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     * Hour.java
029     * ---------
030     * (C) Copyright 2001-2009, 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     * 18-Dec-2001 : Changed order of parameters in constructor (DG);
039     * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG);
040     * 14-Feb-2002 : Fixed bug in Hour(Date) constructor (DG);
041     * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to
042     *               evaluate with reference to a particular time zone (DG);
043     * 15-Mar-2002 : Changed API (DG);
044     * 16-Apr-2002 : Fixed small time zone bug in constructor (DG);
045     * 10-Sep-2002 : Added getSerialIndex() method (DG);
046     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
047     * 10-Jan-2003 : Changed base class and method names (DG);
048     * 13-Mar-2003 : Moved to com.jrefinery.data.time package, and implemented
049     *               Serializable (DG);
050     * 21-Oct-2003 : Added hashCode() method, and new constructor for
051     *               convenience (DG);
052     * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG);
053     * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for
054     *               JDK 1.3 (DG);
055     * ------------- JFREECHART 1.0.x ---------------------------------------------
056     * 05-Oct-2006 : Updated API docs (DG);
057     * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG);
058     * 04-Apr-2007 : In Hour(Date, TimeZone), peg milliseconds using specified
059     *               time zone (DG);
060     * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE (DG);
061     * 02-Mar-2009 : 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    /**
074     * Represents an hour in a specific day.  This class is immutable, which is a
075     * requirement for all {@link RegularTimePeriod} subclasses.
076     */
077    public class Hour extends RegularTimePeriod implements Serializable {
078    
079        /** For serialization. */
080        private static final long serialVersionUID = -835471579831937652L;
081    
082        /** Useful constant for the first hour in the day. */
083        public static final int FIRST_HOUR_IN_DAY = 0;
084    
085        /** Useful constant for the last hour in the day. */
086        public static final int LAST_HOUR_IN_DAY = 23;
087    
088        /** The day. */
089        private Day day;
090    
091        /** The hour. */
092        private byte hour;
093    
094        /** The first millisecond. */
095        private long firstMillisecond;
096    
097        /** The last millisecond. */
098        private long lastMillisecond;
099    
100        /**
101         * Constructs a new Hour, based on the system date/time.
102         */
103        public Hour() {
104            this(new Date());
105        }
106    
107        /**
108         * Constructs a new Hour.
109         *
110         * @param hour  the hour (in the range 0 to 23).
111         * @param day  the day (<code>null</code> not permitted).
112         */
113        public Hour(int hour, Day day) {
114            if (day == null) {
115                throw new IllegalArgumentException("Null 'day' argument.");
116            }
117            this.hour = (byte) hour;
118            this.day = day;
119            peg(Calendar.getInstance());
120        }
121    
122        /**
123         * Creates a new hour.
124         *
125         * @param hour  the hour (0-23).
126         * @param day  the day (1-31).
127         * @param month  the month (1-12).
128         * @param year  the year (1900-9999).
129         */
130        public Hour(int hour, int day, int month, int year) {
131            this(hour, new Day(day, month, year));
132        }
133    
134        /**
135         * Constructs a new instance, based on the supplied date/time and
136         * the default time zone.
137         *
138         * @param time  the date-time (<code>null</code> not permitted).
139         *
140         * @see #Hour(Date, TimeZone)
141         */
142        public Hour(Date time) {
143            // defer argument checking...
144            this(time, TimeZone.getDefault(), Locale.getDefault());
145        }
146    
147        /**
148         * Constructs a new instance, based on the supplied date/time evaluated
149         * in the specified time zone.
150         *
151         * @param time  the date-time (<code>null</code> not permitted).
152         * @param zone  the time zone (<code>null</code> not permitted).
153         *
154         * @deprecated As of 1.0.13, use the constructor that specifies the locale
155         *     also.
156         */
157        public Hour(Date time, TimeZone zone) {
158            this(time, zone, Locale.getDefault());
159        }
160    
161        /**
162         * Constructs a new instance, based on the supplied date/time evaluated
163         * in the specified time zone.
164         *
165         * @param time  the date-time (<code>null</code> not permitted).
166         * @param zone  the time zone (<code>null</code> not permitted).
167         * @param locale  the locale (<code>null</code> not permitted).
168         *
169         * @since 1.0.13
170         */
171        public Hour(Date time, TimeZone zone, Locale locale) {
172            if (time == null) {
173                throw new IllegalArgumentException("Null 'time' argument.");
174            }
175            if (zone == null) {
176                throw new IllegalArgumentException("Null 'zone' argument.");
177            }
178            if (locale == null) {
179                throw new IllegalArgumentException("Null 'locale' argument.");
180            }
181            Calendar calendar = Calendar.getInstance(zone, locale);
182            calendar.setTime(time);
183            this.hour = (byte) calendar.get(Calendar.HOUR_OF_DAY);
184            this.day = new Day(time, zone, locale);
185            peg(calendar);
186        }
187    
188        /**
189         * Returns the hour.
