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jfreechart example source code file (KeyedObjects.java)

This example jfreechart source code file (KeyedObjects.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, comparable, illegalargumentexception, io, iterator, keyedobject, keyedobject, keyedobjects, keyedobjects, list, null, object, object, the, unknownkeyexception, util

The jfreechart KeyedObjects.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.]
 *
 * -----------------
 * KeyedObjects.java
 * -----------------
 * (C) Copyright 2003-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 31-Oct-2002 : Version 1 (DG);
 * 11-Jan-2005 : Minor tidy up (DG);
 * 28-Sep-2007 : Clean up equals() method (DG);
 * 03-Oct-2007 : Make method behaviour consistent with DefaultKeyedValues (DG);
 *
 */

package org.jfree.data;

import java.io.Serializable;
import java.util.Iterator;
import java.util.List;

import org.jfree.util.PublicCloneable;

/**
 * A collection of (key, object) pairs.
 */
public class KeyedObjects implements Cloneable, PublicCloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 1321582394193530984L;

    /** Storage for the data. */
    private List data;

    /**
     * Creates a new collection (initially empty).
     */
    public KeyedObjects() {
        this.data = new java.util.ArrayList();
    }

    /**
     * Returns the number of items (values) in the collection.
     *
     * @return The item count.
     */
    public int getItemCount() {
        return this.data.size();
    }

    /**
     * Returns an object from the list.
     *
     * @param item  the item index (zero-based).
     *
     * @return The object (possibly <code>null).
     *
     * @throws IndexOutOfBoundsException if <code>item is out of bounds.
     */
    public Object getObject(int item) {
        Object result = null;
        KeyedObject kobj = (KeyedObject) this.data.get(item);
        if (kobj != null) {
            result = kobj.getObject();
        }
        return result;
    }

    /**
     * Returns the key at the specified position in the list.
     *
     * @param index  the item index (zero-based).
     *
     * @return The row key.
     *
     * @throws IndexOutOfBoundsException if <code>item is out of bounds.
     *
     * @see #getIndex(Comparable)
     */
    public Comparable getKey(int index) {
        Comparable result = null;
        KeyedObject item = (KeyedObject) this.data.get(index);
        if (item != null) {
            result = item.getKey();
        }
        return result;
    }

    /**
     * Returns the index for a given key, or <code>-1.
     *
     * @param key  the key (<code>null not permitted).
     *
     * @return The index, or <code>-1 if the key is unrecognised.
     *
     * @see #getKey(int)
     */
    public int getIndex(Comparable key) {
        if (key == null) {
            throw new IllegalArgumentException("Null 'key' argument.");
        }
        int i = 0;
        Iterator iterator = this.data.iterator();
        while (iterator.hasNext()) {
            KeyedObject ko = (KeyedObject) iterator.next();
            if (ko.getKey().equals(key)) {
                return i;
            }
            i++;
        }
        return -1;
    }

    /**
     * Returns a list containing all the keys in the list.
     *
     * @return The keys (never <code>null).
     */
    public List getKeys() {
        List result = new java.util.ArrayList();
        Iterator iterator = this.data.iterator();
        while (iterator.hasNext()) {
            KeyedObject ko = (KeyedObject) iterator.next();
            result.add(ko.getKey());
        }
        return result;
    }

    /**
     * Returns the object for a given key. If the key is not recognised, the
     * method should return <code>null.
     *
     * @param key  the key.
     *
     * @return The object (possibly <code>null).
     *
     * @see #addObject(Comparable, Object)
     */
    public Object getObject(Comparable key) {
        int index = getIndex(key);
        if (index < 0) {
            throw new UnknownKeyException("The key (" + key
                    + ") is not recognised.");
        }
        return getObject(index);
    }

    /**
     * Adds a new object to the collection, or overwrites an existing object.
     * This is the same as the {@link #setObject(Comparable, Object)} method.
     *
     * @param key  the key.
     * @param object  the object.
     *
     * @see #getObject(Comparable)
     */
    public void addObject(Comparable key, Object object) {
        setObject(key, object);
    }

