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:  * 19-Dec-2007 : Fixed bug in deprecated constructor (DG);
  69:  *
  70:  */
  71: 
  72: package org.jfree.data.time;
  73: 
  74: import java.io.Serializable;
  75: import java.util.Calendar;
  76: import java.util.Date;
  77: import java.util.Locale;
  78: import java.util.TimeZone;
  79: 
  80: /**
  81:  * A calendar week.  All years are considered to have 53 weeks, numbered from 1 
  82:  * to 53, although in many cases the 53rd week is empty.  Most of the time, the
  83:  * 1st week of the year *begins* in the previous calendar year, but it always 
  84:  * finishes in the current year (this behaviour matches the workings of the 
  85:  * <code>GregorianCalendar</code> class).
  86:  * <P>
  87:  * This class is immutable, which is a requirement for all 
  88:  * {@link RegularTimePeriod} subclasses.
  89:  */
  90: public class Week extends RegularTimePeriod implements Serializable {
  91: 
  92:     /** For serialization. */
  93:     private static final long serialVersionUID = 1856387786939865061L;
  94:     
  95:     /** Constant for the first week in the year. */
  96:     public static final int FIRST_WEEK_IN_YEAR = 1;
  97: 
  98:     /** Constant for the last week in the year. */
  99:     public static final int LAST_WEEK_IN_YEAR = 53;
 100: 
 101:     /** The year in which the week falls. */
 102:     private short year;
 103: 
 104:     /** The week (1-53). */
 105:     private byte week;
 106: 
 107:     /** The first millisecond. */
 108:     private long firstMillisecond;
 109:     
 110:     /** The last millisecond. */
 111:     private long lastMillisecond;
 112: 
 113:     /**
 114:      * Creates a new time period for the week in which the current system 
 115:      * date/time falls.
 116:      */
 117:     public Week() {
 118:         this(new Date());
 119:     }
 120: 
 121:     /**
 122:      * Creates a time period representing the week in the specified year.
 123:      *
 124:      * @param week  the week (1 to 53).
 125:      * @param year  the year (1900 to 9999).
 126:      */
 127:     public Week(int week, int year) {
 128:         if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
 129:             throw new IllegalArgumentException(
 130:                     "The 'week' argument must be in the range 1 - 53.");
 131:         }
 132:         this.week = (byte) week;
 133:         this.year = (short) year;
 134:         peg(Calendar.getInstance());
 135:     }
 136: 
 137:     /**
 138:      * Creates a time period representing the week in the specified year.
 139:      *
 140:      * @param week  the week (1 to 53).
 141:      * @param year  the year (1900 to 9999).
 142:      */
 143:     public Week(int week, Year year) {
 144:         if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
 145:             throw new IllegalArgumentException(
 146:                     "The 'week' argument must be in the range 1 - 53.");
 147:         }
 148:         this.week = (byte) week;
 149:         this.year = (short) year.getYear();
 150:         peg(Calendar.getInstance());
 151:    }
 152: 
 153:     /**
 154:      * Creates a time period for the week in which the specified date/time 
 155:      * falls.
 156:      *
 157:      * @param time  the time (<code>null</code> not permitted).
 158:      */
 159:     public Week(Date time) {
 160:         // defer argument checking...
 161:         this(time, RegularTimePeriod.DEFAULT_TIME_ZONE, Locale.getDefault());
 162:     }
 163: 
 164:     /**
 165:      * Creates a time period for the week in which the specified date/time 
 166:      * falls, calculated relative to the specified time zone.
 167:      *
 168:      * @param time  the date/time (<code>null</code> not permitted).
 169:      * @param zone  the time zone (<code>null</code> not permitted).
 170:      * 
 171:      * @deprecated As of 1.0.7, use {@link #Week(Date, TimeZone, Locale)}.
 172:      */
 173:     public Week(Date time, TimeZone zone) {
 174:         // defer argument checking...
