Source for org.jfree.data.time.Week

   1: /* ===========================================================
   2:  * JFreeChart : a free chart library for the Java(tm) platform
   3:  * ===========================================================
   4:  *
   5:  * (C) Copyright 2000-2007, 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 2001-2007, by Object Refinery Limited and Contributors.
  31:  *
  32:  * Original Author:  David Gilbert (for Object Refinery Limited);
  33:  * Contributor(s):   Aimin Han;
  34:  *
  35:  * Changes
  36:  * -------
  37:  * 11-Oct-2001 : Version 1 (DG);
  38:  * 18-Dec-2001 : Changed order of parameters in constructor (DG);
  39:  * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
  40:  * 29-Jan-2002 : Worked on the parseWeek() method (DG);
  41:  * 13-Feb-2002 : Fixed bug in Week(Date) constructor (DG);
  42:  * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to 
  43:  *               evaluate with reference to a particular time zone (DG);
  44:  * 05-Apr-2002 : Reinstated this class to the JCommon library (DG);
  45:  * 24-Jun-2002 : Removed unnecessary main method (DG);
  46:  * 10-Sep-2002 : Added getSerialIndex() method (DG);
  47:  * 06-Oct-2002 : Fixed errors reported by Checkstyle (DG);
  48:  * 18-Oct-2002 : Changed to observe 52 or 53 weeks per year, consistent with 
  49:  *               GregorianCalendar. Thanks to Aimin Han for the code (DG);
  50:  * 02-Jan-2003 : Removed debug code (DG);
  51:  * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented 
  52:  *               Serializable (DG);
  53:  * 21-Oct-2003 : Added hashCode() method (DG);
  54:  * 24-May-2004 : Modified getFirstMillisecond() and getLastMillisecond() to 
  55:  *               take account of firstDayOfWeek setting in Java's Calendar 
  56:  *               class (DG);
  57:  * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
  58:  * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for 
  59:  *               JDK 1.3 (DG);
  60:  * ------------- JFREECHART 1.0.x ---------------------------------------------
  61:  * 06-Mar-2006 : Fix for bug 1448828, incorrect calculation of week and year
  62:  *               for the first few days of some years (DG);
  63:  * 05-Oct-2006 : Updated API docs (DG);
  64:  * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
  65:  * 09-Jan-2007 : Fixed bug in next() (DG);
  66:  * 28-Aug-2007 : Added new constructor to avoid problem in creating new 
  67:  *               instances (DG);
  68:  *
  69:  */
  70: 
  71: package org.jfree.data.time;
  72: 
  73: import java.io.Serializable;
  74: import java.util.Calendar;
  75: import java.util.Date;
  76: import java.util.Locale;
  77: import java.util.TimeZone;
  78: 
  79: /**
  80:  * A calendar week.  All years are considered to have 53 weeks, numbered from 1 
  81:  * to 53, although in many cases the 53rd week is empty.  Most of the time, the
  82:  * 1st week of the year *begins* in the previous calendar year, but it always 
  83:  * finishes in the current year (this behaviour matches the workings of the 
  84:  * <code>GregorianCalendar</code> class).
  85:  * <P>
  86:  * This class is immutable, which is a requirement for all 
  87:  * {@link RegularTimePeriod} subclasses.
  88:  */
  89: public class Week extends RegularTimePeriod implements Serializable {
  90: 
  91:     /** For serialization. */
  92:     private static final long serialVersionUID = 1856387786939865061L;
  93:     
  94:     /** Constant for the first week in the year. */
  95:     public static final int FIRST_WEEK_IN_YEAR = 1;
  96: 
  97:     /** Constant for the last week in the year. */
  98:     public static final int LAST_WEEK_IN_YEAR = 53;
  99: 
 100:     /** The year in which the week falls. */
 101:     private short year;
 102: 
 103:     /** The week (1-53). */
 104:     private byte week;
 105: 
 106:     /** The first millisecond. */
 107:     private long firstMillisecond;
 108:     
 109:     /** The last millisecond. */
 110:     private long lastMillisecond;
 111: 
 112:     /**
 113:      * Creates a new time period for the week in which the current system 
 114:      * date/time falls.
 115:      */
 116:     public Week() {
 117:         this(new Date());
 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, int 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:         this.week = (byte) week;
 132:         this.year = (short) year;
 133:         peg(Calendar.getInstance());
 134:     }
 135: 
 136:     /**
 137:      * Creates a time period representing the week in the specified year.
