001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 2001-2007, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): Aimin Han;
034 *
035 * $Id: Week.java,v 1.7.2.5 2007/01/10 11:43:46 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 11-Oct-2001 : Version 1 (DG);
040 * 18-Dec-2001 : Changed order of parameters in constructor (DG);
041 * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
042 * 29-Jan-2002 : Worked on the parseWeek() method (DG);
043 * 13-Feb-2002 : Fixed bug in Week(Date) constructor (DG);
044 * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to
045 * evaluate with reference to a particular time zone (DG);
046 * 05-Apr-2002 : Reinstated this class to the JCommon library (DG);
047 * 24-Jun-2002 : Removed unnecessary main method (DG);
048 * 10-Sep-2002 : Added getSerialIndex() method (DG);
049 * 06-Oct-2002 : Fixed errors reported by Checkstyle (DG);
050 * 18-Oct-2002 : Changed to observe 52 or 53 weeks per year, consistent with
051 * GregorianCalendar. Thanks to Aimin Han for the code (DG);
052 * 02-Jan-2003 : Removed debug code (DG);
053 * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented
054 * Serializable (DG);
055 * 21-Oct-2003 : Added hashCode() method (DG);
056 * 24-May-2004 : Modified getFirstMillisecond() and getLastMillisecond() to
057 * take account of firstDayOfWeek setting in Java's Calendar
058 * class (DG);
059 * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
060 * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for
061 * JDK 1.3 (DG);
062 * ------------- JFREECHART 1.0.x ---------------------------------------------
063 * 06-Mar-2006 : Fix for bug 1448828, incorrect calculation of week and year
064 * for the first few days of some years (DG);
065 * 05-Oct-2006 : Updated API docs (DG);
066 * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
067 * 09-Jan-2007 : Fixed bug in next() (DG);
068 *
069 */
070
071 package org.jfree.data.time;
072
073 import java.io.Serializable;
074 import java.util.Calendar;
075 import java.util.Date;
076 import java.util.TimeZone;
077
078 /**
079 * A calendar week. All years are considered to have 53 weeks, numbered from 1
080 * to 53, although in many cases the 53rd week is empty. Most of the time, the
081 * 1st week of the year *begins* in the previous calendar year, but it always
082 * finishes in the current year (this behaviour matches the workings of the
083 * <code>GregorianCalendar</code> class).
084 * <P>
085 * This class is immutable, which is a requirement for all
086 * {@link RegularTimePeriod} subclasses.
087 */
088 public class Week extends RegularTimePeriod implements Serializable {
089
090 /** For serialization. */
091 private static final long serialVersionUID = 1856387786939865061L;
092
093 /** Constant for the first week in the year. */
094 public static final int FIRST_WEEK_IN_YEAR = 1;
095
096 /** Constant for the last week in the year. */
097 public static final int LAST_WEEK_IN_YEAR = 53;
098
099 /** The year in which the week falls. */
100 private short year;
101
102 /** The week (1-53). */
103 private byte week;
104
105 /** The first millisecond. */
106 private long firstMillisecond;
107
108 /** The last millisecond. */
109 private long lastMillisecond;
110
111 /**
112 * Creates a new time period for the week in which the current system
113 * date/time falls.
114 */
115 public Week() {
116 this(new Date());
117 }
118
119 /**
120 * Creates a time period representing the week in the specified year.
121 *
122 * @param week the week (1 to 53).
123 * @param year the year (1900 to 9999).
124 */
125 public Week(int week, int year) {
126 if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
127 throw new IllegalArgumentException(
128 "The 'week' argument must be in the range 1 - 53.");
129 }
130 this.week = (byte) week;
131 this.year = (short) year;
132 peg(Calendar.getInstance());
133 }
134
135 /**
136 * Creates a time period representing the week in the specified year.
137 *
138 * @param week the week (1 to 53).
139 * @param year the year (1900 to 9999).
140 */
141 public Week(int week, Year year) {
142 if ((week < FIRST_WEEK_IN_YEAR) && (week > LAST_WEEK_IN_YEAR)) {
143 throw new IllegalArgumentException(
144 "The 'week' argument must be in the range 1 - 53.");
145 }
146 this.week = (byte) week;
147 this.year = (short) year.getYear();
148 peg(Calendar.getInstance());
149 }
150
151 /**
152 * Creates a time period for the week in which the specified date/time
153 * falls.
154 *
155 * @param time the time (<code>null</code> not permitted).
156 */
157 public Week(Date time) {
158 // defer argument checking...
