001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 2002-2007, 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 *
041 */
042
043package org.jfree.data.time;
044
045import java.io.Serializable;
046import java.text.DateFormat;
047import java.util.Date;
048
049import org.jfree.data.Range;
050
051/**
052 * A range specified in terms of two <code>java.util.Date</code> objects.  
053 * Instances of this class are immutable.
054 */
055public class DateRange extends Range implements Serializable {
056
057    /** For serialization. */
058    private static final long serialVersionUID = -4705682568375418157L;
059    
060    /** The lower bound for the range. */
061    private Date lowerDate;
062
063    /** The upper bound for the range. */
064    private Date upperDate;
065
066    /**
067     * Default constructor.
068     */
069    public DateRange() {
070        this(new Date(0), new Date(1));
071    }
072
073    /**
074     * Constructs a new range.
075     *
076     * @param lower  the lower bound (<code>null</code> not permitted).
077     * @param upper  the upper bound (<code>null</code> not permitted).
078     */
079    public DateRange(Date lower, Date upper) {
080
081        super(lower.getTime(), upper.getTime());
082        this.lowerDate = lower;
083        this.upperDate = upper;
084
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 = new Date((long) lower);
097        this.upperDate = new Date((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    public Date getLowerDate() {
118        return this.lowerDate;
119    }
120
121    /**
122     * Returns the upper (later) date for the range.
123     *
124     * @return The upper date for the range.
125     */
126    public Date getUpperDate() {
127        return this.upperDate;
128    }
129    
130    /**
131     * Returns a string representing the date range (useful for debugging).
132     * 
133     * @return A string representing the date range.
134     */
135    public String toString() {
136        DateFormat df = DateFormat.getDateTimeInstance();
137        return "[" + df.format(this.lowerDate) + " --> " 
138            + df.format(this.upperDate) + "]";
139    }
140
141}