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1: /* =========================================================== 2: * JFreeChart : a free chart library for the Java(tm) platform 3: * =========================================================== 4: * 5: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. 6: * 7: * Project Info: http://www.jfree.org/jfreechart/index.html 8: * 9: * This library is free software; you can redistribute it and/or modify it 10: * under the terms of the GNU Lesser General Public License as published by 11: * the Free Software Foundation; either version 2.1 of the License, or 12: * (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but 15: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 16: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 17: * License for more details. 18: * 19: * You should have received a copy of the GNU Lesser General Public 20: * License along with this library; if not, write to the Free Software 21: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 22: * USA. 23: * 24: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 25: * in the United States and other countries.] 26: * 27: * --------------------- 28: * SimpleTimePeriod.java 29: * --------------------- 30: * (C) Copyright 2002-2005, by Object Refinery Limited and Contributors. 31: * 32: * Original Author: David Gilbert (for Object Refinery Limited); 33: * Contributor(s): -; 34: * 35: * $Id: SimpleTimePeriod.java,v 1.5.2.1 2005/10/25 21:35:24 mungady Exp $ 36: * 37: * Changes 38: * ------- 39: * 07-Oct-2002 : Added Javadocs (DG); 40: * 10-Jan-2003 : Renamed TimeAllocation --> SimpleTimePeriod (DG); 41: * 13-Mar-2003 : Added equals() method, and Serializable interface (DG); 42: * 21-Oct-2003 : Added hashCode() method (DG); 43: * 27-Jan-2005 : Implemented Comparable, to enable this class to be used 44: * in the TimeTableXYDataset class (DG); 45: * 46: */ 47: 48: package org.jfree.data.time; 49: 50: import java.io.Serializable; 51: import java.util.Date; 52: 53: /** 54: * An arbitrary period of time, measured to millisecond precision using 55: * <code>java.util.Date</code>. 56: * <p> 57: * This class is intentionally immutable (that is, once constructed, you cannot 58: * alter the start and end attributes). 59: */ 60: public class SimpleTimePeriod implements TimePeriod, Comparable, Serializable { 61: 62: /** For serialization. */ 63: private static final long serialVersionUID = 8684672361131829554L; 64: 65: /** The start date/time. */ 66: private Date start; 67: 68: /** The end date/time. */ 69: private Date end; 70: 71: /** 72: * Creates a new time allocation. 73: * 74: * @param start the start date/time in milliseconds. 75: * @param end the end date/time in milliseconds. 76: */ 77: public SimpleTimePeriod(long start, long end) { 78: this(new Date(start), new Date(end)); 79: } 80: 81: /** 82: * Creates a new time allocation. 83: * 84: * @param start the start date/time (<code>null</code> not permitted). 85: * @param end the end date/time (<code>null</code> not permitted). 86: */ 87: public SimpleTimePeriod(Date start, Date end) { 88: if (start.getTime() > end.getTime()) { 89: throw new IllegalArgumentException("Requires end >= start."); 90: } 91: this.start = start; 92: this.end = end; 93: } 94: 95: /** 96: * Returns the start date/time. 97: * 98: * @return The start date/time (never <code>null</code>). 99: */ 100: public Date getStart() { 101: return this.start; 102: } 103: 104: /** 105: * Returns the end date/time. 106: * 107: * @return The end date/time (never <code>null</code>). 108: */ 109: public Date getEnd() { 110: return this.end; 111: } 112: 113: /** 114: * Tests this time period instance for equality with an arbitrary object. 115: * The object is considered equal if it is an instance of {@link TimePeriod} 116: * and it has the same start and end dates. 117: * 118: * @param obj the other object (<code>null</code> permitted). 119: * 120: * @return A boolean. 121: */ 122: public boolean equals(Object obj) { 123: if (obj == this) { 124: return true; 125: } 126: if (!(obj instanceof TimePeriod)) { 127: return false; 128: } 129: TimePeriod that = (TimePeriod) obj; 130: if (!this.start.equals(that.getStart())) { 131: return false; 132: } 133: if (!this.end.equals(that.getEnd())) { 134: return false; 135: } 136: return true; 137: } 138: 139: /** 140: * Returns an integer that indicates the relative ordering of two 141: * time periods. 142: * 143: * @param obj the object (<code>null</code> not permitted). 144: * 145: * @return An integer. 146: * 147: * @throws ClassCastException if <code>obj</code> is not an instance of 148: * {@link TimePeriod}. 149: */ 150: public int compareTo(Object obj) { 151: TimePeriod that = (TimePeriod) obj; 152: long t0 = getStart().getTime(); 153: long t1 = getEnd().getTime(); 154: long m0 = t0 + (t1 - t0) / 2L; 155: long t2 = that.getStart().getTime(); 156: long t3 = that.getEnd().getTime(); 157: long m1 = t2 + (t3 - t2) / 2L; 158: if (m0 < m1) { 159: return -1; 160: } 161: else if (m0 > m1) { 162: return 1; 163: } 164: else { 165: if (t0 < t2) { 166: return -1; 167: } 168: else if (t0 > t2) { 169: return 1; 170: } 171: else { 172: if (t1 < t3) { 173: return -1; 174: } 175: else if (t1 > t3) { 176: return 1; 177: } 178: else { 179: return 0; 180: } 181: } 182: } 183: } 184: 185: /** 186: * Returns a hash code for this object instance. The approach described by 187: * Joshua Bloch in "Effective Java" has been used here - see: 188: * <p> 189: * <code>http://developer.java.sun.com/ 190: * developer/Books/effectivejava/Chapter3.pdf</code> 191: * 192: * @return A hash code. 193: */ 194: public int hashCode() { 195: int result = 17; 196: result = 37 * result + this.start.hashCode(); 197: result = 37 * result + this.end.hashCode(); 198: return result; 199: } 200: 201: }