159 this(time, RegularTimePeriod.DEFAULT_TIME_ZONE);
160 }
161
162 /**
163 * Creates a time period for the week in which the specified date/time
164 * falls, calculated relative to the specified time zone.
165 *
166 * @param time the date/time (<code>null</code> not permitted).
167 * @param zone the time zone (<code>null</code> not permitted).
168 */
169 public Week(Date time, TimeZone zone) {
170 if (time == null) {
171 throw new IllegalArgumentException("Null 'time' argument.");
172 }
173 if (zone == null) {
174 throw new IllegalArgumentException("Null 'zone' argument.");
175 }
176 Calendar calendar = Calendar.getInstance(zone);
177 calendar.setTime(time);
178
179 // sometimes the last few days of the year are considered to fall in
180 // the *first* week of the following year. Refer to the Javadocs for
181 // GregorianCalendar.
182 int tempWeek = calendar.get(Calendar.WEEK_OF_YEAR);
183 if (tempWeek == 1
184 && calendar.get(Calendar.MONTH) == Calendar.DECEMBER) {
185 this.week = 1;
186 this.year = (short) (calendar.get(Calendar.YEAR) + 1);
187 }
188 else {
189 this.week = (byte) Math.min(tempWeek, LAST_WEEK_IN_YEAR);
190 int yyyy = calendar.get(Calendar.YEAR);
191 // alternatively, sometimes the first few days of the year are
192 // considered to fall in the *last* week of the previous year...
193 if (calendar.get(Calendar.MONTH) == Calendar.JANUARY
194 && this.week >= 52) {
195 yyyy--;
196 }
197 this.year = (short) yyyy;
198 }
199 peg(calendar);
200
201 }
202
203 /**
204 * Returns the year in which the week falls.
205 *
206 * @return The year (never <code>null</code>).
207 */
208 public Year getYear() {
209 return new Year(this.year);
210 }
211
212 /**
213 * Returns the year in which the week falls, as an integer value.
214 *
215 * @return The year.
216 */
217 public int getYearValue() {
218 return this.year;
219 }
220
221 /**
222 * Returns the week.
223 *
224 * @return The week.
225 */
226 public int getWeek() {
227 return this.week;
228 }
229
230 /**
231 * Returns the first millisecond of the week. This will be determined
232 * relative to the time zone specified in the constructor, or in the
233 * calendar instance passed in the most recent call to the
234 * {@link #peg(Calendar)} method.
235 *
236 * @return The first millisecond of the week.
237 *
238 * @see #getLastMillisecond()
239 */
240 public long getFirstMillisecond() {
241 return this.firstMillisecond;
242 }
243
244 /**
245 * Returns the last millisecond of the week. This will be
246 * determined relative to the time zone specified in the constructor, or
247 * in the calendar instance passed in the most recent call to the
248 * {@link #peg(Calendar)} method.
249 *
250 * @return The last millisecond of the week.
251 *
252 * @see #getFirstMillisecond()
253 */
254 public long getLastMillisecond() {
255 return this.lastMillisecond;
256 }
257
258 /**
259 * Recalculates the start date/time and end date/time for this time period
260 * relative to the supplied calendar (which incorporates a time zone).
261 *
262 * @param calendar the calendar (<code>null</code> not permitted).
263 *
264 * @since 1.0.3
265 */
266 public void peg(Calendar calendar) {
267 this.firstMillisecond = getFirstMillisecond(calendar);
268 this.lastMillisecond = getLastMillisecond(calendar);
269 }
270
271 /**
272 * Returns the week preceding this one. This method will return
273 * <code>null</code> for some lower limit on the range of weeks (currently
274 * week 1, 1900). For week 1 of any year, the previous week is always week
275 * 53, but week 53 may not contain any days (you should check for this).
276 *
277 * @return The preceding week (possibly <code>null</code>).
278 */
279 public RegularTimePeriod previous() {
280
281 Week result;
282 if (this.week != FIRST_WEEK_IN_YEAR) {
283 result = new Week(this.week - 1, this.year);
284 }
285 else {
286 // we need to work out if the previous year has 52 or 53 weeks...
287 if (this.year > 1900) {
288 int yy = this.year - 1;
289 Calendar prevYearCalendar = Calendar.getInstance();
290 prevYearCalendar.set(yy, Calendar.DECEMBER, 31);
291 result = new Week(prevYearCalendar.getActualMaximum(
292 Calendar.WEEK_OF_YEAR), yy);
293 }
294 else {
295 result = null;
296 }
297 }
298 return result;
299
300 }
301
302 /**
303 * Returns the week following this one. This method will return
304 * <code>null</code> for some upper limit on the range of weeks (currently
305 * week 53, 9999). For week 52 of any year, the following week is always
306 * week 53, but week 53 may not contain any days (you should check for
307 * this).
