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
050package org.jfree.data.time;
051
052import java.io.Serializable;
053import java.util.Calendar;
054import 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 */
061public 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}