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     * FixedMillisecond.java
029     * ---------------------
030     * (C) Copyright 2002-2008, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * Changes
036     * -------
037     * 19-Mar-2002 : Version 1, based on original Millisecond implementation (DG);
038     * 24-Jun-2002 : Removed unnecessary imports (DG);
039     * 10-Sep-2002 : Added getSerialIndex() method (DG);
040     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
041     * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented
042     *               Serializable (DG);
043     * 21-Oct-2003 : Added hashCode() method (DG);
044     * ------------- JFREECHART 1.0.x ---------------------------------------------
045     * 06-Oct-2006 : Added peg() method (DG);
046     * 28-May-2008 : Fixed immutability problem (DG);
047     *
048     */
049    
050    package org.jfree.data.time;
051    
052    import java.io.Serializable;
053    import java.util.Calendar;
054    import java.util.Date;
055    
056    /**
057     * Wrapper for a <code>java.util.Date</code> object that allows it to be used
058     * as a {@link RegularTimePeriod}.  This class is immutable, which is a
059     * requirement for all {@link RegularTimePeriod} subclasses.
060     */
061    public class FixedMillisecond extends RegularTimePeriod
062            implements Serializable {
063    
064        /** For serialization. */
065        private static final long serialVersionUID = 7867521484545646931L;
066    
067        /** The millisecond. */
068        private long time;
069    
070        /**
071         * Constructs a millisecond based on the current system time.
072         */
073        public FixedMillisecond() {
074            this(new Date());
075        }
076    
077        /**
078         * Constructs a millisecond.
079         *
080         * @param millisecond  the millisecond (same encoding as java.util.Date).
081         */
082        public FixedMillisecond(long millisecond) {
083            this(new Date(millisecond));
084        }
085    
086        /**
087         * Constructs a millisecond.
088         *
089         * @param time  the time.
090         */
091        public FixedMillisecond(Date time) {
092            this.time = time.getTime();
093        }
094    
095        /**
096         * Returns the date/time.
097         *
098         * @return The date/time.
099         */
100        public Date getTime() {
101            return new Date(this.time);
102        }
103    
104        /**
105         * This method is overridden to do nothing.
106         *
107         * @param calendar  ignored
108         *
109         * @since 1.0.3
110         */
111        public void peg(Calendar calendar) {
112            // nothing to do
113        }
114    
115        /**
116         * Returns the millisecond preceding this one.
117         *
118         * @return The millisecond preceding this one.
119         */
120        public RegularTimePeriod previous() {
121            RegularTimePeriod result = null;
122            long t = this.time;
123            if (t != Long.MIN_VALUE) {
124                result = new FixedMillisecond(t - 1);
125            }
126            return result;
127        }
128    
129        /**
130         * Returns the millisecond following this one.
131         *
132         * @return The millisecond following this one.
133         */
134        public RegularTimePeriod next() {
135            RegularTimePeriod result = null;
136            long t = this.time;
137            if (t != Long.MAX_VALUE) {
138                result = new FixedMillisecond(t + 1);
139            }
140            return result;
141        }
142    
143        /**
144         * Tests the equality of this object against an arbitrary Object.
145         *
146         * @param object  the object to compare
147         *
148         * @return A boolean.
149         */
150        public boolean equals(Object object) {
151            if (object instanceof FixedMillisecond) {
152                FixedMillisecond m = (FixedMillisecond) object;
153                return this.time == m.getFirstMillisecond();
154            }
155            else {
156                return false;
157            }
158    
159        }
160    
161        /**
162         * Returns a hash code for this object instance.
163         *
164         * @return A hash code.
165         */
166        public int hashCode() {
167            return (int) this.time;
168        }
169    
170        /**
171         * Returns an integer indicating the order of this Millisecond object
172         * relative to the specified
173         * object: negative == before, zero == same, positive == after.
174         *
175         * @param o1    the object to compare.
176         *
177         * @return negative == before, zero == same, positive == after.
178         */
179        public int compareTo(Object o1) {
180    
181            int result;
182            long difference;
183    
184            // CASE 1 : Comparing to another Second object
185            // -------------------------------------------
186            if (o1 instanceof FixedMillisecond) {
187                FixedMillisecond t1 = (FixedMillisecond) o1;
188                difference = this.time - t1.time;
189                if (difference > 0) {
190                    result = 1;
191                }
192                else {
193                    if (difference < 0) {
194                       result = -1;
195                    }
196                    else {
197                        result = 0;
198                    }
199                }
200            }
201    
202            // CASE 2 : Comparing to another TimePeriod object
203            // -----------------------------------------------
204            else if (o1 instanceof RegularTimePeriod) {
205                // more difficult case - evaluate later...
206                result = 0;
207            }
208    
209            // CASE 3 : Comparing to a non-TimePeriod object
210            // ---------------------------------------------
211            else {
212                // consider time periods to be ordered after general objects
213                result = 1;
214            }
215    
216            return result;
217    
218        }
219    
220        /**
221         * Returns the first millisecond of the time period.
222         *
223         * @return The first millisecond of the time period.
224         */
225        public long getFirstMillisecond() {
226            return this.time;
227        }
228    
229    
230        /**
231         * Returns the first millisecond of the time period.
232         *
233         * @param calendar  the calendar.
234         *
235         * @return The first millisecond of the time period.
236         */
237        public long getFirstMillisecond(Calendar calendar) {
238            return this.time;
239        }
240    
241        /**
242         * Returns the last millisecond of the time period.
243         *
244         * @return The last millisecond of the time period.
245         */
246        public long getLastMillisecond() {
247            return this.time;
248        }
249    
250        /**
251         * Returns the last millisecond of the time period.
252         *
253         * @param calendar  the calendar.
254         *
255         * @return The last millisecond of the time period.
256         */
257        public long getLastMillisecond(Calendar calendar) {
258            return this.time;
259        }
260    
261        /**
262         * Returns the millisecond closest to the middle of the time period.
263         *
264         * @return The millisecond closest to the middle of the time period.
265         */
266        public long getMiddleMillisecond() {
267            return this.time;
268        }
269    
270        /**
271         * Returns the millisecond closest to the middle of the time period.
272         *
273         * @param calendar  the calendar.
274         *
275         * @return The millisecond closest to the middle of the time period.
276         */
277        public long getMiddleMillisecond(Calendar calendar) {
278            return this.time;
279        }
280    
281        /**
282         * Returns a serial index number for the millisecond.
283         *
284         * @return The serial index number.
285         */
286        public long getSerialIndex() {
287            return this.time;
288        }
289    
290    }