static final long serialVersionUID = 1856387786939865061L;
  89:     
  90:     /** Constant for the first week in the year. */
  91:     public static final int FIRST_WEEK_IN_YEAR = 1;
  92: 
  93:     /** Constant for the last week in the year. */
  94:     public static final int LAST_WEEK_IN_YEAR = 53;
  95: 
  96:     /** The year in which the week falls. */
  97:     private Year year;
  98: 
  99:     /** The week (1-53). */
 100:     private int week;
 101: 
 102:     /**
 103:      * Creates a new time period for the week in which the current system 
 104:      * date/time falls.
 105:      */
 106:     public Week() {
 107:         this(new Date());
 108:     }
 109: 
 110:     /**
 111:      * Creates a time period representing the week in the specified year.
 112:      *
 113:      * @param week  the week (1 to 53).
 114:      * @param year  the year (1900 to 9999).
 115:      */
 116:     public Week(int week, int year) {
 117:         this(week, new Year(year));
 118:     }
 119: 
 120:     /**
 121:      * Creates a time period representing the week in the specified year.
 122:      *
 123:      * @param week  the week (1 to 53).
 124:      * @param year  the year (1900 to 9999).
 125:      */
 126:     public Week(int week, Year year) {
 127:         if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
 128:             throw new IllegalArgumentException(
 129:                 "The 'week' argument must be in the range 1 - 53."
 130:             );
 131:         }
 132:         this.week = week;
 133:         this.year = year;
 134:     }
 135: 
 136:     /**
 137:      * Creates a time period for the week in which the specified date/time 
 138:      * falls.
 139:      *
 140:      * @param time  the time (<code>null</code> not permitted).
 141:      */
 142:     public Week(Date time) {
 143:         // defer argument checking...
 144:         this(time, RegularTimePeriod.DEFAULT_TIME_ZONE);
 145:     }
 146: 
 147:     /**
 148:      * Creates a time period for the week in which the specified date/time 
 149:      * falls, calculated relative to the specified time zone.
 150:      *
 151:      * @param time  the date/time (<code>null</code> not permitted).
 152:      * @param zone  the time zone (<code>null</code> not permitted).
 153:      */
 154:     public Week(Date time, TimeZone zone) {
 155:         if (time == null) {
 156:             throw new IllegalArgumentException("Null 'time' argument.");   
 157:         }
 158:         if (zone == null) {
 159:             throw new IllegalArgumentException("Null 'zone' argument.");   
 160:         }
 161:         Calendar calendar = Calendar.getInstance(zone);
 162:         calendar.setTime(time);
 163: 
 164:         // sometimes the last few days of the year are considered to fall in 
 165:         // the *first* week of the following year.  Refer to the Javadocs for 
 166:         // GregorianCalendar.
 167:         int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
 168:         if (tempWeek == 1 
 169:                 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
 170:             this.week = 1;
 171:             this.year =  new Year(calendar.get(Calendar.YEAR) + 1);
 172:         }
 173:         else {
 174:             this.week = Math.min(tempWeek, LAST_WEEK_IN_YEAR);
 175:             int yyyy = calendar.get(Calendar.YEAR);
 176:             // alternatively, sometimes the first few days of the year are
 177:             // considered to fall in the *last* week of the previous year...
 178:             if (calendar.get(Calendar.MONTH) == Calendar.JANUARY 
 179:                     && this.week >= 52) {
 180:                 yyyy--; 
 181:             }
 182:             this.year = new Year(yyyy);
 183:         }
 184: 
 185:     }
 186: 
 187:     /**
 188:      * Returns the year in which the week falls.
 189:      *
 190:      * @return The year (never <code>null</code>).
 191:      */
 192:     public Year getYear() {
 193:         return this.year;
 194:     }
 195: 
 196:     /**
 197:      * Returns the year in which the week falls, as an integer value.
 198:      *
 199:      * @return The year.
