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