 138:      *
 139:      * @param week  the week (1 to 53).
 140:      * @param year  the year (1900 to 9999).
 141:      */
 142:     public Week(int week, Year year) {
 143:         if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
 144:             throw new IllegalArgumentException(
 145:                     "The 'week' argument must be in the range 1 - 53.");
 146:         }
 147:         this.week = (byte) week;
 148:         this.year = (short) year.getYear();
 149:         peg(Calendar.getInstance());
 150:    }
 151: 
 152:     /**
 153:      * Creates a time period for the week in which the specified date/time 
 154:      * falls.
 155:      *
 156:      * @param time  the time (<code>null</code> not permitted).
 157:      */
 158:     public Week(Date time) {
 159:         // defer argument checking...
 160:         this(time, RegularTimePeriod.DEFAULT_TIME_ZONE, Locale.getDefault());
 161:     }
 162: 
 163:     /**
 164:      * Creates a time period for the week in which the specified date/time 
 165:      * falls, calculated relative to the specified time zone.
 166:      *
 167:      * @param time  the date/time (<code>null</code> not permitted).
 168:      * @param zone  the time zone (<code>null</code> not permitted).
 169:      * 
 170:      * @deprecated As of 1.0.7, use {@link #Week(Date, TimeZone, Locale)}.
 171:      */
 172:     public Week(Date time, TimeZone zone) {
 173:         // defer argument checking...
 174:         this(time, RegularTimePeriod.DEFAULT_TIME_ZONE, Locale.getDefault());
 175:     }
 176:     
 177:     /**
 178:      * Creates a time period for the week in which the specified date/time 
 179:      * falls, calculated relative to the specified time zone.
 180:      *
 181:      * @param time  the date/time (<code>null</code> not permitted).
 182:      * @param zone  the time zone (<code>null</code> not permitted).
 183:      * @param locale  the locale (<code>null</code> not permitted).
 184:      * 
 185:      * @since 1.0.7
 186:      */
 187:     public Week(Date time, TimeZone zone, Locale locale) {
 188:         if (time == null) {
 189:             throw new IllegalArgumentException("Null 'time' argument.");   
 190:         }
 191:         if (zone == null) {
 192:             throw new IllegalArgumentException("Null 'zone' argument.");   
 193:         }
 194:         if (locale == null) {
 195:             throw new IllegalArgumentException("Null 'locale' argument.");
 196:         }
 197:         Calendar calendar = Calendar.getInstance(zone, locale);
 198:         calendar.setTime(time);
 199: 
 200:         // sometimes the last few days of the year are considered to fall in 
 201:         // the *first* week of the following year.  Refer to the Javadocs for 
 202:         // GregorianCalendar.
 203:         int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
 204:         if (tempWeek == 1 
 205:                 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
 206:             this.week = 1;
 207:             this.year = (short) (calendar.get(Calendar.YEAR) + 1);
 208:         }
 209:         else {
 210:             this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
 211:             int yyyy = calendar.get(Calendar.YEAR);
 212:             // alternatively, sometimes the first few days of the year are
 213:             // considered to fall in the *last* week of the previous year...
 214:             if (calendar.get(Calendar.MONTH) == Calendar.JANUARY 
 215:                     && this.week >= 52) {
 216:                 yyyy--; 
 217:             }
 218:             this.year = (short) yyyy;
 219:         }
 220:         peg(calendar);
 221:     }
 222: 
 223:     /**
 224:      * Returns the year in which the week falls.
 225:      *
 226:      * @return The year (never <code>null</code>).
 227:      */
 228:     public Year getYear() {
 229:         return new Year(this.year);
 230:     }
 231: 
 232:     /**
 233:      * Returns the year in which the week falls, as an integer value.
 234:      *
 235:      * @return The year.
 236:      */
 237:     public int getYearValue() {
 238:         return this.year;
 239:     }
 240: 
 241:     /**
 242:      * Returns the week.
 243:      *
 244:      * @return The week.
 245:      */
 246:     public int getWeek() {
 247:         return this.week;
 248:     }
 249: 
 250:     /**
 251:      * Returns the first millisecond of the week.  This will be determined 
 252:      * relative to the time zone specified in the constructor, or in the 
 253:      * calendar instance passed in the most recent call to the 
 254:      * {@link #peg(Calendar)} method.