 200:      */
 201:     public int getYearValue() {
 202:         return this.year.getYear();
 203:     }
 204: 
 205:     /**
 206:      * Returns the week.
 207:      *
 208:      * @return The week.
 209:      */
 210:     public int getWeek() {
 211:         return this.week;
 212:     }
 213: 
 214:     /**
 215:      * Returns the week preceding this one.  This method will return 
 216:      * <code>null</code> for some lower limit on the range of weeks (currently 
 217:      * week 1, 1900).  For week 1 of any year, the previous week is always week 
 218:      * 53, but week 53 may not contain any days (you should check for this).
 219:      *
 220:      * @return The preceding week (possibly <code>null</code>).
 221:      */
 222:     public RegularTimePeriod previous() {
 223: 
 224:         Week result;
 225:         if (this.week != FIRST_WEEK_IN_YEAR) {
 226:             result = new Week(this.week - 1, this.year);
 227:         }
 228:         else {
 229:             // we need to work out if the previous year has 52 or 53 weeks...
 230:             Year prevYear = (Year) this.year.previous();
 231:             if (prevYear != null) {
 232:                 int yy = prevYear.getYear();
 233:                 Calendar prevYearCalendar = Calendar.getInstance();
 234:                 prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
 235:                 result = new Week(
 236:                     prevYearCalendar.getActualMaximum(Calendar.WEEK_OF_YEAR), 
 237:                     prevYear
 238:                 );
 239:             }
 240:             else {
 241:                 result = null;
 242:             }
 243:         }
 244:         return result;
 245: 
 246:     }
 247: 
 248:     /**
 249:      * Returns the week following this one.  This method will return 
 250:      * <code>null</code> for some upper limit on the range of weeks (currently 
 251:      * week 53, 9999).  For week 52 of any year, the following week is always 
 252:      * week 53, but week 53 may not contain any days (you should check for 
 253:      * this).
 254:      *
 255:      * @return The following week (possibly <code>null</code>).
 256:      */
 257:     public RegularTimePeriod next() {
 258: 
 259:         Week result;
 260:         if (this.week < 52) {
 261:             result = new Week(this.week + 1, this.year);
 262:         }
 263:         else {
 264:             Calendar calendar = Calendar.getInstance();
 265:             calendar.set(this.year.getYear(), Calendar.DECEMBER, 31);
 266:             int actualMaxWeek 
 267:                 = calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
 268:             if (this.week != actualMaxWeek) {
 269:                 result = new Week(this.week + 1, this.year);
 270:             }
 271:             else {
 272:                 Year nextYear = (Year) this.year.next();
 273:                 if (nextYear != null) {
 274:                     result = new Week(FIRST_WEEK_IN_YEAR, nextYear);
 275:                 }
 276:                 else {
 277:                     result = null;
 278:                 }
 279:             }
 280:         }
 281:         return result;
 282: 
 283:     }
 284: 
 285:     /**
 286:      * Returns a serial index number for the week.
 287:      *
 288:      * @return The serial index number.
 289:      */
 290:     public long getSerialIndex() {
 291:         return this.year.getYear() * 53L + this.week;
 292:     }
 293: 
 294:     /**
 295:      * Returns the first millisecond of the week, evaluated using the supplied
 296:      * calendar (which determines the time zone).
 297:      *
 298:      * @param calendar  the calendar.
 299:      *
 300:      * @return The first millisecond of the week.
 301:      */
 302:     public long getFirstMillisecond(Calendar calendar) {
 303:         Calendar c = (Calendar) calendar.clone();
 304:         c.clear();
 305:         c.set(Calendar.YEAR, this.year.getYear());
 306:         c.set(Calendar.WEEK_OF_YEAR, this.week);
 307:         c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
 308:         c.set(Calendar.HOUR, 0);
 309:         c.set(Calendar.MINUTE, 0);
 310:         c.set(Calendar.SECOND, 0);
 311:         c.set(Calendar.MILLISECOND, 0);
 312:         //return c.getTimeInMillis();  // this won't work for JDK 1.3
 313:         return c.getTime().getTime();
 314:     }
 315: 
 316:     /**
 317:      * Returns the last millisecond of the week, evaluated using the supplied
 318:      * calendar (which determines the time zone).