    /**
     * Replaces an existing object, or adds a new object to the collection.
     * This is the same as the {@link #addObject(Comparable, Object)}
     * method.
     *
     * @param key  the key (<code>null not permitted).
     * @param object  the object.
     *
     * @see #getObject(Comparable)
     */
    public void setObject(Comparable key, Object object) {
        int keyIndex = getIndex(key);
        if (keyIndex >= 0) {
            KeyedObject ko = (KeyedObject) this.data.get(keyIndex);
            ko.setObject(object);
        }
        else {
            KeyedObject ko = new KeyedObject(key, object);
            this.data.add(ko);
        }
    }

    /**
     * Inserts a new value at the specified position in the dataset or, if
     * there is an existing item with the specified key, updates the value
     * for that item and moves it to the specified position.
     *
     * @param position  the position (in the range <code>0 to
     *                  <code>getItemCount()).
     * @param key  the key (<code>null not permitted).
     * @param value  the value (<code>null permitted).
     *
     * @since 1.0.7
     */
    public void insertValue(int position, Comparable key, Object value) {
        if (position < 0 || position > this.data.size()) {
            throw new IllegalArgumentException("'position' out of bounds.");
        }
        if (key == null) {
            throw new IllegalArgumentException("Null 'key' argument.");
        }
        int pos = getIndex(key);
        if (pos >= 0) {
            this.data.remove(pos);
        }
        KeyedObject item = new KeyedObject(key, value);
        if (position <= this.data.size()) {
            this.data.add(position, item);
        }
        else {
            this.data.add(item);
        }
    }

    /**
     * Removes a value from the collection.
     *
     * @param index  the index of the item to remove.
     *
     * @see #removeValue(Comparable)
     */
    public void removeValue(int index) {
        this.data.remove(index);
    }

    /**
     * Removes a value from the collection.
     *
     * @param key  the key (<code>null not permitted).
     *
     * @see #removeValue(int)
     *
     * @throws UnknownKeyException if the key is not recognised.
     */
    public void removeValue(Comparable key) {
        // defer argument checking
        int index = getIndex(key);
        if (index < 0) {
            throw new UnknownKeyException("The key (" + key.toString()
                    + ") is not recognised.");
        }
        removeValue(index);
    }

    /**
     * Clears all values from the collection.
     *
     * @since 1.0.7
     */
    public void clear() {
        this.data.clear();
    }

    /**
     * Returns a clone of this object.  Keys in the list should be immutable
     * and are not cloned.  Objects in the list are cloned only if they
     * implement {@link PublicCloneable}.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException if there is a problem cloning.
     */
    public Object clone() throws CloneNotSupportedException {
        KeyedObjects clone = (KeyedObjects) super.clone();
        clone.data = new java.util.ArrayList();
        Iterator iterator = this.data.iterator();
        while (iterator.hasNext()) {
            KeyedObject ko = (KeyedObject) iterator.next();
            clone.data.add(ko.clone());
        }
        return clone;
    }

    /**
     * Tests this object for equality with an arbitrary object.
     *
     * @param obj  the object (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {

        if (obj == this) {
            return true;
        }
        if (!(obj instanceof KeyedObjects)) {
            return false;
        }
        KeyedObjects that = (KeyedObjects) obj;
        int count = getItemCount();
        if (count != that.getItemCount()) {
            return false;
        }

        for (int i = 0; i < count; i++) {
            Comparable k1 = getKey(i);
            Comparable k2 = that.getKey(i);
            if (!k1.equals(k2)) {
                return false;
            }
            Object o1 = getObject(i);
            Object o2 = that.getObject(i);
            if (o1 == null) {
                if (o2 != null) {
                    return false;
                }
            }
            else {
                if (!o1.equals(o2)) {
                    return false;
                }
            }
        }
        return true;

    }

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

}

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