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 * Year.java
029 * ---------
030 * (C) Copyright 2001-2007, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 11-Oct-2001 : Version 1 (DG);
038 * 14-Nov-2001 : Override for toString() method (DG);
039 * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
040 * 29-Jan-2002 : Worked on parseYear() method (DG);
041 * 14-Feb-2002 : Fixed bug in Year(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 * 19-Mar-2002 : Changed API for TimePeriod classes (DG);
045 * 10-Sep-2002 : Added getSerialIndex() method (DG);
046 * 04-Oct-2002 : Fixed errors reported by Checkstyle (DG);
047 * 10-Jan-2003 : Changed base class and method names (DG);
048 * 05-Mar-2003 : Fixed bug in getFirstMillisecond() picked up in JUnit
049 * tests (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 * ------------- JFREECHART 1.0.x ---------------------------------------------
054 * 05-Oct-2006 : Updated API docs (DG);
055 * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
056 *
057 */
058
059 package org.jfree.data.time;
060
061 import java.io.Serializable;
062 import java.util.Calendar;
063 import java.util.Date;
064 import java.util.TimeZone;
065
066 import org.jfree.date.SerialDate;
067
068 /**
069 * Represents a year in the range 1900 to 9999. This class is immutable, which
070 * is a requirement for all {@link RegularTimePeriod} subclasses.
071 */
072 public class Year extends RegularTimePeriod implements Serializable {
073
074 /** For serialization. */
075 private static final long serialVersionUID = -7659990929736074836L;
076
077 /** The year. */
078 private short year;
079
080 /** The first millisecond. */
081 private long firstMillisecond;
082
083 /** The last millisecond. */
084 private long lastMillisecond;
085
086 /**
087 * Creates a new <code>Year</code>, based on the current system date/time.
088 */
089 public Year() {
090 this(new Date());
091 }
092
093 /**
094 * Creates a time period representing a single year.
095 *
096 * @param year the year.
097 */
098 public Year(int year) {
099 if ((year < SerialDate.MINIMUM_YEAR_SUPPORTED)
100 || (year > SerialDate.MAXIMUM_YEAR_SUPPORTED)) {
101
102 throw new IllegalArgumentException(
103 "Year constructor: year (" + year + ") outside valid range.");
104 }
105 this.year = (short) year;
106 peg(Calendar.getInstance());
107 }
108
109 /**
110 * Creates a new <code>Year</code>, based on a particular instant in time,
111 * using the default time zone.
112 *
113 * @param time the time (<code>null</code> not permitted).
114 */
115 public Year(Date time) {
116 this(time, RegularTimePeriod.DEFAULT_TIME_ZONE);
117 }
118
119 /**
120 * Constructs a year, based on a particular instant in time and a time zone.
121 *
122 * @param time the time.
123 * @param zone the time zone.
124 */
125 public Year(Date time, TimeZone zone) {
126 Calendar calendar = Calendar.getInstance(zone);
127 calendar.setTime(time);
128 this.year = (short) calendar.get(Calendar.YEAR);
129 peg(calendar);
130 }
131
132 /**
133 * Returns the year.
134 *
135 * @return The year.
136 */
137 public int getYear() {
138 return this.year;
139 }
140
141 /**
142 * Returns the first millisecond of the year. This will be determined
143 * relative to the time zone specified in the constructor, or in the
144 * calendar instance passed in the most recent call to the
145 * {@link #peg(Calendar)} method.
146 *
147 * @return The first millisecond of the year.
148 *
149 * @see #getLastMillisecond()
150 */
151 public long getFirstMillisecond() {
152 return this.firstMillisecond;
153 }
154
155 /**
156 * Returns the last millisecond of the year. This will be
157 * determined relative to the time zone specified in the constructor, or
158 * in the calendar instance passed in the most recent call to the
159 * {@link #peg(Calendar)} method.
160 *
161 * @return The last millisecond of the year.
162 *
163 * @see #getFirstMillisecond()
164 */
165 public long getLastMillisecond() {
166 return this.lastMillisecond;
167 }
168
169 /**
170 * Recalculates the start date/time and end date/time for this time period
171 * relative to the supplied calendar (which incorporates a time zone).
172 *
173 * @param calendar the calendar (<code>null</code> not permitted).
174 *
175 * @since 1.0.3
176 */
177 public void peg(Calendar calendar) {
178 this.firstMillisecond = getFirstMillisecond(calendar);
179 this.lastMillisecond = getLastMillisecond(calendar);
180 }
181
182 /**
183 * Returns the year preceding this one.
184 *
185 * @return The year preceding this one (or <code>null</code> if the
186 * current year is 1900).
187 */
188 public RegularTimePeriod previous() {
189 if (this.year > SerialDate.MINIMUM_YEAR_SUPPORTED) {
190 return new Year(this.year - 1);
191 }
192 else {
193 return null;
194 }
195 }
196
197 /**
198 * Returns the year following this one.
199 *
200 * @return The year following this one (or <code>null</code> if the current
201 * year is 9999).