 319:      *
 320:      * @param calendar  the calendar.
 321:      *
 322:      * @return The last millisecond of the week.
 323:      */
 324:     public long getLastMillisecond(Calendar calendar) {
 325:         RegularTimePeriod next = next();
 326:         return next.getFirstMillisecond(calendar) - 1;
 327:     }
 328: 
 329:     /**
 330:      * Returns a string representing the week (e.g. "Week 9, 2002").
 331:      *
 332:      * TODO: look at internationalisation.
 333:      *
 334:      * @return A string representing the week.
 335:      */
 336:     public String toString() {
 337:         return "Week " + this.week + ", " + this.year;
 338:     }
 339: 
 340:     /**
 341:      * Tests the equality of this Week object to an arbitrary object.  Returns
 342:      * true if the target is a Week instance representing the same week as this
 343:      * object.  In all other cases, returns false.
 344:      * @param obj The object.
 345:      *
 346:      * @return <code>true</code> if week and year of this and object are the 
 347:      *         same.
 348:      */
 349:     public boolean equals(Object obj) {
 350: 
 351:         if (obj == this) {
 352:             return true;
 353:         }
 354:         if (!(obj instanceof Week)) {
 355:             return false;
 356:         }
 357:         Week that = (Week) obj;
 358:         if (this.week != that.week) {
 359:             return false;
 360:         }
 361:         if (!this.year.equals(that.year)) {
 362:             return false;
 363:         }
 364:         return true;
 365: 
 366:     }
 367: 
 368:     /**
 369:      * Returns a hash code for this object instance.  The approach described by
 370:      * Joshua Bloch in "Effective Java" has been used here:
 371:      * <p>
 372:      * <code>http://developer.java.sun.com/developer/Books/effectivejava
 373:      * /Chapter3.pdf</code>
 374:      * 
 375:      * @return A hash code.
 376:      */
 377:     public int hashCode() {
 378:         int result = 17;
 379:         result = 37 * result + this.week;
 380:         result = 37 * result + this.year.hashCode();
 381:         return result;
 382:     }
 383: 
 384:     /**
 385:      * Returns an integer indicating the order of this Week object relative to
 386:      * the specified object:
 387:      *
 388:      * negative == before, zero == same, positive == after.
 389:      *
 390:      * @param o1  the object to compare.
 391:      *
 392:      * @return negative == before, zero == same, positive == after.
 393:      */
 394:     public int compareTo(Object o1) {
 395: 
 396:         int result;
 397: 
 398:         // CASE 1 : Comparing to another Week object
 399:         // --------------------------------------------
 400:         if (o1 instanceof Week) {
 401:             Week w = (Week) o1;
 402:             result = this.year.getYear() - w.getYear().getYear();
 403:             if (result == 0) {
 404:                 result = this.week - w.getWeek();
 405:             }
 406:         }
 407: 
 408:         // CASE 2 : Comparing to another TimePeriod object
 409:         // -----------------------------------------------
 410:         else if (o1 instanceof RegularTimePeriod) {
 411:             // more difficult case - evaluate later...
 412:             result = 0;
 413:         }
 414: 
 415:         // CASE 3 : Comparing to a non-TimePeriod object
 416:         // ---------------------------------------------
 417:         else {
 418:             // consider time periods to be ordered after general objects
 419:             result = 1;
 420:         }
 421: 
 422:         return result;
 423: 
 424:     }
 425: 
 426:     /**
 427:      * Parses the string argument as a week.
