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 * Month.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): Chris Boek;
034 *
035 * Changes
036 * -------
037 * 11-Oct-2001 : Version 1 (DG);
038 * 14-Nov-2001 : Added method to get year as primitive (DG);
039 * Override for toString() method (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 parseMonth() method (DG);
043 * 14-Feb-2002 : Fixed bugs in the Month constructors (DG);
044 * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to
045 * evaluate with reference to a particular time zone (DG);
046 * 19-Mar-2002 : Changed API for TimePeriod classes (DG);
047 * 10-Sep-2002 : Added getSerialIndex() method (DG);
048 * 04-Oct-2002 : Fixed errors reported by Checkstyle (DG);
049 * 10-Jan-2003 : Changed base class and method names (DG);
050 * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented
051 * Serializable (DG);
052 * 21-Oct-2003 : Added hashCode() method (DG);
053 * 01-Nov-2005 : Fixed bug 1345383 (argument check in constructor) (DG);
054 * ------------- JFREECHART 1.0.x ---------------------------------------------
055 * 05-Oct-2006 : Updated API docs (DG);
056 * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
057 * 04-Apr-2007 : Fixed bug in Month(Date, TimeZone) constructor (CB);
058 * 01-Sep-2008 : Added clarification for previous() and next() methods (DG);
059 * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE, and updated parsing to handle
060 * extended range in Year (DG);
061 * 25-Nov-2008 : Added new constructor with Locale (DG);
062 *
063 */
064
065 package org.jfree.data.time;
066
067 import java.io.Serializable;
068 import java.util.Calendar;
069 import java.util.Date;
070 import java.util.Locale;
071 import java.util.TimeZone;
072
073 import org.jfree.date.MonthConstants;
074 import org.jfree.date.SerialDate;
075
076 /**
077 * Represents a single month. This class is immutable, which is a requirement
078 * for all {@link RegularTimePeriod} subclasses.
079 */
080 public class Month extends RegularTimePeriod implements Serializable {
081
082 /** For serialization. */
083 private static final long serialVersionUID = -5090216912548722570L;
084
085 /** The month (1-12). */
086 private int month;
087
088 /** The year in which the month falls. */
089 private int year;
090
091 /** The first millisecond. */
092 private long firstMillisecond;
093
094 /** The last millisecond. */
095 private long lastMillisecond;
096
097 /**
098 * Constructs a new Month, based on the current system time.
099 */
100 public Month() {
101 this(new Date());
102 }
103
104 /**
105 * Constructs a new month instance.
106 *
107 * @param month the month (in the range 1 to 12).
108 * @param year the year.
109 */
110 public Month(int month, int year) {
111 if ((month < 1) || (month > 12)) {
112 throw new IllegalArgumentException("Month outside valid range.");
113 }
114 this.month = month;
115 this.year = year;
116 peg(Calendar.getInstance());
117 }
118
119 /**
120 * Constructs a new month instance.
121 *
122 * @param month the month (in the range 1 to 12).
123 * @param year the year.
124 */
125 public Month(int month, Year year) {
126 if ((month < 1) || (month > 12)) {
127 throw new IllegalArgumentException("Month outside valid range.");
128 }
129 this.month = month;
130 this.year = year.getYear();
131 peg(Calendar.getInstance());
132 }
133
134 /**
135 * Constructs a new <code>Month</code> instance, based on a date/time and
136 * the default time zone.
137 *
138 * @param time the date/time (<code>null</code> not permitted).
139 *
140 * @see #Month(Date, TimeZone)
141 */
142 public Month(Date time) {
143 this(time, TimeZone.getDefault());
144 }
145
146 /**
147 * Constructs a new <code>Month</code> instance, based on a date/time and
148 * a time zone. The first and last millisecond values are initially
149 * pegged to the given time zone also.
150 *
151 * @param time the date/time.
152 * @param zone the time zone (<code>null</code> not permitted).
153 *
154 * @deprecated Since 1.0.12, use {@link #Month(Date, TimeZone, Locale)}
155 * instead.
156 */
157 public Month(Date time, TimeZone zone) {
158 this(time, zone, Locale.getDefault());
159 }
160
161 /**
162 * Creates a new <code>Month</code> instance, based on the specified time,
163 * zone and locale.
164 *
165 * @param time the current time.
166 * @param zone the time zone.
167 * @param locale the locale.
168 *
169 * @since 1.0.12
170 */
171 public Month(Date time, TimeZone zone, Locale locale) {
172 Calendar calendar = Calendar.getInstance(zone);
173 calendar.setTime(time);
174 this.month = calendar.get(Calendar.MONTH) + 1;
175 this.year = calendar.get(Calendar.YEAR);
176 peg(calendar);
177 }
178
179 /**
180 * Returns the year in which the month falls.
181 *
182 * @return The year in which the month falls (as a Year object).
183 */
184 public Year getYear() {
185 return new Year(this.year);
186 }
187
188 /**
189 * Returns the year in which the month falls.
190 *
191 * @return The year in which the month falls (as an int).
192 */
193 public int getYearValue() {
194 return this.year;
195 }
196
197 /**
198 * Returns the month. Note that 1=JAN, 2=FEB, ...
