001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ---------
028 * Week.java
029 * ---------
030 * (C) Copyright 2001-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): Aimin Han;
034 *
035 * Changes
036 * -------
037 * 11-Oct-2001 : Version 1 (DG);
038 * 18-Dec-2001 : Changed order of parameters in constructor (DG);
039 * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
040 * 29-Jan-2002 : Worked on the parseWeek() method (DG);
041 * 13-Feb-2002 : Fixed bug in Week(Date) constructor (DG);
042 * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to
043 * evaluate with reference to a particular time zone (DG);
044 * 05-Apr-2002 : Reinstated this class to the JCommon library (DG);
045 * 24-Jun-2002 : Removed unnecessary main method (DG);
046 * 10-Sep-2002 : Added getSerialIndex() method (DG);
047 * 06-Oct-2002 : Fixed errors reported by Checkstyle (DG);
048 * 18-Oct-2002 : Changed to observe 52 or 53 weeks per year, consistent with
049 * GregorianCalendar. Thanks to Aimin Han for the code (DG);
050 * 02-Jan-2003 : Removed debug code (DG);
051 * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented
052 * Serializable (DG);
053 * 21-Oct-2003 : Added hashCode() method (DG);
054 * 24-May-2004 : Modified getFirstMillisecond() and getLastMillisecond() to
055 * take account of firstDayOfWeek setting in Java's Calendar
056 * class (DG);
057 * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
058 * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for
059 * JDK 1.3 (DG);
060 * ------------- JFREECHART 1.0.x ---------------------------------------------
061 * 06-Mar-2006 : Fix for bug 1448828, incorrect calculation of week and year
062 * for the first few days of some years (DG);
063 * 05-Oct-2006 : Updated API docs (DG);
064 * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
065 * 09-Jan-2007 : Fixed bug in next() (DG);
066 * 28-Aug-2007 : Added new constructor to avoid problem in creating new
067 * instances (DG);
068 * 19-Dec-2007 : Fixed bug in deprecated constructor (DG);
069 * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE (DG);
070 *
071 */
072
073 package org.jfree.data.time;
074
075 import java.io.Serializable;
076 import java.util.Calendar;
077 import java.util.Date;
078 import java.util.Locale;
079 import java.util.TimeZone;
080
081 /**
082 * A calendar week. All years are considered to have 53 weeks, numbered from 1
083 * to 53, although in many cases the 53rd week is empty. Most of the time, the
084 * 1st week of the year *begins* in the previous calendar year, but it always
085 * finishes in the current year (this behaviour matches the workings of the
086 * <code>GregorianCalendar</code> class).
087 * <P>
088 * This class is immutable, which is a requirement for all
089 * {@link RegularTimePeriod} subclasses.
090 */
091 public class Week extends RegularTimePeriod implements Serializable {
092
093 /** For serialization. */
094 private static final long serialVersionUID = 1856387786939865061L;
095
096 /** Constant for the first week in the year. */
097 public static final int FIRST_WEEK_IN_YEAR = 1;
098
099 /** Constant for the last week in the year. */
100 public static final int LAST_WEEK_IN_YEAR = 53;
101
102 /** The year in which the week falls. */
103 private short year;
104
105 /** The week (1-53). */
106 private byte week;
107
108 /** The first millisecond. */
109 private long firstMillisecond;
110
111 /** The last millisecond. */
112 private long lastMillisecond;
113
114 /**
115 * Creates a new time period for the week in which the current system
116 * date/time falls.
117 */
118 public Week() {
119 this(new Date());
120 }
121
122 /**
123 * Creates a time period representing the week in the specified year.
124 *
125 * @param week the week (1 to 53).
126 * @param year the year (1900 to 9999).
127 */
128 public Week(int week, int year) {
129 if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
130 throw new IllegalArgumentException(
131 "The 'week' argument must be in the range 1 - 53.");
132 }
133 this.week = (byte) week;
134 this.year = (short) year;
135 peg(Calendar.getInstance());
136 }
137
138 /**
139 * Creates a time period representing the week in the specified year.
140 *
141 * @param week the week (1 to 53).
142 * @param year the year (1900 to 9999).
143 */
144 public Week(int week, Year year) {
145 if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
146 throw new IllegalArgumentException(
147 "The 'week' argument must be in the range 1 - 53.");
148 }
149 this.week = (byte) week;
150 this.year = (short) year.getYear();
151 peg(Calendar.getInstance());
152 }
153
154 /**
155 * Creates a time period for the week in which the specified date/time
156 * falls, using the default time zone and locale (the locale can affect the
157 * day-of-the-week that marks the beginning of the week, as well as the
158 * minimal number of days in the first week of the year).
