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     * DateRange.java
029     * --------------
030     * (C) Copyright 2002-2008, by Object Refinery Limited and Contributors.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   Bill Kelemen;
034     *
035     * Changes
036     * -------
037     * 22-Apr-2002 : Version 1 based on code by Bill Kelemen (DG);
038     * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
039     * 23-Sep-2003 : Minor Javadoc update (DG);
040     * 28-May-2008 : Fixed problem with immutability (DG);
041     * 01-Sep-2008 : Added getLowerMillis() and getUpperMillis() (DG);
042     *
043     */
044    
045    package org.jfree.data.time;
046    
047    import java.io.Serializable;
048    import java.text.DateFormat;
049    import java.util.Date;
050    
051    import org.jfree.data.Range;
052    
053    /**
054     * A range specified in terms of two <code>java.util.Date</code> objects.
055     * Instances of this class are immutable.
056     */
057    public class DateRange extends Range implements Serializable {
058    
059        /** For serialization. */
060        private static final long serialVersionUID = -4705682568375418157L;
061    
062        /** The lower bound for the range. */
063        private long lowerDate;
064    
065        /** The upper bound for the range. */
066        private long upperDate;
067    
068        /**
069         * Default constructor.
070         */
071        public DateRange() {
072            this(new Date(0), new Date(1));
073        }
074    
075        /**
076         * Constructs a new range.
077         *
078         * @param lower  the lower bound (<code>null</code> not permitted).
079         * @param upper  the upper bound (<code>null</code> not permitted).
080         */
081        public DateRange(Date lower, Date upper) {
082            super(lower.getTime(), upper.getTime());
083            this.lowerDate = lower.getTime();
084            this.upperDate = upper.getTime();
085        }
086    
087        /**
088         * Constructs a new range using two values that will be interpreted as
089         * "milliseconds since midnight GMT, 1-Jan-1970".
090         *
091         * @param lower  the lower (oldest) date.
092         * @param upper  the upper (most recent) date.
093         */
094        public DateRange(double lower, double upper) {
095            super(lower, upper);
096            this.lowerDate = (long) lower;
097            this.upperDate = (long) upper;
098        }
099    
100        /**
101         * Constructs a new range that is based on another {@link Range}.  The
102         * other range does not have to be a {@link DateRange}.  If it is not, the
103         * upper and lower bounds are evaluated as milliseconds since midnight
104         * GMT, 1-Jan-1970.
105         *
106         * @param other  the other range (<code>null</code> not permitted).
107         */
108        public DateRange(Range other) {
109            this(other.getLowerBound(), other.getUpperBound());
110        }
111    
112        /**
113         * Returns the lower (earlier) date for the range.
114         *
115         * @return The lower date for the range.
116         *
117         * @see #getLowerMillis()
118         */
119        public Date getLowerDate() {
120            return new Date(this.lowerDate);
121        }
122    
123        /**
124         * Returns the lower bound of the range in milliseconds.
125         *
126         * @return The lower bound.
127         *
128         * @see #getLowerDate()
129         *
130         * @since 1.0.11
131         */
132        public long getLowerMillis() {
133            return this.lowerDate;
134        }
135    
136        /**
137         * Returns the upper (later) date for the range.
138         *
139         * @return The upper date for the range.
140         *
141         * @see #getUpperMillis()
142         */
143        public Date getUpperDate() {
144            return new Date(this.upperDate);
145        }
146    
147        /**
148         * Returns the upper bound of the range in milliseconds.
149         *
150         * @return The upper bound.
151         *
152         * @see #getUpperDate()
153         *
154         * @since 1.0.11
155         */
156        public long getUpperMillis() {
157            return this.upperDate;
158        }
159    
160        /**
161         * Returns a string representing the date range (useful for debugging).
162         *
163         * @return A string representing the date range.
164         */
165        public String toString() {
166            DateFormat df = DateFormat.getDateTimeInstance();
167            return "[" + df.format(getLowerDate()) + " --> "
168                    + df.format(getUpperDate()) + "]";
169        }
170    
171    }