 255:      *
 256:      * @return The first millisecond of the week.
 257:      * 
 258:      * @see #getLastMillisecond()
 259:      */
 260:     public long getFirstMillisecond() {
 261:         return this.firstMillisecond;
 262:     }
 263: 
 264:     /**
 265:      * Returns the last millisecond of the week.  This will be 
 266:      * determined relative to the time zone specified in the constructor, or
 267:      * in the calendar instance passed in the most recent call to the 
 268:      * {@link #peg(Calendar)} method.
 269:      *
 270:      * @return The last millisecond of the week.
 271:      * 
 272:      * @see #getFirstMillisecond()
 273:      */
 274:     public long getLastMillisecond() {
 275:         return this.lastMillisecond;
 276:     }
 277:     
 278:     /** 
 279:      * Recalculates the start date/time and end date/time for this time period 
 280:      * relative to the supplied calendar (which incorporates a time zone).
 281:      * 
 282:      * @param calendar  the calendar (<code>null</code> not permitted).
 283:      * 
 284:      * @since 1.0.3
 285:      */
 286:     public void peg(Calendar calendar) {
 287:         this.firstMillisecond = getFirstMillisecond(calendar);
 288:         this.lastMillisecond = getLastMillisecond(calendar);
 289:     }
 290: 
 291:     /**
 292:      * Returns the week preceding this one.  This method will return 
 293:      * <code>null</code> for some lower limit on the range of weeks (currently 
 294:      * week 1, 1900).  For week 1 of any year, the previous week is always week 
 295:      * 53, but week 53 may not contain any days (you should check for this).
 296:      *
 297:      * @return The preceding week (possibly <code>null</code>).
 298:      */
 299:     public RegularTimePeriod previous() {
 300: 
 301:         Week result;
 302:         if (this.week != FIRST_WEEK_IN_YEAR) {
 303:             result = new Week(this.week - 1, this.year);
 304:         }
 305:         else {
 306:             // we need to work out if the previous year has 52 or 53 weeks...
 307:             if (this.year > 1900) {
 308:                 int yy = this.year - 1;
 309:                 Calendar prevYearCalendar = Calendar.getInstance();
 310:                 prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
 311:                 result = new Week(prevYearCalendar.getActualMaximum(
 312:                         Calendar.WEEK_OF_YEAR), yy);
 313:             }
 314:             else {
 315:                 result = null;
 316:             }
 317:         }
 318:         return result;
 319: 
 320:     }
 321: 
 322:     /**
 323:      * Returns the week following this one.  This method will return 
 324:      * <code>null</code> for some upper limit on the range of weeks (currently 
 325:      * week 53, 9999).  For week 52 of any year, the following week is always 
 326:      * week 53, but week 53 may not contain any days (you should check for 
 327:      * this).
 328:      *
 329:      * @return The following week (possibly <code>null</code>).
 330:      */
 331:     public RegularTimePeriod next() {
 332: 
 333:         Week result;
 334:         if (this.week < 52) {
 335:             result = new Week(this.week + 1, this.year);
 336:         }
 337:         else {
 338:             Calendar calendar = Calendar.getInstance();
 339:             calendar.set(this.year, Calendar.DECEMBER, 31);
 340:             int actualMaxWeek 
 341:                 = calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
 342:             if (this.week < actualMaxWeek) {
 343:                 result = new Week(this.week + 1, this.year);
 344:             }
 345:             else {
 346:                 if (this.year < 9999) {
 347:                     result = new Week(FIRST_WEEK_IN_YEAR, this.year + 1);
 348:                 }
 349:                 else {
 350:                     result = null;
 351:                 }
 352:             }
 353:         }
 354:         return result;
 355: 
 356:     }
 357: 
 358:     /**
 359:      * Returns a serial index number for the week.
 360:      *
 361:      * @return The serial index number.
 362:      */
 363:     public long getSerialIndex() {
 364:         return this.year * 53L + this.week;
 365:     }
 366: 
 367:     /**
 368:      * Returns the first millisecond of the week, evaluated using the supplied
 369:      * calendar (which determines the time zone).
 370:      *
 371:      * @param calendar  the calendar (<code>null</code> not permitted).
 372:      *
 373:      * @return The first millisecond of the week.
 374:      *
 375:      * @throws NullPointerException if <code>calendar</code> is 
 376:      *     <code>null</code>.
