jfreechart example source code file (SimpleTimePeriod.java)

This example jfreechart source code file (SimpleTimePeriod.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

comparable, date, date, illegalargumentexception, io, requires, serializable, serializable, simpletimeperiod, simpletimeperiod, timeperiod, timeperiod, util

The jfreechart SimpleTimePeriod.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * ---------------------
 * SimpleTimePeriod.java
 * ---------------------
 * (C) Copyright 2002-2008, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 07-Oct-2002 : Added Javadocs (DG);
 * 10-Jan-2003 : Renamed TimeAllocation --> SimpleTimePeriod (DG);
 * 13-Mar-2003 : Added equals() method, and Serializable interface (DG);
 * 21-Oct-2003 : Added hashCode() method (DG);
 * 27-Jan-2005 : Implemented Comparable, to enable this class to be used
 *               in the TimeTableXYDataset class (DG);
 * 02-Jun-2008 : Fixed problem with fields being mutable (DG);
 *
 */

package org.jfree.data.time;

import java.io.Serializable;
import java.util.Date;

/**
 * An arbitrary period of time, measured to millisecond precision using
 * <code>java.util.Date.
 * <p>
 * This class is intentionally immutable (that is, once constructed, you cannot
 * alter the start and end attributes).
 */
public class SimpleTimePeriod implements TimePeriod, Comparable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 8684672361131829554L;

    /** The start date/time. */
    private long start;

    /** The end date/time. */
    private long end;

    /**
     * Creates a new time allocation.
     *
     * @param start  the start date/time in milliseconds.
     * @param end  the end date/time in milliseconds.
     */
    public SimpleTimePeriod(long start, long end) {
        if (start > end) {
            throw new IllegalArgumentException("Requires start <= end.");
        }
        this.start = start;
        this.end = end;
    }

    /**
     * Creates a new time allocation.
     *
     * @param start  the start date/time (<code>null not permitted).
     * @param end  the end date/time (<code>null not permitted).
     */
    public SimpleTimePeriod(Date start, Date end) {
        this(start.getTime(), end.getTime());
    }

    /**
     * Returns the start date/time.
     *
     * @return The start date/time (never <code>null).
     */
    public Date getStart() {
        return new Date(this.start);
    }

    /**
     * Returns the start date/time in milliseconds.
     *
     * @return The start.
     *
     * @since 1.0.10.
     */
    public long getStartMillis() {
        return this.start;
    }

    /**
     * Returns the end date/time.
     *
     * @return The end date/time (never <code>null).
     */
    public Date getEnd() {
        return new Date(this.end);
    }

    /**
     * Returns the end date/time in milliseconds.
     *
     * @return The end.
     *
     * @since 1.0.10.
     */
    public long getEndMillis() {
        return this.end;
    }

    /**
     * Tests this time period instance for equality with an arbitrary object.
     * The object is considered equal if it is an instance of {@link TimePeriod}
     * and it has the same start and end dates.
     *
     * @param obj  the other object (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof TimePeriod)) {
            return false;
        }
        TimePeriod that = (TimePeriod) obj;
        if (!this.getStart().equals(that.getStart())) {
            return false;
        }
        if (!this.getEnd().equals(that.getEnd())) {
            return false;
        }
        return true;
    }

    /**
     * Returns an integer that indicates the relative ordering of two
     * time periods.
     *
     * @param obj  the object (<code>null not permitted).
     *
     * @return An integer.
     *
     * @throws ClassCastException if <code>obj is not an instance of
     *                            {@link TimePeriod}.
     */
    public int compareTo(Object obj) {
        TimePeriod that = (TimePeriod) obj;
        long t0 = getStart().getTime();
        long t1 = getEnd().getTime();
        long m0 = t0 + (t1 - t0) / 2L;
        long t2 = that.getStart().getTime();
        long t3 = that.getEnd().getTime();
        long m1 = t2 + (t3 - t2) / 2L;
        if (m0 < m1) {
            return -1;
        }
        else if (m0 > m1) {
            return 1;
        }
        else {
            if (t0 < t2) {
                return -1;
            }
            else if (t0 > t2) {
                return 1;
            }
            else {
                if (t1 < t3) {
                    return -1;
                }
                else if (t1 > t3) {
                    return 1;
                }
                else {
                    return 0;
                }
            }
        }
    }

    /**
     * Returns a hash code for this object instance.  The approach described by
     * Joshua Bloch in "Effective Java" has been used here - see:
     * <p>
     * <code>http://developer.java.sun.com/
     * developer/Books/effectivejava/Chapter3.pdf</code>
     *
     * @return A hash code.
     */
    public int hashCode() {
        int result = 17;
        result = 37 * result + (int) this.start;
        result = 37 * result + (int) this.end;
        return result;
    }

}