jfreechart example source code file (TimeSeriesDataItem.java)

This example jfreechart source code file (TimeSeriesDataItem.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

cloneable, clonenotsupportedexception, comparable, illegalargumentexception, io, null, number, number, object, object, regulartimeperiod, regulartimeperiod, serializable, timeseriesdataitem, timeseriesdataitem

The jfreechart TimeSeriesDataItem.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.]
 *
 * -----------------------
 * TimeSeriesDataItem.java
 * -----------------------
 * (C) Copyright 2001-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 11-Oct-2001 : Version 1 (DG);
 * 15-Nov-2001 : Updated Javadoc comments (DG);
 * 29-Nov-2001 : Added cloning (DG);
 * 24-Jun-2002 : Removed unnecessary import (DG);
 * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 13-Mar-2003 : Renamed TimeSeriesDataPair --> TimeSeriesDataItem, moved to
 *               com.jrefinery.data.time package, implemented Serializable (DG)
 */

package org.jfree.data.time;

import java.io.Serializable;

/**
 * Represents one data item in a time series.
 * <P>
 * The time period can be any of the following:
 * <ul>
 * <li>{@link Year}
 * <li>{@link Quarter}
 * <li>{@link Month}
 * <li>{@link Week}
 * <li>{@link Day}
 * <li>{@link Hour}
 * <li>{@link Minute}
 * <li>{@link Second}
 * <li>{@link Millisecond}
 * <li>{@link FixedMillisecond}
 * </ul>
 *
 * The time period is an immutable property of the data item.  Data items will
 * often be sorted within a list, and allowing the time period to be changed
 * could destroy the sort order.
 * <P>
 * Implements the <code>Comparable interface so that standard Java
 * sorting can be used to keep the data items in order.
 *
 */
public class TimeSeriesDataItem implements Cloneable, Comparable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -2235346966016401302L;

    /** The time period. */
    private RegularTimePeriod period;

    /** The value associated with the time period. */
    private Number value;

    /**
     * Constructs a new data item that associates a value with a time period.
     *
     * @param period  the time period (<code>null not permitted).
     * @param value  the value (<code>null permitted).
     */
    public TimeSeriesDataItem(RegularTimePeriod period, Number value) {
        if (period == null) {
            throw new IllegalArgumentException("Null 'period' argument.");
        }
        this.period = period;
        this.value = value;
    }

    /**
     * Constructs a new data item that associates a value with a time period.
     *
     * @param period  the time period (<code>null not permitted).
     * @param value  the value associated with the time period.
     */
    public TimeSeriesDataItem(RegularTimePeriod period, double value) {
        this(period, new Double(value));
    }

    /**
     * Returns the time period.
     *
     * @return The time period (never <code>null).
     */
    public RegularTimePeriod getPeriod() {
        return this.period;
    }

    /**
     * Returns the value.
     *
     * @return The value (<code>null possible).
     */
    public Number getValue() {
        return this.value;
    }

    /**
     * Sets the value for this data item.
     *
     * @param value  the value (<code>null permitted).
     */
    public void setValue(Number value) {
        this.value = value;
    }

    /**
     * Tests this object for equality with an arbitrary object.
     *
     * @param o  the other object.
     *
     * @return A boolean.
     */
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof TimeSeriesDataItem)) {
            return false;
        }
        TimeSeriesDataItem timeSeriesDataItem = (TimeSeriesDataItem) o;
        if (this.period != null) {
            if (!this.period.equals(timeSeriesDataItem.period)) {
                return false;
            }
        }
        else if (timeSeriesDataItem.period != null) {
           return false;
        }

        if (this.value != null) {
            if (!this.value.equals(timeSeriesDataItem.value)) {
                return false;
            }
        }
        else if (timeSeriesDataItem.value != null) {
            return false;
        }

        return true;
    }

    /**
     * Returns a hash code.
     *
     * @return A hash code.
     */
    public int hashCode() {
        int result;
        result = (this.period != null ? this.period.hashCode() : 0);
        result = 29 * result + (this.value != null ? this.value.hashCode() : 0);
        return result;
    }

    /**
     * Returns an integer indicating the order of this data pair object
     * relative to another object.
     * <P>
     * For the order we consider only the timing:
     * negative == before, zero == same, positive == after.
     *
     * @param o1  The object being compared to.
     *
     * @return An integer indicating the order of the data item object
     *         relative to another object.
     */
    public int compareTo(Object o1) {

        int result;

        // CASE 1 : Comparing to another TimeSeriesDataItem object
        // -------------------------------------------------------
        if (o1 instanceof TimeSeriesDataItem) {
            TimeSeriesDataItem datapair = (TimeSeriesDataItem) o1;
            result = getPeriod().compareTo(datapair.getPeriod());
        }

        // CASE 2 : Comparing to a general object
        // ---------------------------------------------
        else {
            // consider time periods to be ordered after general objects
            result = 1;
        }

        return result;

    }

    /**
     * Clones the data item.  Note: there is no need to clone the period or
     * value since they are immutable classes.
     *
     * @return A clone of the data item.
     */
    public Object clone() {
        Object clone = null;
        try {
            clone = super.clone();
        }
        catch (CloneNotSupportedException e) { // won't get here...
            e.printStackTrace();
        }
        return clone;
    }

}