159 *
160 * @param time the time (<code>null</code> not permitted).
161 *
162 * @see #Week(Date, TimeZone, Locale)
163 */
164 public Week(Date time) {
165 // defer argument checking...
166 this(time, TimeZone.getDefault(), Locale.getDefault());
167 }
168
169 /**
170 * Creates a time period for the week in which the specified date/time
171 * falls, calculated relative to the specified time zone.
172 *
173 * @param time the date/time (<code>null</code> not permitted).
174 * @param zone the time zone (<code>null</code> not permitted).
175 *
176 * @deprecated As of 1.0.7, use {@link #Week(Date, TimeZone, Locale)}.
177 */
178 public Week(Date time, TimeZone zone) {
179 // defer argument checking...
180 this(time, zone, Locale.getDefault());
181 }
182
183 /**
184 * Creates a time period for the week in which the specified date/time
185 * falls, calculated relative to the specified time zone.
186 *
187 * @param time the date/time (<code>null</code> not permitted).
188 * @param zone the time zone (<code>null</code> not permitted).
189 * @param locale the locale (<code>null</code> not permitted).
190 *
191 * @since 1.0.7
192 */
193 public Week(Date time, TimeZone zone, Locale locale) {
194 if (time == null) {
195 throw new IllegalArgumentException("Null 'time' argument.");
196 }
197 if (zone == null) {
198 throw new IllegalArgumentException("Null 'zone' argument.");
199 }
200 if (locale == null) {
201 throw new IllegalArgumentException("Null 'locale' argument.");
202 }
203 Calendar calendar = Calendar.getInstance(zone, locale);
204 calendar.setTime(time);
205
206 // sometimes the last few days of the year are considered to fall in
207 // the *first* week of the following year. Refer to the Javadocs for
208 // GregorianCalendar.
209 int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
210 if (tempWeek == 1
211 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
212 this.week = 1;
213 this.year = (short) (calendar.get(Calendar.YEAR) + 1);
214 }
215 else {
216 this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
217 int yyyy = calendar.get(Calendar.YEAR);
218 // alternatively, sometimes the first few days of the year are
219 // considered to fall in the *last* week of the previous year...
220 if (calendar.get(Calendar.MONTH) == Calendar.JANUARY
221 && this.week >= 52) {
222 yyyy--;
223 }
224 this.year = (short) yyyy;
225 }
226 peg(calendar);
227 }
228
229 /**
230 * Returns the year in which the week falls.
231 *
232 * @return The year (never <code>null</code>).
233 */
234 public Year getYear() {
235 return new Year(this.year);
236 }
237
238 /**
239 * Returns the year in which the week falls, as an integer value.
240 *
241 * @return The year.
242 */
243 public int getYearValue() {
244 return this.year;
245 }
246
247 /**
248 * Returns the week.
249 *
250 * @return The week.
251 */
252 public int getWeek() {
253 return this.week;
254 }
255
256 /**
257 * Returns the first millisecond of the week. This will be determined
258 * relative to the time zone specified in the constructor, or in the
259 * calendar instance passed in the most recent call to the
260 * {@link #peg(Calendar)} method.
261 *
262 * @return The first millisecond of the week.
263 *
264 * @see #getLastMillisecond()
265 */
266 public long getFirstMillisecond() {
267 return this.firstMillisecond;
268 }
269
270 /**
271 * Returns the last millisecond of the week. This will be
272 * determined relative to the time zone specified in the constructor, or
273 * in the calendar instance passed in the most recent call to the
274 * {@link #peg(Calendar)} method.
275 *
276 * @return The last millisecond of the week.
277 *
278 * @see #getFirstMillisecond()
279 */
280 public long getLastMillisecond() {
281 return this.lastMillisecond;
282 }
283
284 /**
285 * Recalculates the start date/time and end date/time for this time period
286 * relative to the supplied calendar (which incorporates a time zone).
287 *
288 * @param calendar the calendar (<code>null</code> not permitted).
289 *
290 * @since 1.0.3
291 */
292 public void peg(Calendar calendar) {
293 this.firstMillisecond = getFirstMillisecond(calendar);
294 this.lastMillisecond = getLastMillisecond(calendar);
295 }
296
297 /**
298 * Returns the week preceding this one. This method will return
299 * <code>null</code> for some lower limit on the range of weeks (currently
300 * week 1, 1900). For week 1 of any year, the previous week is always week
301 * 53, but week 53 may not contain any days (you should check for this).
302 *
303 * @return The preceding week (possibly <code>null</code>).
304 */
305 public RegularTimePeriod previous() {
306
307 Week result;
308 if (this.week != FIRST_WEEK_IN_YEAR) {
309 result = new Week(this.week - 1, this.year);
310 }
311 else {
312 // we need to work out if the previous year has 52 or 53 weeks...