190         *
191         * @return The hour (0 <= hour <= 23).
192         */
193        public int getHour() {
194            return this.hour;
195        }
196    
197        /**
198         * Returns the day in which this hour falls.
199         *
200         * @return The day.
201         */
202        public Day getDay() {
203            return this.day;
204        }
205    
206        /**
207         * Returns the year in which this hour falls.
208         *
209         * @return The year.
210         */
211        public int getYear() {
212            return this.day.getYear();
213        }
214    
215        /**
216         * Returns the month in which this hour falls.
217         *
218         * @return The month.
219         */
220        public int getMonth() {
221            return this.day.getMonth();
222        }
223    
224        /**
225         * Returns the day-of-the-month in which this hour falls.
226         *
227         * @return The day-of-the-month.
228         */
229        public int getDayOfMonth() {
230            return this.day.getDayOfMonth();
231        }
232    
233        /**
234         * Returns the first millisecond of the hour.  This will be determined
235         * relative to the time zone specified in the constructor, or in the
236         * calendar instance passed in the most recent call to the
237         * {@link #peg(Calendar)} method.
238         *
239         * @return The first millisecond of the hour.
240         *
241         * @see #getLastMillisecond()
242         */
243        public long getFirstMillisecond() {
244            return this.firstMillisecond;
245        }
246    
247        /**
248         * Returns the last millisecond of the hour.  This will be
249         * determined relative to the time zone specified in the constructor, or
250         * in the calendar instance passed in the most recent call to the
251         * {@link #peg(Calendar)} method.
252         *
253         * @return The last millisecond of the hour.
254         *
255         * @see #getFirstMillisecond()
256         */
257        public long getLastMillisecond() {
258            return this.lastMillisecond;
259        }
260    
261        /**
262         * Recalculates the start date/time and end date/time for this time period
263         * relative to the supplied calendar (which incorporates a time zone).
264         *
265         * @param calendar  the calendar (<code>null</code> not permitted).
266         *
267         * @since 1.0.3
268         */
269        public void peg(Calendar calendar) {
270            this.firstMillisecond = getFirstMillisecond(calendar);
271            this.lastMillisecond = getLastMillisecond(calendar);
272        }
273    
274        /**
275         * Returns the hour preceding this one.
276         *
277         * @return The hour preceding this one.
278         */
279        public RegularTimePeriod previous() {
280            Hour result;
281            if (this.hour != FIRST_HOUR_IN_DAY) {
282                result = new Hour(this.hour - 1, this.day);
283            }
284            else { // we are at the first hour in the day...
285                Day prevDay = (Day) this.day.previous();
286                if (prevDay != null) {
287                    result = new Hour(LAST_HOUR_IN_DAY, prevDay);
288                }
289                else {
290                    result = null;
291                }
292            }
293            return result;
294        }
295    
296        /**
297         * Returns the hour following this one.
298         *
299         * @return The hour following this one.
300         */
301        public RegularTimePeriod next() {
302            Hour result;
303            if (this.hour != LAST_HOUR_IN_DAY) {
304                result = new Hour(this.hour + 1, this.day);
305            }
306            else { // we are at the last hour in the day...
307                Day nextDay = (Day) this.day.next();
308                if (nextDay != null) {
309                    result = new Hour(FIRST_HOUR_IN_DAY, nextDay);
310                }
311                else {
312                    result = null;
313                }
314            }
315            return result;
316        }
317    
318        /**
319         * Returns a serial index number for the hour.
320         *
321         * @return The serial index number.
322         */
323        public long getSerialIndex() {
324            return this.day.getSerialIndex() * 24L + this.hour;
325        }
326    
327        /**
328         * Returns the first millisecond of the hour.
329         *
330         * @param calendar  the calendar/timezone (<code>null</code> not permitted).
331         *
332         * @return The first millisecond.
333         *
334         * @throws NullPointerException if <code>calendar</code> is
335         *     <code>null</code>.
336         */
337        public long getFirstMillisecond(Calendar calendar) {
338            int year = this.day.getYear();
339            int month = this.day.getMonth() - 1;
340            int dom = this.day.getDayOfMonth();
341            calendar.set(year, month, dom, this.hour, 0, 0);
342            calendar.set(Calendar.MILLISECOND, 0);
343            //return calendar.getTimeInMillis();  // this won't work for JDK 1.3
344            return calendar.getTime().getTime();
345        }
346    
347        /**
348         * Returns the last millisecond of the hour.