 428:      * <P>
 429:      * This method is required to accept the format "YYYY-Wnn".  It will also
 430:      * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
 431:      *
 432:      * @param s  string to parse.
 433:      *
 434:      * @return <code>null</code> if the string is not parseable, the week 
 435:      *         otherwise.
 436:      */
 437:     public static Week parseWeek(String s) {
 438: 
 439:         Week result = null;
 440:         if (s != null) {
 441: 
 442:             // trim whitespace from either end of the string
 443:             s = s.trim();
 444: 
 445:             int i = Week.findSeparator(s);
 446:             if (i != -1) {
 447:                 String s1 = s.substring(0, i).trim();
 448:                 String s2 = s.substring(i + 1, s.length()).trim();
 449: 
 450:                 Year y = Week.evaluateAsYear(s1);
 451:                 int w;
 452:                 if (y != null) {
 453:                     w = Week.stringToWeek(s2);
 454:                     if (w == -1) {
 455:                         throw new TimePeriodFormatException(
 456:                             "Can't evaluate the week."
 457:                         );
 458:                     }
 459:                     result = new Week(w, y);
 460:                 }
 461:                 else {
 462:                     y = Week.evaluateAsYear(s2);
 463:                     if (y != null) {
 464:                         w = Week.stringToWeek(s1);
 465:                         if (w == -1) {
 466:                             throw new TimePeriodFormatException(
 467:                                 "Can't evaluate the week."
 468:                             );
 469:                         }
 470:                         result = new Week(w, y);
 471:                     }
 472:                     else {
 473:                         throw new TimePeriodFormatException(
 474:                             "Can't evaluate the year."
 475:                         );
 476:                     }
 477:                 }
 478: 
 479:             }
 480:             else {
 481:                 throw new TimePeriodFormatException(
 482:                     "Could not find separator."
 483:                 );
 484:             }
 485: 
 486:         }
 487:         return result;
 488: 
 489:     }
 490: 
 491:     /**
 492:      * Finds the first occurrence of ' ', '-', ',' or '.'
 493:      *
 494:      * @param s  the string to parse.
 495:      *
 496:      * @return <code>-1</code> if none of the characters was found, the
 497:      *      index of the first occurrence otherwise.
 498:      */
 499:     private static int findSeparator(String s) {
 500: 
 501:         int result = s.indexOf('-');
 502:         if (result == -1) {
 503:             result = s.indexOf(',');
 504:         }
 505:         if (result == -1) {
 506:             result = s.indexOf(' ');
 507:         }
 508:         if (result == -1) {
 509:             result = s.indexOf('.');
 510:         }
 511:         return result;
 512:     }
 513: 
 514:     /**
 515:      * Creates a year from a string, or returns null (format exceptions
 516:      * suppressed).
 517:      *
 518:      * @param s  string to parse.
 519:      *
 520:      * @return <code>null</code> if the string is not parseable, the year 
 521:      *         otherwise.
 522:      */
 523:     private static Year evaluateAsYear(String s) {
 524: 
 525:         Year result = null;
 526:         try {
 527:             result = Year.parseYear(s);
 528:         }
 529:         catch (TimePeriodFormatException e) {
 530:             // suppress
 531:         }
 532:         return result;
 533: 
 534:     }
 535: 
 536:     /**
 537:      * Converts a string to a week.
 538:      *
 539:      * @param s  the string to parse.
 540:      * @return <code>-1</code> if the string does not contain a week number,
 541:      *         the number of the week otherwise.
 542:      */
 543:     private static int stringToWeek(String s) {
 544: 
 545:         int result = -1;
 546:         s = s.replace('W', ' ');
 547:         s = s.trim();
 548:         try {
 549:             result = Integer.parseInt(s);
 550:             if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
 551:                 result = -1;
 552:             }
 553:         }
 554:         catch (NumberFormatException e) {
 555:             // suppress
 556:         }
 557:         return result;
 558: 
 559:     }
 560:     
 561: }