 175:         this(time, zone, Locale.getDefault());
 176:     }
 177:     
 178:     /**
 179:      * Creates a time period for the week in which the specified date/time 
 180:      * falls, calculated relative to the specified time zone.
 181:      *
 182:      * @param time  the date/time (<code>null</code> not permitted).
 183:      * @param zone  the time zone (<code>null</code> not permitted).
 184:      * @param locale  the locale (<code>null</code> not permitted).
 185:      * 
 186:      * @since 1.0.7
 187:      */
 188:     public Week(Date time, TimeZone zone, Locale locale) {
 189:         if (time == null) {
 190:             throw new IllegalArgumentException("Null 'time' argument.");   
 191:         }
 192:         if (zone == null) {
 193:             throw new IllegalArgumentException("Null 'zone' argument.");   
 194:         }
 195:         if (locale == null) {
 196:             throw new IllegalArgumentException("Null 'locale' argument.");
 197:         }
 198:         Calendar calendar = Calendar.getInstance(zone, locale);
 199:         calendar.setTime(time);
 200: 
 201:         // sometimes the last few days of the year are considered to fall in 
 202:         // the *first* week of the following year.  Refer to the Javadocs for 
 203:         // GregorianCalendar.
 204:         int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
 205:         if (tempWeek == 1 
 206:                 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
 207:             this.week = 1;
 208:             this.year = (short) (calendar.get(Calendar.YEAR) + 1);
 209:         }
 210:         else {
 211:             this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
 212:             int yyyy = calendar.get(Calendar.YEAR);
 213:             // alternatively, sometimes the first few days of the year are
 214:             // considered to fall in the *last* week of the previous year...
 215:             if (calendar.get(Calendar.MONTH) == Calendar.JANUARY 
 216:                     && this.week >= 52) {
 217:                 yyyy--; 
 218:             }
 219:             this.year = (short) yyyy;
 220:         }
 221:         peg(calendar);
 222:     }
 223: 
 224:     /**
 225:      * Returns the year in which the week falls.
 226:      *
 227:      * @return The year (never <code>null</code>).
 228:      */
 229:     public Year getYear() {
 230:         return new Year(this.year);
 231:     }
 232: 
 233:     /**
 234:      * Returns the year in which the week falls, as an integer value.
 235:      *
 236:      * @return The year.
 237:      */
 238:     public int getYearValue() {
 239:         return this.year;
 240:     }
 241: 
 242:     /**
 243:      * Returns the week.
 244:      *
 245:      * @return The week.
 246:      */
 247:     public int getWeek() {
 248:         return this.week;
 249:     }
 250: 
 251:     /**
 252:      * Returns the first millisecond of the week.  This will be determined 
 253:      * relative to the time zone specified in the constructor, or in the 
 254:      * calendar instance passed in the most recent call to the 
 255:      * {@link #peg(Calendar)} method.
 256:      *
 257:      * @return The first millisecond of the week.
 258:      * 
 259:      * @see #getLastMillisecond()
 260:      */
 261:     public long getFirstMillisecond() {
 262:         return this.firstMillisecond;
 263:     }
 264: 
 265:     /**
 266:      * Returns the last millisecond of the week.  This will be 
 267:      * determined relative to the time zone specified in the constructor, or
 268:      * in the calendar instance passed in the most recent call to the 
 269:      * {@link #peg(Calendar)} method.
 270:      *
 271:      * @return The last millisecond of the week.
 272:      * 
 273:      * @see #getFirstMillisecond()
 274:      */
 275:     public long getLastMillisecond() {
 276:         return this.lastMillisecond;
 277:     }
 278:     
 279:     /** 
 280:      * Recalculates the start date/time and end date/time for this time period 
 281:      * relative to the supplied calendar (which incorporates a time zone).
 282:      * 
 283:      * @param calendar  the calendar (<code>null</code> not permitted).