 377:      */
 378:     public long getFirstMillisecond(Calendar calendar) {
 379:         Calendar c = (Calendar) calendar.clone();
 380:         c.clear();
 381:         c.set(Calendar.YEAR, this.year);
 382:         c.set(Calendar.WEEK_OF_YEAR, this.week);
 383:         c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
 384:         c.set(Calendar.HOUR, 0);
 385:         c.set(Calendar.MINUTE, 0);
 386:         c.set(Calendar.SECOND, 0);
 387:         c.set(Calendar.MILLISECOND, 0);
 388:         //return c.getTimeInMillis();  // this won't work for JDK 1.3
 389:         return c.getTime().getTime();
 390:     }
 391: 
 392:     /**
 393:      * Returns the last millisecond of the week, evaluated using the supplied
 394:      * calendar (which determines the time zone).
 395:      *
 396:      * @param calendar  the calendar (<code>null</code> not permitted).
 397:      *
 398:      * @return The last millisecond of the week.
 399:      *
 400:      * @throws NullPointerException if <code>calendar</code> is 
 401:      *     <code>null</code>.
 402:      */
 403:     public long getLastMillisecond(Calendar calendar) {
 404:         Calendar c = (Calendar) calendar.clone();
 405:         c.clear();
 406:         c.set(Calendar.YEAR, this.year);
 407:         c.set(Calendar.WEEK_OF_YEAR, this.week + 1);
 408:         c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
 409:         c.set(Calendar.HOUR, 0);
 410:         c.set(Calendar.MINUTE, 0);
 411:         c.set(Calendar.SECOND, 0);
 412:         c.set(Calendar.MILLISECOND, 0);
 413:         //return c.getTimeInMillis();  // this won't work for JDK 1.3
 414:         return c.getTime().getTime() - 1;
 415:     }
 416: 
 417:     /**
 418:      * Returns a string representing the week (e.g. "Week 9, 2002").
 419:      *
 420:      * TODO: look at internationalisation.
 421:      *
 422:      * @return A string representing the week.
 423:      */
 424:     public String toString() {
 425:         return "Week " + this.week + ", " + this.year;
 426:     }
 427: 
 428:     /**
 429:      * Tests the equality of this Week object to an arbitrary object.  Returns
 430:      * true if the target is a Week instance representing the same week as this
 431:      * object.  In all other cases, returns false.
 432:      *
 433:      * @param obj  the object (<code>null</code> permitted).
 434:      *
 435:      * @return <code>true</code> if week and year of this and object are the 
 436:      *         same.
 437:      */
 438:     public boolean equals(Object obj) {
 439: 
 440:         if (obj == this) {
 441:             return true;
 442:         }
 443:         if (!(obj instanceof Week)) {
 444:             return false;
 445:         }
 446:         Week that = (Week) obj;
 447:         if (this.week != that.week) {
 448:             return false;
 449:         }
 450:         if (this.year != that.year) {
 451:             return false;
 452:         }
 453:         return true;
 454: 
 455:     }
 456: 
 457:     /**
 458:      * Returns a hash code for this object instance.  The approach described by
 459:      * Joshua Bloch in "Effective Java" has been used here:
 460:      * <p>
 461:      * <code>http://developer.java.sun.com/developer/Books/effectivejava
 462:      * /Chapter3.pdf</code>
 463:      * 
 464:      * @return A hash code.
 465:      */
 466:     public int hashCode() {
 467:         int result = 17;
 468:         result = 37 * result + this.week;
 469:         result = 37 * result + this.year;
 470:         return result;
 471:     }
 472: 
 473:     /**
 474:      * Returns an integer indicating the order of this Week object relative to
 475:      * the specified object:
 476:      *
 477:      * negative == before, zero == same, positive == after.
 478:      *
 479:      * @param o1  the object to compare.
 480:      *
 481:      * @return negative == before, zero == same, positive == after.
 482:      */
 483:     public int compareTo(Object o1) {
 484: 
 485:         int result;
 486: 
 487:         // CASE 1 : Comparing to another Week object
 488:         // --------------------------------------------
 489:         if (o1 instanceof Week) {
 490:             Week w = (Week) o1;
 491:             result = this.year - w.getYear().getYear();
 492:             if (result == 0) {
 493:                 result = this.week - w.getWeek();
 494:             }
 495:         }
 496: 
 497:         // CASE 2 : Comparing to another TimePeriod object
 498:         // -----------------------------------------------
 499:         else if (o1 instanceof RegularTimePeriod) {
 500:             // more difficult case - evaluate later...