308 *
309 * @return The following week (possibly <code>null</code>).
310 */
311 public RegularTimePeriod next() {
312
313 Week result;
314 if (this.week < 52) {
315 result = new Week(this.week + 1, this.year);
316 }
317 else {
318 Calendar calendar = Calendar.getInstance();
319 calendar.set(this.year, Calendar.DECEMBER, 31);
320 int actualMaxWeek
321 = calendar.getActualMaximum(Calendar.WEEK_OF_YEAR);
322 if (this.week < actualMaxWeek) {
323 result = new Week(this.week + 1, this.year);
324 }
325 else {
326 if (this.year < 9999) {
327 result = new Week(FIRST_WEEK_IN_YEAR, this.year + 1);
328 }
329 else {
330 result = null;
331 }
332 }
333 }
334 return result;
335
336 }
337
338 /**
339 * Returns a serial index number for the week.
340 *
341 * @return The serial index number.
342 */
343 public long getSerialIndex() {
344 return this.year * 53L + this.week;
345 }
346
347 /**
348 * Returns the first millisecond of the week, evaluated using the supplied
349 * calendar (which determines the time zone).
350 *
351 * @param calendar the calendar (<code>null</code> not permitted).
352 *
353 * @return The first millisecond of the week.
354 *
355 * @throws NullPointerException if <code>calendar</code> is
356 * <code>null</code>.
357 */
358 public long getFirstMillisecond(Calendar calendar) {
359 Calendar c = (Calendar) calendar.clone();
360 c.clear();
361 c.set(Calendar.YEAR, this.year);
362 c.set(Calendar.WEEK_OF_YEAR, this.week);
363 c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
364 c.set(Calendar.HOUR, 0);
365 c.set(Calendar.MINUTE, 0);
366 c.set(Calendar.SECOND, 0);
367 c.set(Calendar.MILLISECOND, 0);
368 //return c.getTimeInMillis(); // this won't work for JDK 1.3
369 return c.getTime().getTime();
370 }
371
372 /**
373 * Returns the last millisecond of the week, evaluated using the supplied
374 * calendar (which determines the time zone).
375 *
376 * @param calendar the calendar (<code>null</code> not permitted).
377 *
378 * @return The last millisecond of the week.
379 *
380 * @throws NullPointerException if <code>calendar</code> is
381 * <code>null</code>.
382 */
383 public long getLastMillisecond(Calendar calendar) {
384 Calendar c = (Calendar) calendar.clone();
385 c.clear();
386 c.set(Calendar.YEAR, this.year);
387 c.set(Calendar.WEEK_OF_YEAR, this.week + 1);
388 c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
389 c.set(Calendar.HOUR, 0);
390 c.set(Calendar.MINUTE, 0);
391 c.set(Calendar.SECOND, 0);
392 c.set(Calendar.MILLISECOND, 0);
393 //return c.getTimeInMillis(); // this won't work for JDK 1.3
394 return c.getTime().getTime() - 1;
395 }
396
397 /**
398 * Returns a string representing the week (e.g. "Week 9, 2002").
399 *
400 * TODO: look at internationalisation.
401 *
402 * @return A string representing the week.
403 */
404 public String toString() {
405 return "Week " + this.week + ", " + this.year;
406 }
407
408 /**
409 * Tests the equality of this Week object to an arbitrary object. Returns
410 * true if the target is a Week instance representing the same week as this
411 * object. In all other cases, returns false.
412 *
413 * @param obj the object (<code>null</code> permitted).
414 *
415 * @return <code>true</code> if week and year of this and object are the
416 * same.
417 */
418 public boolean equals(Object obj) {
419
420 if (obj == this) {
421 return true;
422 }
423 if (!(obj instanceof Week)) {
424 return false;
425 }
426 Week that = (Week) obj;
427 if (this.week != that.week) {
428 return false;
429 }
430 if (this.year != that.year) {
431 return false;
432 }
433 return true;
434
435 }
436
437 /**
438 * Returns a hash code for this object instance. The approach described by
439 * Joshua Bloch in "Effective Java" has been used here:
440 * <p>
441 * <code>http://developer.java.sun.com/developer/Books/effectivejava
442 * /Chapter3.pdf</code>
443 *
444 * @return A hash code.