 284:      * 
 285:      * @since 1.0.3
 286:      */
 287:     public void peg(Calendar calendar) {
 288:         this.firstMillisecond = getFirstMillisecond(calendar);
 289:         this.lastMillisecond = getLastMillisecond(calendar);
 290:     }
 291: 
 292:     /**
 293:      * Returns the week preceding this one.  This method will return 
 294:      * <code>null</code> for some lower limit on the range of weeks (currently 
 295:      * week 1, 1900).  For week 1 of any year, the previous week is always week 
 296:      * 53, but week 53 may not contain any days (you should check for this).
 297:      *
 298:      * @return The preceding week (possibly <code>null</code>).
 299:      */
 300:     public RegularTimePeriod previous() {
 301: 
 302:         Week result;
 303:         if (this.week != FIRST_WEEK_IN_YEAR) {
 304:             result = new Week(this.week - 1, this.year);
 305:         }
 306:         else {
 307:             // we need to work out if the previous year has 52 or 53 weeks...
 308:             if (this.year > 1900) {
 309:                 int yy = this.year - 1;
 310:                 Calendar prevYearCalendar = Calendar.getInstance();
 311:                 prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
 312:                 result = new Week(prevYearCalendar.getActualMaximum(
 313:                         Calendar.WEEK_OF_YEAR), yy);
 314:             }
 315:             else {
 316:                 result = null;
 317:             }
 318:         }
 319:         return result;
 320: 
 321:     }
 322: 
 323:     /**
 324:      * Returns the week following this one.  This method will return 
 325:      * <code>null</code> for some upper limit on the range of weeks (currently 
 326:      * week 53, 9999).  For week 52 of any year, the following week is always 
 327:      * week 53, but week 53 may not contain any days (you should check for 
 328:      * this).
 329:      *
 330:      * @return The following week (possibly <code>null</code>).
 331:      */
 332:     public RegularTimePeriod next() {
 333: 
 334:         Week result;
 335:         if (this.week < 52) {
 336:             result = new Week(this.week + 1, this.year);
 337:         }
 338:         else {
 339:             Calendar calendar = Calendar.getInstance();
 340:             calendar.set(this.year, Calendar.DECEMBER, 31);
 341:             int actualMaxWeek 
 342:                 = calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
 343:             if (this.week < actualMaxWeek) {
 344:                 result = new Week(this.week + 1, this.year);
 345:             }
 346:             else {
 347:                 if (this.year < 9999) {
 348:                     result = new Week(FIRST_WEEK_IN_YEAR, this.year + 1);
 349:                 }
 350:                 else {
 351:                     result = null;
 352:                 }
 353:             }
 354:         }
 355:         return result;
 356: 
 357:     }
 358: 
 359:     /**
 360:      * Returns a serial index number for the week.
 361:      *
 362:      * @return The serial index number.
 363:      */
 364:     public long getSerialIndex() {
 365:         return this.year * 53L + this.week;
 366:     }
 367: 
 368:     /**
 369:      * Returns the first millisecond of the week, evaluated using the supplied
 370:      * calendar (which determines the time zone).
 371:      *
 372:      * @param calendar  the calendar (<code>null</code> not permitted).
 373:      *
 374:      * @return The first millisecond of the week.
 375:      *
 376:      * @throws NullPointerException if <code>calendar</code> is 
 377:      *     <code>null</code>.
 378:      */
 379:     public long getFirstMillisecond(Calendar calendar) {
 380:         Calendar c = (Calendar) calendar.clone();
 381:         c.clear();
 382:         c.set(Calendar.YEAR, this.year);
 383:         c.set(Calendar.WEEK_OF_YEAR, this.week);
 384:         c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
 385:         c.set(Calendar.HOUR, 0);
 386:         c.set(Calendar.MINUTE, 0);
 387:         c.set(Calendar.SECOND, 0);
 388:         c.set(Calendar.MILLISECOND, 0);
 389:         //return c.getTimeInMillis();  // this won't work for JDK 1.3
 390:         return c.getTime().getTime();
 391:     }
 392: 
 393:     /**
 394:      * Returns the last millisecond of the week, evaluated using the supplied
 395:      * calendar (which determines the time zone).
