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 *
042 */
043
044 package org.jfree.data.time;
045
046 import java.io.Serializable;
047 import java.text.DateFormat;
048 import java.util.Date;
049
050 import org.jfree.data.Range;
051
052 /**
053 * A range specified in terms of two <code>java.util.Date</code> objects.
054 * Instances of this class are immutable.
055 */
056 public class DateRange extends Range implements Serializable {
057
058 /** For serialization. */
059 private static final long serialVersionUID = -4705682568375418157L;
060
061 /** The lower bound for the range. */
062 private long lowerDate;
063
064 /** The upper bound for the range. */
065 private long upperDate;
066
067 /**
068 * Default constructor.
069 */
070 public DateRange() {
071 this(new Date(0), new Date(1));
072 }
073
074 /**
075 * Constructs a new range.
076 *
077 * @param lower the lower bound (<code>null</code> not permitted).
078 * @param upper the upper bound (<code>null</code> not permitted).
079 */
080 public DateRange(Date lower, Date upper) {
081 super(lower.getTime(), upper.getTime());
082 this.lowerDate = lower.getTime();
083 this.upperDate = upper.getTime();
084 }
085
086 /**
087 * Constructs a new range using two values that will be interpreted as
088 * "milliseconds since midnight GMT, 1-Jan-1970".
089 *
090 * @param lower the lower (oldest) date.
091 * @param upper the upper (most recent) date.
092 */
093 public DateRange(double lower, double upper) {
094 super(lower, upper);
095 this.lowerDate = (long) lower;
096 this.upperDate = (long) upper;
097 }
098
099 /**
100 * Constructs a new range that is based on another {@link Range}. The
101 * other range does not have to be a {@link DateRange}. If it is not, the
102 * upper and lower bounds are evaluated as milliseconds since midnight
103 * GMT, 1-Jan-1970.
104 *
105 * @param other the other range (<code>null</code> not permitted).
106 */
107 public DateRange(Range other) {
108 this(other.getLowerBound(), other.getUpperBound());
109 }
110
111 /**
112 * Returns the lower (earlier) date for the range.
113 *
114 * @return The lower date for the range.
115 */
116 public Date getLowerDate() {
117 return new Date(this.lowerDate);
118 }
119
120 /**
121 * Returns the upper (later) date for the range.
122 *
123 * @return The upper date for the range.
124 */
125 public Date getUpperDate() {
126 return new Date(this.upperDate);
127 }
128
129 /**
130 * Returns a string representing the date range (useful for debugging).
131 *
132 * @return A string representing the date range.
133 */
134 public String toString() {
135 DateFormat df = DateFormat.getDateTimeInstance();
136 return "[" + df.format(getLowerDate()) + " --> "
137 + df.format(getUpperDate()) + "]";
138 }
139
140 }