445 */
446 public int hashCode() {
447 int result = 17;
448 result = 37 * result + this.week;
449 result = 37 * result + this.year;
450 return result;
451 }
452
453 /**
454 * Returns an integer indicating the order of this Week object relative to
455 * the specified object:
456 *
457 * negative == before, zero == same, positive == after.
458 *
459 * @param o1 the object to compare.
460 *
461 * @return negative == before, zero == same, positive == after.
462 */
463 public int compareTo(Object o1) {
464
465 int result;
466
467 // CASE 1 : Comparing to another Week object
468 // --------------------------------------------
469 if (o1 instanceof Week) {
470 Week w = (Week) o1;
471 result = this.year - w.getYear().getYear();
472 if (result == 0) {
473 result = this.week - w.getWeek();
474 }
475 }
476
477 // CASE 2 : Comparing to another TimePeriod object
478 // -----------------------------------------------
479 else if (o1 instanceof RegularTimePeriod) {
480 // more difficult case - evaluate later...
481 result = 0;
482 }
483
484 // CASE 3 : Comparing to a non-TimePeriod object
485 // ---------------------------------------------
486 else {
487 // consider time periods to be ordered after general objects
488 result = 1;
489 }
490
491 return result;
492
493 }
494
495 /**
496 * Parses the string argument as a week.
497 * <P>
498 * This method is required to accept the format "YYYY-Wnn". It will also
499 * accept "Wnn-YYYY". Anything else, at the moment, is a bonus.
500 *
501 * @param s string to parse.
502 *
503 * @return <code>null</code> if the string is not parseable, the week
504 * otherwise.
505 */
506 public static Week parseWeek(String s) {
507
508 Week result = null;
509 if (s != null) {
510
511 // trim whitespace from either end of the string
512 s = s.trim();
513
514 int i = Week.findSeparator(s);
515 if (i != -1) {
516 String s1 = s.substring(0, i).trim();
517 String s2 = s.substring(i + 1, s.length()).trim();
518
519 Year y = Week.evaluateAsYear(s1);
520 int w;
521 if (y != null) {
522 w = Week.stringToWeek(s2);
523 if (w == -1) {
524 throw new TimePeriodFormatException(
525 "Can't evaluate the week."
526 );
527 }
528 result = new Week(w, y);
529 }
530 else {
531 y = Week.evaluateAsYear(s2);
532 if (y != null) {
533 w = Week.stringToWeek(s1);
534 if (w == -1) {
535 throw new TimePeriodFormatException(
536 "Can't evaluate the week."
537 );
538 }
539 result = new Week(w, y);
540 }
541 else {
542 throw new TimePeriodFormatException(
543 "Can't evaluate the year."
544 );
545 }
546 }
547
548 }
549 else {
550 throw new TimePeriodFormatException(
551 "Could not find separator."
552 );
553 }
554
555 }
556 return result;
557
558 }
559
560 /**
561 * Finds the first occurrence of ' ', '-', ',' or '.'
562 *
563 * @param s the string to parse.
564 *
565 * @return <code>-1</code> if none of the characters was found, the
566 * index of the first occurrence otherwise.
567 */
568 private static int findSeparator(String s) {
569
570 int result = s.indexOf('-');
571 if (result == -1) {
572 result = s.indexOf(',');
573 }
574 if (result == -1) {
575 result = s.indexOf(' ');
576 }
577 if (result == -1) {
578 result = s.indexOf('.');
579 }
580 return result;
581 }
582
583 /**
584 * Creates a year from a string, or returns null (format exceptions
585 * suppressed).
586 *
587 * @param s string to parse.
588 *
589 * @return <code>null</code> if the string is not parseable, the year
590 * otherwise.
591 */
592 private static Year evaluateAsYear(String s) {
593
594 Year result = null;
595 try {
596 result = Year.parseYear(s);
597 }
598 catch (TimePeriodFormatException e) {
599 // suppress
600 }
601 return result;
602
603 }
604
605 /**
606 * Converts a string to a week.
607 *
608 * @param s the string to parse.
609 * @return <code>-1</code> if the string does not contain a week number,
610 * the number of the week otherwise.
611 */
612 private static int stringToWeek(String s) {
613
614 int result = -1;
615 s = s.replace('W', ' ');
616 s = s.trim();
617 try {
618 result = Integer.parseInt(s);
619 if ((result < 1) || (result > LAST_WEEK_IN_YEAR)) {
620 result = -1;
621 }
622 }
623 catch (NumberFormatException e) {
624 // suppress
625 }
626 return result;
627
628 }
629
630 }