 396:      *
 397:      * @param calendar  the calendar (<code>null</code> not permitted).
 398:      *
 399:      * @return The last millisecond of the week.
 400:      *
 401:      * @throws NullPointerException if <code>calendar</code> is 
 402:      *     <code>null</code>.
 403:      */
 404:     public long getLastMillisecond(Calendar calendar) {
 405:         Calendar c = (Calendar) calendar.clone();
 406:         c.clear();
 407:         c.set(Calendar.YEAR, this.year);
 408:         c.set(Calendar.WEEK_OF_YEAR, this.week + 1);
 409:         c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
 410:         c.set(Calendar.HOUR, 0);
 411:         c.set(Calendar.MINUTE, 0);
 412:         c.set(Calendar.SECOND, 0);
 413:         c.set(Calendar.MILLISECOND, 0);
 414:         //return c.getTimeInMillis();  // this won't work for JDK 1.3
 415:         return c.getTime().getTime() - 1;
 416:     }
 417: 
 418:     /**
 419:      * Returns a string representing the week (e.g. "Week 9, 2002").
 420:      *
 421:      * TODO: look at internationalisation.
 422:      *
 423:      * @return A string representing the week.
 424:      */
 425:     public String toString() {
 426:         return "Week " + this.week + ", " + this.year;
 427:     }
 428: 
 429:     /**
 430:      * Tests the equality of this Week object to an arbitrary object.  Returns
 431:      * true if the target is a Week instance representing the same week as this
 432:      * object.  In all other cases, returns false.
 433:      *
 434:      * @param obj  the object (<code>null</code> permitted).
 435:      *
 436:      * @return <code>true</code> if week and year of this and object are the 
 437:      *         same.
 438:      */
 439:     public boolean equals(Object obj) {
 440: 
 441:         if (obj == this) {
 442:             return true;
 443:         }
 444:         if (!(obj instanceof Week)) {
 445:             return false;
 446:         }
 447:         Week that = (Week) obj;
 448:         if (this.week != that.week) {
 449:             return false;
 450:         }
 451:         if (this.year != that.year) {
 452:             return false;
 453:         }
 454:         return true;
 455: 
 456:     }
 457: 
 458:     /**
 459:      * Returns a hash code for this object instance.  The approach described by
 460:      * Joshua Bloch in "Effective Java" has been used here:
 461:      * <p>
 462:      * <code>http://developer.java.sun.com/developer/Books/effectivejava
 463:      * /Chapter3.pdf</code>
 464:      * 
 465:      * @return A hash code.
 466:      */
 467:     public int hashCode() {
 468:         int result = 17;
 469:         result = 37 * result + this.week;
 470:         result = 37 * result + this.year;
 471:         return result;
 472:     }
 473: 
 474:     /**
 475:      * Returns an integer indicating the order of this Week object relative to
 476:      * the specified object:
 477:      *
 478:      * negative == before, zero == same, positive == after.
 479:      *
 480:      * @param o1  the object to compare.
 481:      *
 482:      * @return negative == before, zero == same, positive == after.
 483:      */
 484:     public int compareTo(Object o1) {
 485: 
 486:         int result;
 487: 
 488:         // CASE 1 : Comparing to another Week object
 489:         // --------------------------------------------
 490:         if (o1 instanceof Week) {
 491:             Week w = (Week) o1;
 492:             result = this.year - w.getYear().getYear();
 493:             if (result == 0) {
 494:                 result = this.week - w.getWeek();
 495:             }
 496:         }
 497: 
 498:         // CASE 2 : Comparing to another TimePeriod object
 499:         // -----------------------------------------------
 500:         else if (o1 instanceof RegularTimePeriod) {
 501:             // more difficult case - evaluate later...
 502:             result = 0;
 503:         }
 504: 
 505:         // CASE 3 : Comparing to a non-TimePeriod object
 506:         // ---------------------------------------------
 507:         else {
 508:             // consider time periods to be ordered after general objects
 509:             result = 1;
 510:         }
 511: 
 512:         return result;
 513: 
 514:     }
 515: 
 516:     /**
 517:      * Parses the string argument as a week.