349         *
350         * @param calendar  the calendar/timezone (<code>null</code> not permitted).
351         *
352         * @return The last millisecond.
353         *
354         * @throws NullPointerException if <code>calendar</code> is
355         *     <code>null</code>.
356         */
357        public long getLastMillisecond(Calendar calendar) {
358            int year = this.day.getYear();
359            int month = this.day.getMonth() - 1;
360            int dom = this.day.getDayOfMonth();
361            calendar.set(year, month, dom, this.hour, 59, 59);
362            calendar.set(Calendar.MILLISECOND, 999);
363            //return calendar.getTimeInMillis();  // this won't work for JDK 1.3
364            return calendar.getTime().getTime();
365        }
366    
367        /**
368         * Tests the equality of this object against an arbitrary Object.
369         * <P>
370         * This method will return true ONLY if the object is an Hour object
371         * representing the same hour as this instance.
372         *
373         * @param obj  the object to compare (<code>null</code> permitted).
374         *
375         * @return <code>true</code> if the hour and day value of the object
376         *      is the same as this.
377         */
378        public boolean equals(Object obj) {
379            if (obj == this) {
380                return true;
381            }
382            if (!(obj instanceof Hour)) {
383                return false;
384            }
385            Hour that = (Hour) obj;
386            if (this.hour != that.hour) {
387                return false;
388            }
389            if (!this.day.equals(that.day)) {
390                return false;
391            }
392            return true;
393        }
394    
395        /**
396         * Returns a string representation of this instance, for debugging
397         * purposes.
398         *
399         * @return A string.
400         */
401        public String toString() {
402            return "[" + this.hour + "," + getDayOfMonth() + "/" + getMonth() + "/"
403                    + getYear() + "]";
404        }
405     
406        /**
407         * Returns a hash code for this object instance.  The approach described by
408         * Joshua Bloch in "Effective Java" has been used here:
409         * <p>
410         * <code>http://developer.java.sun.com/developer/Books/effectivejava
411         * /Chapter3.pdf</code>
412         *
413         * @return A hash code.
414         */
415        public int hashCode() {
416            int result = 17;
417            result = 37 * result + this.hour;
418            result = 37 * result + this.day.hashCode();
419            return result;
420        }
421    
422        /**
423         * Returns an integer indicating the order of this Hour object relative to
424         * the specified object:
425         *
426         * negative == before, zero == same, positive == after.
427         *
428         * @param o1  the object to compare.
429         *
430         * @return negative == before, zero == same, positive == after.
431         */
432        public int compareTo(Object o1) {
433            int result;
434    
435            // CASE 1 : Comparing to another Hour object
436            // -----------------------------------------
437            if (o1 instanceof Hour) {
438                Hour h = (Hour) o1;
439                result = getDay().compareTo(h.getDay());
440                if (result == 0) {
441                    result = this.hour - h.getHour();
442                }
443            }
444    
445            // CASE 2 : Comparing to another TimePeriod object
446            // -----------------------------------------------
447            else if (o1 instanceof RegularTimePeriod) {
448                // more difficult case - evaluate later...
449                result = 0;
450            }
451    
452            // CASE 3 : Comparing to a non-TimePeriod object
453            // ---------------------------------------------
454            else {
455                // consider time periods to be ordered after general objects
456                result = 1;
457            }
458    
459            return result;
460        }
461    
462        /**
463         * Creates an Hour instance by parsing a string.  The string is assumed to
464         * be in the format "YYYY-MM-DD HH", perhaps with leading or trailing
465         * whitespace.
466         *
467         * @param s  the hour string to parse.
468         *
469         * @return <code>null</code> if the string is not parseable, the hour
470         *         otherwise.
471         */
472        public static Hour parseHour(String s) {
473            Hour result = null;
474            s = s.trim();
475    
476            String daystr = s.substring(0, Math.min(10, s.length()));
477            Day day = Day.parseDay(daystr);
478            if (day != null) {
479                String hourstr = s.substring(
480                    Math.min(daystr.length() + 1, s.length()), s.length()
481                );
482                hourstr = hourstr.trim();
483                int hour = Integer.parseInt(hourstr);
484                // if the hour is 0 - 23 then create an hour
485                if ((hour >= FIRST_HOUR_IN_DAY) && (hour <= LAST_HOUR_IN_DAY)) {
486                    result = new Hour(hour, day);
487                }
488            }
489    
490            return result;
491        }
492    
493    }