199 *
200 * @return The month.
201 */
202 public int getMonth() {
203 return this.month;
204 }
205
206 /**
207 * Returns the first millisecond of the month. This will be determined
208 * relative to the time zone specified in the constructor, or in the
209 * calendar instance passed in the most recent call to the
210 * {@link #peg(Calendar)} method.
211 *
212 * @return The first millisecond of the month.
213 *
214 * @see #getLastMillisecond()
215 */
216 public long getFirstMillisecond() {
217 return this.firstMillisecond;
218 }
219
220 /**
221 * Returns the last millisecond of the month. This will be
222 * determined relative to the time zone specified in the constructor, or
223 * in the calendar instance passed in the most recent call to the
224 * {@link #peg(Calendar)} method.
225 *
226 * @return The last millisecond of the month.
227 *
228 * @see #getFirstMillisecond()
229 */
230 public long getLastMillisecond() {
231 return this.lastMillisecond;
232 }
233
234 /**
235 * Recalculates the start date/time and end date/time for this time period
236 * relative to the supplied calendar (which incorporates a time zone).
237 *
238 * @param calendar the calendar (<code>null</code> not permitted).
239 *
240 * @since 1.0.3
241 */
242 public void peg(Calendar calendar) {
243 this.firstMillisecond = getFirstMillisecond(calendar);
244 this.lastMillisecond = getLastMillisecond(calendar);
245 }
246
247 /**
248 * Returns the month preceding this one. Note that the returned
249 * {@link Month} is "pegged" using the default time-zone, irrespective of
250 * the time-zone used to peg of the current month (which is not recorded
251 * anywhere). See the {@link #peg(Calendar)} method.
252 *
253 * @return The month preceding this one.
254 */
255 public RegularTimePeriod previous() {
256 Month result;
257 if (this.month != MonthConstants.JANUARY) {
258 result = new Month(this.month - 1, this.year);
259 }
260 else {
261 if (this.year > 1900) {
262 result = new Month(MonthConstants.DECEMBER, this.year - 1);
263 }
264 else {
265 result = null;
266 }
267 }
268 return result;
269 }
270
271 /**
272 * Returns the month following this one. Note that the returned
273 * {@link Month} is "pegged" using the default time-zone, irrespective of
274 * the time-zone used to peg of the current month (which is not recorded
275 * anywhere). See the {@link #peg(Calendar)} method.
276 *
277 * @return The month following this one.
278 */
279 public RegularTimePeriod next() {
280 Month result;
281 if (this.month != MonthConstants.DECEMBER) {
282 result = new Month(this.month + 1, this.year);
283 }
284 else {
285 if (this.year < 9999) {
286 result = new Month(MonthConstants.JANUARY, this.year + 1);
287 }
288 else {
289 result = null;
290 }
291 }
292 return result;
293 }
294
295 /**
296 * Returns a serial index number for the month.
297 *
298 * @return The serial index number.
299 */
300 public long getSerialIndex() {
301 return this.year * 12L + this.month;
302 }
303
304 /**
305 * Returns a string representing the month (e.g. "January 2002").
306 * <P>
307 * To do: look at internationalisation.
308 *
309 * @return A string representing the month.
310 */
311 public String toString() {
312 return SerialDate.monthCodeToString(this.month) + " " + this.year;
313 }
314
315 /**
316 * Tests the equality of this Month object to an arbitrary object.
317 * Returns true if the target is a Month instance representing the same
318 * month as this object. In all other cases, returns false.
319 *
320 * @param obj the object (<code>null</code> permitted).
321 *
322 * @return <code>true</code> if month and year of this and object are the
323 * same.
324 */
325 public boolean equals(Object obj) {
326
327 if (obj != null) {
328 if (obj instanceof Month) {
329 Month target = (Month) obj;
330 return (this.month == target.getMonth()
331 && (this.year == target.getYearValue()));
332 }
333 else {
334 return false;
335 }
336 }
337 else {
338 return false;
339 }
340
341 }
342
343 /**
344 * Returns a hash code for this object instance. The approach described by
345 * Joshua Bloch in "Effective Java" has been used here:
346 * <p>
347 * <code>http://developer.java.sun.com/developer/Books/effectivejava
348 * /Chapter3.pdf</code>
349 *
350 * @return A hash code.
351 */
352 public int hashCode() {
353 int result = 17;
354 result = 37 * result + this.month;
355 result = 37 * result + this.year;
356 return result;
357 }
358
359 /**
360 * Returns an integer indicating the order of this Month object relative to
361 * the specified
362 * object: negative == before, zero == same, positive == after.
363 *
364 * @param o1 the object to compare.
365 *
366 * @return negative == before, zero == same, positive == after.
367 */
368 public int compareTo(Object o1) {
369
370 int result;
371
372 // CASE 1 : Comparing to another Month object
373 // --------------------------------------------
374 if (o1 instanceof Month) {
375 Month m = (Month) o1;
376 result = this.year - m.getYearValue();
377 if (result == 0) {
378 result = this.month - m.getMonth();
379 }
380 }
381
382 // CASE 2 : Comparing to another TimePeriod object
383 // -----------------------------------------------
384 else if (o1 instanceof RegularTimePeriod) {
385 // more difficult case - evaluate later...