 518:      * <P>
 519:      * This method is required to accept the format "YYYY-Wnn".  It will also
 520:      * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
 521:      *
 522:      * @param s  string to parse.
 523:      *
 524:      * @return <code>null</code> if the string is not parseable, the week 
 525:      *         otherwise.
 526:      */
 527:     public static Week parseWeek(String s) {
 528: 
 529:         Week result = null;
 530:         if (s != null) {
 531: 
 532:             // trim whitespace from either end of the string
 533:             s = s.trim();
 534: 
 535:             int i = Week.findSeparator(s);
 536:             if (i != -1) {
 537:                 String s1 = s.substring(0, i).trim();
 538:                 String s2 = s.substring(i + 1, s.length()).trim();
 539: 
 540:                 Year y = Week.evaluateAsYear(s1);
 541:                 int w;
 542:                 if (y != null) {
 543:                     w = Week.stringToWeek(s2);
 544:                     if (w == -1) {
 545:                         throw new TimePeriodFormatException(
 546:                                 "Can't evaluate the week.");
 547:                     }
 548:                     result = new Week(w, y);
 549:                 }
 550:                 else {
 551:                     y = Week.evaluateAsYear(s2);
 552:                     if (y != null) {
 553:                         w = Week.stringToWeek(s1);
 554:                         if (w == -1) {
 555:                             throw new TimePeriodFormatException(
 556:                                     "Can't evaluate the week.");
 557:                         }
 558:                         result = new Week(w, y);
 559:                     }
 560:                     else {
 561:                         throw new TimePeriodFormatException(
 562:                                 "Can't evaluate the year.");
 563:                     }
 564:                 }
 565: 
 566:             }
 567:             else {
 568:                 throw new TimePeriodFormatException(
 569:                         "Could not find separator.");
 570:             }
 571: 
 572:         }
 573:         return result;
 574: 
 575:     }
 576: 
 577:     /**
 578:      * Finds the first occurrence of ' ', '-', ',' or '.'
 579:      *
 580:      * @param s  the string to parse.
 581:      *
 582:      * @return <code>-1</code> if none of the characters was found, the
 583:      *      index of the first occurrence otherwise.
 584:      */
 585:     private static int findSeparator(String s) {
 586: 
 587:         int result = s.indexOf('-');
 588:         if (result == -1) {
 589:             result = s.indexOf(',');
 590:         }
 591:         if (result == -1) {
 592:             result = s.indexOf(' ');
 593:         }
 594:         if (result == -1) {
 595:             result = s.indexOf('.');
 596:         }
 597:         return result;
 598:     }
 599: 
 600:     /**
 601:      * Creates a year from a string, or returns null (format exceptions
 602:      * suppressed).
 603:      *
 604:      * @param s  string to parse.
 605:      *
 606:      * @return <code>null</code> if the string is not parseable, the year 
 607:      *         otherwise.
 608:      */
 609:     private static Year evaluateAsYear(String s) {
 610: 
 611:         Year result = null;
 612:         try {
 613:             result = Year.parseYear(s);
 614:         }
 615:         catch (TimePeriodFormatException e) {
 616:             // suppress
 617:         }
 618:         return result;
 619: 
 620:     }
 621: 
 622:     /**
 623:      * Converts a string to a week.
 624:      *
 625:      * @param s  the string to parse.
 626:      * @return <code>-1</code> if the string does not contain a week number,
 627:      *         the number of the week otherwise.
 628:      */
 629:     private static int stringToWeek(String s) {
 630: 
 631:         int result = -1;
 632:         s = s.replace('W', ' ');
 633:         s = s.trim();
 634:         try {
 635:             result = Integer.parseInt(s);
 636:             if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
 637:                 result = -1;
 638:             }
 639:         }
 640:         catch (NumberFormatException e) {
 641:             // suppress
 642:         }
 643:         return result;
 644: 
 645:     }
 646:     
 647: }