001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2009, 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 2001-2009, 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 * 04-Feb-2009 : Fix for new constructor with Locale - bug 2564636 (DG);
063 *
064 */
065
066 package org.jfree.data.time;
067
068 import java.io.Serializable;
069 import java.util.Calendar;
070 import java.util.Date;
071 import java.util.Locale;
072 import java.util.TimeZone;
073
074 import org.jfree.date.MonthConstants;
075 import org.jfree.date.SerialDate;
076
077 /**
078 * Represents a single month. This class is immutable, which is a requirement
079 * for all {@link RegularTimePeriod} subclasses.
080 */
081 public class Month extends RegularTimePeriod implements Serializable {
082
083 /** For serialization. */
084 private static final long serialVersionUID = -5090216912548722570L;
085
086 /** The month (1-12). */
087 private int month;
088
089 /** The year in which the month falls. */
090 private int year;
091
092 /** The first millisecond. */
093 private long firstMillisecond;
094
095 /** The last millisecond. */
096 private long lastMillisecond;
097
098 /**
099 * Constructs a new Month, based on the current system time.
100 */
101 public Month() {
102 this(new Date());
103 }
104
105 /**
106 * Constructs a new month instance.
107 *
108 * @param month the month (in the range 1 to 12).
109 * @param year the year.
110 */
111 public Month(int month, int year) {
112 if ((month < 1) || (month > 12)) {
113 throw new IllegalArgumentException("Month outside valid range.");
114 }
115 this.month = month;
116 this.year = year;
117 peg(Calendar.getInstance());
118 }
119
120 /**
121 * Constructs a new month instance.
122 *
123 * @param month the month (in the range 1 to 12).
124 * @param year the year.
125 */
126 public Month(int month, Year year) {
127 if ((month < 1) || (month > 12)) {
128 throw new IllegalArgumentException("Month outside valid range.");
129 }
130 this.month = month;
131 this.year = year.getYear();
132 peg(Calendar.getInstance());
133 }
134
135 /**
136 * Constructs a new <code>Month</code> instance, based on a date/time and
137 * the default time zone.
138 *
139 * @param time the date/time (<code>null</code> not permitted).
140 *
141 * @see #Month(Date, TimeZone)
142 */
143 public Month(Date time) {
144 this(time, TimeZone.getDefault());
145 }
146
147 /**
148 * Constructs a new <code>Month</code> instance, based on a date/time and
149 * a time zone. The first and last millisecond values are initially
150 * pegged to the given time zone also.
151 *
152 * @param time the date/time.
153 * @param zone the time zone (<code>null</code> not permitted).
154 *
155 * @deprecated Since 1.0.12, use {@link #Month(Date, TimeZone, Locale)}
156 * instead.
157 */
158 public Month(Date time, TimeZone zone) {
159 this(time, zone, Locale.getDefault());
160 }
161
162 /**
163 * Creates a new <code>Month</code> instance, based on the specified time,
164 * zone and locale.
165 *
166 * @param time the current time.
167 * @param zone the time zone.
168 * @param locale the locale.
169 *
170 * @since 1.0.12
171 */
172 public Month(Date time, TimeZone zone, Locale locale) {
173 Calendar calendar = Calendar.getInstance(zone, locale);
174 calendar.setTime(time);
175 this.month = calendar.get(Calendar.MONTH) + 1;
176 this.year = calendar.get(Calendar.YEAR);
177 peg(calendar);
178 }
179
180 /**
181 * Returns the year in which the month falls.
182 *
183 * @return The year in which the month falls (as a Year object).
184 */
185 public Year getYear() {
186 return new Year(this.year);
187 }
188
189 /**
190 * Returns the year in which the month falls.
191 *
192 * @return The year in which the month falls (as an int).
193 */
194 public int getYearValue() {
195 return this.year;
196 }
197
198 /**
199 * Returns the month. Note that 1=JAN, 2=FEB, ...
200 *
201 * @return The month.
