001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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 2002-2005 by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: FixedMillisecond.java,v 1.4.2.1 2005/10/25 21:35:24 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 19-Mar-2002 : Version 1, based on original Millisecond implementation (DG);
040     * 24-Jun-2002 : Removed unnecessary imports (DG);
041     * 10-Sep-2002 : Added getSerialIndex() method (DG);
042     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
043     * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented 
044     *               Serializable (DG);
045     * 21-Oct-2003 : Added hashCode() method (DG);
046     *
047     */
048    
049    package org.jfree.data.time;
050    
051    import java.io.Serializable;
052    import java.util.Calendar;
053    import java.util.Date;
054    
055    /**
056     * Wrapper for a <code>java.util.Date</code> object that allows it to be used 
057     * as a {@link RegularTimePeriod}.  This class is immutable, which is a 
058     * requirement for all {@link RegularTimePeriod} subclasses.
059     */
060    public class FixedMillisecond extends RegularTimePeriod 
061                                  implements Serializable {
062    
063        /** For serialization. */
064        private static final long serialVersionUID = 7867521484545646931L;
065        
066        /** The millisecond. */
067        private Date time;
068    
069        /**
070         * Constructs a millisecond based on the current system time.
071         */
072        public FixedMillisecond() {
073            this(new Date());
074        }
075    
076        /**
077         * Constructs a millisecond.
078         *
079         * @param millisecond  the millisecond (same encoding as java.util.Date).
080         */
081        public FixedMillisecond(long millisecond) {
082            this(new Date(millisecond));
083        }
084    
085        /**
086         * Constructs a millisecond.
087         *
088         * @param time  the time.
089         */
090        public FixedMillisecond(Date time) {
091            this.time = time;
092        }
093    
094        /**
095         * Returns the date/time.
096         *
097         * @return The date/time.
098         */
099        public Date getTime() {
100            return this.time;
101        }
102    
103        /**
104         * Returns the millisecond preceding this one.
105         *
106         * @return The millisecond preceding this one.
107         */
108        public RegularTimePeriod previous() {
109            RegularTimePeriod result = null;
110            long t = this.time.getTime();
111            if (t != Long.MIN_VALUE) {
112                result = new FixedMillisecond(t - 1);
113            }
114            return result;
115        }
116    
117        /**
118         * Returns the millisecond following this one.
119         *
120         * @return The millisecond following this one.
121         */
122        public RegularTimePeriod next() {
123            RegularTimePeriod result = null;
124            long t = this.time.getTime();
125            if (t != Long.MAX_VALUE) {
126                result = new FixedMillisecond(t + 1);
127            }
128            return result;
129        }
130    
131        /**
132         * Tests the equality of this object against an arbitrary Object.
133         *
134         * @param object  the object to compare
135         *
136         * @return A boolean.
137         */
138        public boolean equals(Object object) {
139            if (object instanceof FixedMillisecond) {
140                FixedMillisecond m = (FixedMillisecond) object;
141                return this.time.equals(m.getTime());
142            }
143            else {
144                return false;
145            }
146    
147        }
148    
149        /**
150         * Returns a hash code for this object instance.
151         * 
152         * @return A hash code.
153         */
154        public int hashCode() {
155            return this.time.hashCode();
156        }
157    
158        /**
159         * Returns an integer indicating the order of this Millisecond object
160         * relative to the specified
161         * object: negative == before, zero == same, positive == after.
162         *
163         * @param o1    the object to compare.
164         *
165         * @return negative == before, zero == same, positive == after.
166         */
167        public int compareTo(Object o1) {
168    
169            int result;
170            long difference;
171    
172            // CASE 1 : Comparing to another Second object
173            // -------------------------------------------
174            if (o1 instanceof FixedMillisecond) {
175                FixedMillisecond t1 = (FixedMillisecond) o1;
176                difference = this.time.getTime() - t1.time.getTime();
177                if (difference > 0) {
178                    result = 1;
179                }
180                else {
181                    if (difference < 0) {
182                       result = -1;
183                    }
184                    else {
185                        result = 0;
186                    }
187                }
188            }
189    
190            // CASE 2 : Comparing to another TimePeriod object
191            // -----------------------------------------------
192            else if (o1 instanceof RegularTimePeriod) {
193                // more difficult case - evaluate later...
194                result = 0;
195            }
196    
197            // CASE 3 : Comparing to a non-TimePeriod object
198            // ---------------------------------------------
199            else {
200                // consider time periods to be ordered after general objects
201                result = 1;
202            }
203    
204            return result;
205    
206        }
207    
208        /**
209         * Returns the first millisecond of the time period.
210         *
211         * @return The first millisecond of the time period.
212         */
213        public long getFirstMillisecond() {
214            return this.time.getTime();
215        }
216    
217    
218        /**
219         * Returns the first millisecond of the time period.
220         *
221         * @param calendar  the calendar.
222         *
223         * @return The first millisecond of the time period.
224         */
225        public long getFirstMillisecond(Calendar calendar) {
226            return this.time.getTime();
227        }
228    
229        /**
230         * Returns the last millisecond of the time period.
231         *
232         * @return The last millisecond of the time period.
233         */
234        public long getLastMillisecond() {
235            return this.time.getTime();
236        }
237    
238        /**
239         * Returns the last millisecond of the time period.
240         *
241         * @param calendar  the calendar.
242         *
243         * @return The last millisecond of the time period.
244         */
245        public long getLastMillisecond(Calendar calendar) {
246            return this.time.getTime();
247        }
248    
249        /**
250         * Returns the millisecond closest to the middle of the time period.
251         *
252         * @return The millisecond closest to the middle of the time period.
253         */
254        public long getMiddleMillisecond() {
255            return this.time.getTime();
256        }
257    
258        /**
259         * Returns the millisecond closest to the middle of the time period.
260         *
261         * @param calendar  the calendar.
262         *
263         * @return The millisecond closest to the middle of the time period.
264         */
265        public long getMiddleMillisecond(Calendar calendar) {
266            return this.time.getTime();
267        }
268    
269        /**
270         * Returns a serial index number for the millisecond.
271         *
272         * @return The serial index number.
273         */
274        public long getSerialIndex() {
275            return this.time.getTime();
276        }
277    
278    }