386 result = 0;
387 }
388
389 // CASE 3 : Comparing to a non-TimePeriod object
390 // ---------------------------------------------
391 else {
392 // consider time periods to be ordered after general objects
393 result = 1;
394 }
395
396 return result;
397
398 }
399
400 /**
401 * Returns the first millisecond of the month, evaluated using the supplied
402 * calendar (which determines the time zone).
403 *
404 * @param calendar the calendar (<code>null</code> not permitted).
405 *
406 * @return The first millisecond of the month.
407 *
408 * @throws NullPointerException if <code>calendar</code> is
409 * <code>null</code>.
410 */
411 public long getFirstMillisecond(Calendar calendar) {
412 calendar.set(this.year, this.month - 1, 1, 0, 0, 0);
413 calendar.set(Calendar.MILLISECOND, 0);
414 // in the following line, we'd rather call calendar.getTimeInMillis()
415 // to avoid object creation, but that isn't supported in Java 1.3.1
416 return calendar.getTime().getTime();
417 }
418
419 /**
420 * Returns the last millisecond of the month, evaluated using the supplied
421 * calendar (which determines the time zone).
422 *
423 * @param calendar the calendar (<code>null</code> not permitted).
424 *
425 * @return The last millisecond of the month.
426 *
427 * @throws NullPointerException if <code>calendar</code> is
428 * <code>null</code>.
429 */
430 public long getLastMillisecond(Calendar calendar) {
431 int eom = SerialDate.lastDayOfMonth(this.month, this.year);
432 calendar.set(this.year, this.month - 1, eom, 23, 59, 59);
433 calendar.set(Calendar.MILLISECOND, 999);
434 // in the following line, we'd rather call calendar.getTimeInMillis()
435 // to avoid object creation, but that isn't supported in Java 1.3.1
436 return calendar.getTime().getTime();
437 }
438
439 /**
440 * Parses the string argument as a month. This method is required to
441 * accept the format "YYYY-MM". It will also accept "MM-YYYY". Anything
442 * else, at the moment, is a bonus.
443 *
444 * @param s the string to parse (<code>null</code> permitted).
445 *
446 * @return <code>null</code> if the string is not parseable, the month
447 * otherwise.
448 */
449 public static Month parseMonth(String s) {
450 Month result = null;
451 if (s == null) {
452 return result;
453 }
454 // trim whitespace from either end of the string
455 s = s.trim();
456 int i = Month.findSeparator(s);
457 String s1, s2;
458 boolean yearIsFirst;
459 // if there is no separator, we assume the first four characters
460 // are YYYY
461 if (i == -1) {
462 yearIsFirst = true;
463 s1 = s.substring(0, 5);
464 s2 = s.substring(5);
465 }
466 else {
467 s1 = s.substring(0, i).trim();
468 s2 = s.substring(i + 1, s.length()).trim();
469 // now it is trickier to determine if the month or year is first
470 Year y1 = Month.evaluateAsYear(s1);
471 if (y1 == null) {
472 yearIsFirst = false;
473 }
474 else {
475 Year y2 = Month.evaluateAsYear(s2);
476 if (y2 == null) {
477 yearIsFirst = true;
478 }
479 else {
480 yearIsFirst = (s1.length() > s2.length());
481 }
482 }
483 }
484 Year year;
485 int month;
486 if (yearIsFirst) {
487 year = Month.evaluateAsYear(s1);
488 month = SerialDate.stringToMonthCode(s2);
489 }
490 else {
491 year = Month.evaluateAsYear(s2);
492 month = SerialDate.stringToMonthCode(s1);
493 }
494 if (month == -1) {
495 throw new TimePeriodFormatException("Can't evaluate the month.");
496 }
497 if (year == null) {
498 throw new TimePeriodFormatException("Can't evaluate the year.");
499 }
500 result = new Month(month, year);
501 return result;
502 }
503
504 /**
505 * Finds the first occurrence of '-', or if that character is not found,
506 * the first occurrence of ',', or the first occurrence of ' ' or '.'
507 *
508 * @param s the string to parse.
509 *
510 * @return The position of the separator character, or <code>-1</code> if
511 * none of the characters were found.
512 */
513 private static int findSeparator(String s) {
514 int result = s.indexOf('-');
515 if (result == -1) {
516 result = s.indexOf(',');
517 }
518 if (result == -1) {
519 result = s.indexOf(' ');
520 }
521 if (result == -1) {
522 result = s.indexOf('.');
523 }
524 return result;
525 }
526
527 /**
528 * Creates a year from a string, or returns <code>null</code> (format
529 * exceptions suppressed).
530 *
531 * @param s the string to parse.
532 *
533 * @return <code>null</code> if the string is not parseable, the year
534 * otherwise.
535 */
536 private static Year evaluateAsYear(String s) {
537 Year result = null;
538 try {
539 result = Year.parseYear(s);
540 }
541 catch (TimePeriodFormatException e) {
542 // suppress
543 }
544 return result;
545 }
546
547 }