313 if (this.year > 1900) {
314 int yy = this.year - 1;
315 Calendar prevYearCalendar = Calendar.getInstance();
316 prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
317 result = new Week(prevYearCalendar.getActualMaximum(
318 Calendar.WEEK_OF_YEAR), yy);
319 }
320 else {
321 result = null;
322 }
323 }
324 return result;
325
326 }
327
328 /**
329 * Returns the week following this one. This method will return
330 * <code>null</code> for some upper limit on the range of weeks (currently
331 * week 53, 9999). For week 52 of any year, the following week is always
332 * week 53, but week 53 may not contain any days (you should check for
333 * this).
334 *
335 * @return The following week (possibly <code>null</code>).
336 */
337 public RegularTimePeriod next() {
338
339 Week result;
340 if (this.week < 52) {
341 result = new Week(this.week + 1, this.year);
342 }
343 else {
344 Calendar calendar = Calendar.getInstance();
345 calendar.set(this.year, Calendar.DECEMBER, 31);
346 int actualMaxWeek
347 = calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
348 if (this.week < actualMaxWeek) {
349 result = new Week(this.week + 1, this.year);
350 }
351 else {
352 if (this.year < 9999) {
353 result = new Week(FIRST_WEEK_IN_YEAR, this.year + 1);
354 }
355 else {
356 result = null;
357 }
358 }
359 }
360 return result;
361
362 }
363
364 /**
365 * Returns a serial index number for the week.
366 *
367 * @return The serial index number.
368 */
369 public long getSerialIndex() {
370 return this.year * 53L + this.week;
371 }
372
373 /**
374 * Returns the first millisecond of the week, evaluated using the supplied
375 * calendar (which determines the time zone).
376 *
377 * @param calendar the calendar (<code>null</code> not permitted).
378 *
379 * @return The first millisecond of the week.
380 *
381 * @throws NullPointerException if <code>calendar</code> is
382 * <code>null</code>.
383 */
384 public long getFirstMillisecond(Calendar calendar) {
385 Calendar c = (Calendar) calendar.clone();
386 c.clear();
387 c.set(Calendar.YEAR, this.year);
388 c.set(Calendar.WEEK_OF_YEAR, this.week);
389 c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
390 c.set(Calendar.HOUR, 0);
391 c.set(Calendar.MINUTE, 0);
392 c.set(Calendar.SECOND, 0);
393 c.set(Calendar.MILLISECOND, 0);
394 //return c.getTimeInMillis(); // this won't work for JDK 1.3
395 return c.getTime().getTime();
396 }
397
398 /**
399 * Returns the last millisecond of the week, evaluated using the supplied
400 * calendar (which determines the time zone).
401 *
402 * @param calendar the calendar (<code>null</code> not permitted).
403 *
404 * @return The last millisecond of the week.
405 *
406 * @throws NullPointerException if <code>calendar</code> is
407 * <code>null</code>.
408 */
409 public long getLastMillisecond(Calendar calendar) {
410 Calendar c = (Calendar) calendar.clone();
411 c.clear();
412 c.set(Calendar.YEAR, this.year);
413 c.set(Calendar.WEEK_OF_YEAR, this.week + 1);
414 c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
415 c.set(Calendar.HOUR, 0);
416 c.set(Calendar.MINUTE, 0);
417 c.set(Calendar.SECOND, 0);
418 c.set(Calendar.MILLISECOND, 0);
419 //return c.getTimeInMillis(); // this won't work for JDK 1.3
420 return c.getTime().getTime() - 1;
421 }
422
423 /**
424 * Returns a string representing the week (e.g. "Week 9, 2002").
425 *
426 * TODO: look at internationalisation.
427 *
428 * @return A string representing the week.
429 */
430 public String toString() {
431 return "Week " + this.week + ", " + this.year;
432 }
433
434 /**
435 * Tests the equality of this Week object to an arbitrary object. Returns
436 * true if the target is a Week instance representing the same week as this
437 * object. In all other cases, returns false.
438 *
439 * @param obj the object (<code>null</code> permitted).
440 *
441 * @return <code>true</code> if week and year of this and object are the
442 * same.
443 */
444 public boolean equals(Object obj) {
445
446 if (obj == this) {
447 return true;
448 }
449 if (!(obj instanceof Week)) {
450 return false;
451 }
452 Week that = (Week) obj;
453 if (this.week != that.week) {
454 return false;
455 }
456 if (this.year != that.year) {
457 return false;
458 }
459 return true;
460
461 }
462
463 /**
464 * Returns a hash code for this object instance. The approach described by
465 * Joshua Bloch in "Effective Java" has been used here:
466 * <p>
467 * <code>http://developer.java.sun.com/developer/Books/effectivejava
468 * /Chapter3.pdf</code>
469 *
470 * @return A hash code.