 501:             result = 0;
 502:         }
 503: 
 504:         // CASE 3 : Comparing to a non-TimePeriod object
 505:         // ---------------------------------------------
 506:         else {
 507:             // consider time periods to be ordered after general objects
 508:             result = 1;
 509:         }
 510: 
 511:         return result;
 512: 
 513:     }
 514: 
 515:     /**
 516:      * Parses the string argument as a week.
 517:      * <P>
 518:      * This method is required to accept the format "YYYY-Wnn".  It will also
 519:      * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
 520:      *
 521:      * @param s  string to parse.
 522:      *
 523:      * @return <code>null</code> if the string is not parseable, the week 
 524:      *         otherwise.
 525:      */
 526:     public static Week parseWeek(String s) {
 527: 
 528:         Week result = null;
 529:         if (s != null) {
 530: 
 531:             // trim whitespace from either end of the string
 532:             s = s.trim();
 533: 
 534:             int i = Week.findSeparator(s);
 535:             if (i != -1) {
 536:                 String s1 = s.substring(0, i).trim();
 537:                 String s2 = s.substring(i + 1, s.length()).trim();
 538: 
 539:                 Year y = Week.evaluateAsYear(s1);
 540:                 int w;
 541:                 if (y != null) {
 542:                     w = Week.stringToWeek(s2);
 543:                     if (w == -1) {
 544:                         throw new TimePeriodFormatException(
 545:                                 "Can't evaluate the week.");
 546:                     }
 547:                     result = new Week(w, y);
 548:                 }
 549:                 else {
 550:                     y = Week.evaluateAsYear(s2);
 551:                     if (y != null) {
 552:                         w = Week.stringToWeek(s1);
 553:                         if (w == -1) {
 554:                             throw new TimePeriodFormatException(
 555:                                     "Can't evaluate the week.");
 556:                         }
 557:                         result = new Week(w, y);
 558:                     }
 559:                     else {
 560:                         throw new TimePeriodFormatException(
 561:                                 "Can't evaluate the year.");
 562:                     }
 563:                 }
 564: 
 565:             }
 566:             else {
 567:                 throw new TimePeriodFormatException(
 568:                         "Could not find separator.");
 569:             }
 570: 
 571:         }
 572:         return result;
 573: 
 574:     }
 575: 
 576:     /**
 577:      * Finds the first occurrence of ' ', '-', ',' or '.'
 578:      *
 579:      * @param s  the string to parse.
 580:      *
 581:      * @return <code>-1</code> if none of the characters was found, the
 582:      *      index of the first occurrence otherwise.
 583:      */
 584:     private static int findSeparator(String s) {
 585: 
 586:         int result = s.indexOf('-');
 587:         if (result == -1) {
 588:             result = s.indexOf(',');
 589:         }
 590:         if (result == -1) {
 591:             result = s.indexOf(' ');
 592:         }
 593:         if (result == -1) {
 594:             result = s.indexOf('.');
 595:         }
 596:         return result;
 597:     }
 598: 
 599:     /**
 600:      * Creates a year from a string, or returns null (format exceptions
 601:      * suppressed).
 602:      *
 603:      * @param s  string to parse.
 604:      *
 605:      * @return <code>null</code> if the string is not parseable, the year 
 606:      *         otherwise.
 607:      */
 608:     private static Year evaluateAsYear(String s) {
 609: 
 610:         Year result = null;
 611:         try {
 612:             result = Year.parseYear(s);
 613:         }
 614:         catch (TimePeriodFormatException e) {
 615:             // suppress
 616:         }
 617:         return result;
 618: 
 619:     }
 620: 
 621:     /**
 622:      * Converts a string to a week.
 623:      *
 624:      * @param s  the string to parse.
 625:      * @return <code>-1</code> if the string does not contain a week number,
 626:      *         the number of the week otherwise.
 627:      */
 628:     private static int stringToWeek(String s) {
 629: 
 630:         int result = -1;
 631:         s = s.replace('W', ' ');
 632:         s = s.trim();
 633:         try {
 634:             result = Integer.parseInt(s);
 635:             if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
 636:                 result = -1;
 637:             }
 638:         }
 639:         catch (NumberFormatException e) {
 640:             // suppress
 641:         }
 642:         return result;
 643: 
 644:     }
 645:     
 646: }