202 */
203 public int getMonth() {
204 return this.month;
205 }
206
207 /**
208 * Returns the first millisecond of the month. This will be determined
209 * relative to the time zone specified in the constructor, or in the
210 * calendar instance passed in the most recent call to the
211 * {@link #peg(Calendar)} method.
212 *
213 * @return The first millisecond of the month.
214 *
215 * @see #getLastMillisecond()
216 */
217 public long getFirstMillisecond() {
218 return this.firstMillisecond;
219 }
220
221 /**
222 * Returns the last millisecond of the month. This will be
223 * determined relative to the time zone specified in the constructor, or
224 * in the calendar instance passed in the most recent call to the
225 * {@link #peg(Calendar)} method.
226 *
227 * @return The last millisecond of the month.
228 *
229 * @see #getFirstMillisecond()
230 */
231 public long getLastMillisecond() {
232 return this.lastMillisecond;
233 }
234
235 /**
236 * Recalculates the start date/time and end date/time for this time period
237 * relative to the supplied calendar (which incorporates a time zone).
238 *
239 * @param calendar the calendar (<code>null</code> not permitted).
240 *
241 * @since 1.0.3
242 */
243 public void peg(Calendar calendar) {
244 this.firstMillisecond = getFirstMillisecond(calendar);
245 this.lastMillisecond = getLastMillisecond(calendar);
246 }
247
248 /**
249 * Returns the month preceding this one. Note that the returned
250 * {@link Month} is "pegged" using the default time-zone, irrespective of
251 * the time-zone used to peg of the current month (which is not recorded
252 * anywhere). See the {@link #peg(Calendar)} method.
253 *
254 * @return The month preceding this one.
255 */
256 public RegularTimePeriod previous() {
257 Month result;
258 if (this.month != MonthConstants.JANUARY) {
259 result = new Month(this.month - 1, this.year);
260 }
261 else {
262 if (this.year > 1900) {
263 result = new Month(MonthConstants.DECEMBER, this.year - 1);
264 }
265 else {
266 result = null;
267 }
268 }
269 return result;
270 }
271
272 /**
273 * Returns the month following this one. Note that the returned
274 * {@link Month} is "pegged" using the default time-zone, irrespective of
275 * the time-zone used to peg of the current month (which is not recorded
276 * anywhere). See the {@link #peg(Calendar)} method.
277 *
278 * @return The month following this one.
279 */
280 public RegularTimePeriod next() {
281 Month result;
282 if (this.month != MonthConstants.DECEMBER) {
283 result = new Month(this.month + 1, this.year);
284 }
285 else {
286 if (this.year < 9999) {
287 result = new Month(MonthConstants.JANUARY, this.year + 1);
288 }
289 else {
290 result = null;
291 }
292 }
293 return result;
294 }
295
296 /**
297 * Returns a serial index number for the month.
298 *
299 * @return The serial index number.
300 */
301 public long getSerialIndex() {
302 return this.year * 12L + this.month;
303 }
304
305 /**
306 * Returns a string representing the month (e.g. "January 2002").
307 * <P>
308 * To do: look at internationalisation.
309 *
310 * @return A string representing the month.
311 */
312 public String toString() {
313 return SerialDate.monthCodeToString(this.month) + " " + this.year;
314 }
315
316 /**
317 * Tests the equality of this Month object to an arbitrary object.
318 * Returns true if the target is a Month instance representing the same
319 * month as this object. In all other cases, returns false.
320 *
321 * @param obj the object (<code>null</code> permitted).
322 *
323 * @return <code>true</code> if month and year of this and object are the
324 * same.
325 */
326 public boolean equals(Object obj) {
327 if (obj == this) {
328 return true;
329 }
330 if (!(obj instanceof Month)) {
331 return false;
332 }
333 Month that = (Month) obj;
334 if (this.month != that.month) {
335 return false;
336 }
337 if (this.year != that.year) {
338 return false;
339 }
340 return true;
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 }