jfreechart example source code file (ComparableObjectItem.java)

This example jfreechart source code file (ComparableObjectItem.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, clonenotsupportedexception, comparable, comparable, comparableobjectitem, comparableobjectitem, illegalargumentexception, io, null, object, object, serializable

The jfreechart ComparableObjectItem.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.]
 *
 * -------------------------
 * ComparableObjectItem.java
 * -------------------------
 * (C) Copyright 2006-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 19-Oct-2006 : New class, based on XYDataItem (DG);
 *
 */

package org.jfree.data;

import java.io.Serializable;

import org.jfree.util.ObjectUtilities;

/**
 * Represents one (Comparable, Object) data item for use in a
 * {@link ComparableObjectSeries}.
 *
 * @since 1.0.3
 */
public class ComparableObjectItem implements Cloneable, Comparable,
        Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 2751513470325494890L;

    /** The x-value. */
    private Comparable x;

    /** The y-value. */
    private Object obj;

    /**
     * Constructs a new data item.
     *
     * @param x  the x-value (<code>null NOT permitted).
     * @param y  the y-value (<code>null permitted).
     */
    public ComparableObjectItem(Comparable x, Object y) {
        if (x == null) {
            throw new IllegalArgumentException("Null 'x' argument.");
        }
        this.x = x;
        this.obj = y;
    }

    /**
     * Returns the x-value.
     *
     * @return The x-value (never <code>null).
     */
    protected Comparable getComparable() {
        return this.x;
    }

    /**
     * Returns the y-value.
     *
     * @return The y-value (possibly <code>null).
     */
    protected Object getObject() {
        return this.obj;
    }

    /**
     * Sets the y-value for this data item.  Note that there is no
     * corresponding method to change the x-value.
     *
     * @param y  the new y-value (<code>null permitted).
     */
    protected void setObject(Object y) {
        this.obj = y;
    }

    /**
     * Returns an integer indicating the order of this object relative to
     * another object.
     * <P>
     * For the order we consider only the x-value:
     * negative == "less-than", zero == "equal", positive == "greater-than".
     *
     * @param o1  the object being compared to.
     *
     * @return An integer indicating the order of this data pair object
     *      relative to another object.
     */
    public int compareTo(Object o1) {

        int result;

        // CASE 1 : Comparing to another ComparableObjectItem object
        // ---------------------------------------------------------
        if (o1 instanceof ComparableObjectItem) {
            ComparableObjectItem that = (ComparableObjectItem) o1;
            return this.x.compareTo(that.x);
        }

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

        return result;

    }

    /**
     * Returns a clone of this object.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException not thrown by this class, but
     *         subclasses may differ.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    /**
     * Tests if this object is equal to another.
     *
     * @param obj  the object to test against for equality (<code>null
     *             permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof ComparableObjectItem)) {
            return false;
        }
        ComparableObjectItem that = (ComparableObjectItem) obj;
        if (!this.x.equals(that.x)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.obj, that.obj)) {
            return false;
        }
        return true;
    }

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

}