471 */
472 public int hashCode() {
473 int result = 17;
474 result = 37 * result + this.week;
475 result = 37 * result + this.year;
476 return result;
477 }
478
479 /**
480 * Returns an integer indicating the order of this Week object relative to
481 * the specified object:
482 *
483 * negative == before, zero == same, positive == after.
484 *
485 * @param o1 the object to compare.
486 *
487 * @return negative == before, zero == same, positive == after.
488 */
489 public int compareTo(Object o1) {
490
491 int result;
492
493 // CASE 1 : Comparing to another Week object
494 // --------------------------------------------
495 if (o1 instanceof Week) {
496 Week w = (Week) o1;
497 result = this.year - w.getYear().getYear();
498 if (result == 0) {
499 result = this.week - w.getWeek();
500 }
501 }
502
503 // CASE 2 : Comparing to another TimePeriod object
504 // -----------------------------------------------
505 else if (o1 instanceof RegularTimePeriod) {
506 // more difficult case - evaluate later...
507 result = 0;
508 }
509
510 // CASE 3 : Comparing to a non-TimePeriod object
511 // ---------------------------------------------
512 else {
513 // consider time periods to be ordered after general objects
514 result = 1;
515 }
516
517 return result;
518
519 }
520
521 /**
522 * Parses the string argument as a week.
523 * <P>
524 * This method is required to accept the format "YYYY-Wnn". It will also
525 * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
526 *
527 * @param s string to parse.
528 *
529 * @return <code>null</code> if the string is not parseable, the week
530 * otherwise.
531 */
532 public static Week parseWeek(String s) {
533
534 Week result = null;
535 if (s != null) {
536
537 // trim whitespace from either end of the string
538 s = s.trim();
539
540 int i = Week.findSeparator(s);
541 if (i != -1) {
542 String s1 = s.substring(0, i).trim();
543 String s2 = s.substring(i + 1, s.length()).trim();
544
545 Year y = Week.evaluateAsYear(s1);
546 int w;
547 if (y != null) {
548 w = Week.stringToWeek(s2);
549 if (w == -1) {
550 throw new TimePeriodFormatException(
551 "Can't evaluate the week.");
552 }
553 result = new Week(w, y);
554 }
555 else {
556 y = Week.evaluateAsYear(s2);
557 if (y != null) {
558 w = Week.stringToWeek(s1);
559 if (w == -1) {
560 throw new TimePeriodFormatException(
561 "Can't evaluate the week.");
562 }
563 result = new Week(w, y);
564 }
565 else {
566 throw new TimePeriodFormatException(
567 "Can't evaluate the year.");
568 }
569 }
570
571 }
572 else {
573 throw new TimePeriodFormatException(
574 "Could not find separator.");
575 }
576
577 }
578 return result;
579
580 }
581
582 /**
583 * Finds the first occurrence of ' ', '-', ',' or '.'
584 *
585 * @param s the string to parse.
586 *
587 * @return <code>-1</code> if none of the characters was found, the
588 * index of the first occurrence otherwise.
589 */
590 private static int findSeparator(String s) {
591
592 int result = s.indexOf('-');
593 if (result == -1) {
594 result = s.indexOf(',');
595 }
596 if (result == -1) {
597 result = s.indexOf(' ');
598 }
599 if (result == -1) {
600 result = s.indexOf('.');
601 }
602 return result;
603 }
604
605 /**
606 * Creates a year from a string, or returns null (format exceptions
607 * suppressed).
608 *
609 * @param s string to parse.
610 *
611 * @return <code>null</code> if the string is not parseable, the year
612 * otherwise.
613 */
614 private static Year evaluateAsYear(String s) {
615
616 Year result = null;
617 try {
618 result = Year.parseYear(s);
619 }
620 catch (TimePeriodFormatException e) {
621 // suppress
622 }
623 return result;
624
625 }
626
627 /**
628 * Converts a string to a week.
629 *
630 * @param s the string to parse.
631 * @return <code>-1</code> if the string does not contain a week number,
632 * the number of the week otherwise.
633 */
634 private static int stringToWeek(String s) {
635
636 int result = -1;
637 s = s.replace('W', ' ');
638 s = s.trim();
639 try {
640 result = Integer.parseInt(s);
641 if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
642 result = -1;
643 }
644 }
645 catch (NumberFormatException e) {
646 // suppress
647 }
648 return result;
649
650 }
651
652 }