202 */
203 public RegularTimePeriod next() {
204 if (this.year < SerialDate.MAXIMUM_YEAR_SUPPORTED) {
205 return new Year(this.year + 1);
206 }
207 else {
208 return null;
209 }
210 }
211
212 /**
213 * Returns a serial index number for the year.
214 * <P>
215 * The implementation simply returns the year number (e.g. 2002).
216 *
217 * @return The serial index number.
218 */
219 public long getSerialIndex() {
220 return this.year;
221 }
222
223 /**
224 * Returns the first millisecond of the year, evaluated using the supplied
225 * calendar (which determines the time zone).
226 *
227 * @param calendar the calendar (<code>null</code> not permitted).
228 *
229 * @return The first millisecond of the year.
230 *
231 * @throws NullPointerException if <code>calendar</code> is
232 * <code>null</code>.
233 */
234 public long getFirstMillisecond(Calendar calendar) {
235 calendar.set(this.year, Calendar.JANUARY, 1, 0, 0, 0);
236 calendar.set(Calendar.MILLISECOND, 0);
237 // in the following line, we'd rather call calendar.getTimeInMillis()
238 // to avoid object creation, but that isn't supported in Java 1.3.1
239 return calendar.getTime().getTime();
240 }
241
242 /**
243 * Returns the last millisecond of the year, evaluated using the supplied
244 * calendar (which determines the time zone).
245 *
246 * @param calendar the calendar (<code>null</code> not permitted).
247 *
248 * @return The last millisecond of the year.
249 *
250 * @throws NullPointerException if <code>calendar</code> is
251 * <code>null</code>.
252 */
253 public long getLastMillisecond(Calendar calendar) {
254 calendar.set(this.year, Calendar.DECEMBER, 31, 23, 59, 59);
255 calendar.set(Calendar.MILLISECOND, 999);
256 // in the following line, we'd rather call calendar.getTimeInMillis()
257 // to avoid object creation, but that isn't supported in Java 1.3.1
258 return calendar.getTime().getTime();
259 }
260
261 /**
262 * Tests the equality of this <code>Year</code> object to an arbitrary
263 * object. Returns <code>true</code> if the target is a <code>Year</code>
264 * instance representing the same year as this object. In all other cases,
265 * returns <code>false</code>.
266 *
267 * @param object the object (<code>null</code> permitted).
268 *
269 * @return <code>true</code> if the year of this and the object are the
270 * same.
271 */
272 public boolean equals(Object object) {
273 if (object != null) {
274 if (object instanceof Year) {
275 Year target = (Year) object;
276 return (this.year == target.getYear());
277 }
278 else {
279 return false;
280 }
281 }
282 else {
283 return false;
284 }
285 }
286
287 /**
288 * Returns a hash code for this object instance. The approach described by
289 * Joshua Bloch in "Effective Java" has been used here:
290 * <p>
291 * <code>http://developer.java.sun.com/developer/Books/effectivejava
292 * /Chapter3.pdf</code>
293 *
294 * @return A hash code.
295 */
296 public int hashCode() {
297 int result = 17;
298 int c = this.year;
299 result = 37 * result + c;
300 return result;
301 }
302
303 /**
304 * Returns an integer indicating the order of this <code>Year</code> object
305 * relative to the specified object:
306 *
307 * negative == before, zero == same, positive == after.
308 *
309 * @param o1 the object to compare.
310 *
311 * @return negative == before, zero == same, positive == after.
312 */
313 public int compareTo(Object o1) {
314
315 int result;
316
317 // CASE 1 : Comparing to another Year object
318 // -----------------------------------------
319 if (o1 instanceof Year) {
320 Year y = (Year) o1;
321 result = this.year - y.getYear();
322 }
323
324 // CASE 2 : Comparing to another TimePeriod object
325 // -----------------------------------------------
326 else if (o1 instanceof RegularTimePeriod) {
327 // more difficult case - evaluate later...
328 result = 0;
329 }
330
331 // CASE 3 : Comparing to a non-TimePeriod object
332 // ---------------------------------------------
333 else {
334 // consider time periods to be ordered after general objects
335 result = 1;
336 }
337
338 return result;
339
340 }
341
342 /**
343 * Returns a string representing the year..
344 *
345 * @return A string representing the year.
346 */
347 public String toString() {
348 return Integer.toString(this.year);
349 }
350
351 /**
352 * Parses the string argument as a year.
353 * <P>
354 * The string format is YYYY.
355 *
356 * @param s a string representing the year.
357 *
358 * @return <code>null</code> if the string is not parseable, the year
359 * otherwise.
360 */
361 public static Year parseYear(String s) {
362
363 // parse the string...
364 int y;
365 try {
366 y = Integer.parseInt(s.trim());
367 }
368 catch (NumberFormatException e) {
369 throw new TimePeriodFormatException("Cannot parse string.");
370 }
371
372 // create the year...
373 try {
374 return new Year(y);
375 }
376 catch (IllegalArgumentException e) {
377 throw new TimePeriodFormatException("Year outside valid range.");
378 }
379 }
380
381 }