/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2011, 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.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ----------------------
* DefaultKeyedValue.java
* ----------------------
* (C) Copyright 2002-2008, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes:
* --------
* 31-Oct-2002 : Version 1 (DG);
* 13-Mar-2003 : Added equals() method, and implemented Serializable (DG);
* 18-Aug-2003 : Implemented Cloneable (DG);
* 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.base (DG);
* 15-Sep-2004 : Added PublicCloneable interface (DG);
* ------------- JFREECHART 1.0.x ---------------------------------------------
* 11-Jun-2007 : Added toString() method to help with debugging (DG);
* 15-Feb-2008 : Prevent null key (DG);
* 07-Apr-2008 : Removed to-do item (DG);
*
*/
package org.jfree.data;
import java.io.Serializable;
import org.jfree.util.PublicCloneable;
/**
* A (key, value) pair. This class provides a default implementation
* of the {@link KeyedValue} interface.
*/
public class DefaultKeyedValue implements KeyedValue, Cloneable,
PublicCloneable, Serializable {
/** For serialization. */
private static final long serialVersionUID = -7388924517460437712L;
/** The key. */
private Comparable key;
/** The value. */
private Number value;
/**
* Creates a new (key, value) item.
*
* @param key the key (should be immutable, <code>null</code> not
* permitted).
* @param value the value (<code>null</code> permitted).
*/
public DefaultKeyedValue(Comparable key, Number value) {
if (key == null) {
throw new IllegalArgumentException("Null 'key' argument.");
}
this.key = key;
this.value = value;
}
/**
* Returns the key.
*
* @return The key (never <code>null</code>).
*/
public Comparable getKey() {
return this.key;
}
/**
* Returns the value.
*
* @return The value (possibly <code>null</code>).
*/
public Number getValue() {
return this.value;
}
/**
* Sets the value.
*
* @param value the value (<code>null</code> permitted).
*/
public synchronized void setValue(Number value) {
this.value = value;
}
/**
* Tests this key-value pair for equality with an arbitrary object.
*
* @param obj the object (<code>null</code> permitted).
*
* @return A boolean.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof DefaultKeyedValue)) {
return false;
}
DefaultKeyedValue that = (DefaultKeyedValue) obj;
if (!this.key.equals(that.key)) {
return false;
}
if (this.value != null
? !this.value.equals(that.value) : that.value != null) {
return false;
}
return true;
}
/**
* Returns a hash code.
*
* @return A hash code.
*/
public int hashCode() {
int result;
result = (this.key != null ? this.key.hashCode() : 0);
result = 29 * result + (this.value != null ? this.value.hashCode() : 0);
return result;
}
/**
* Returns a clone. It is assumed that both the key and value are
* immutable objects, so only the references are cloned, not the objects
* themselves.
*
* @return A clone.
*
* @throws CloneNotSupportedException Not thrown by this class, but
* subclasses (if any) might.
*/
public Object clone() throws CloneNotSupportedException {
DefaultKeyedValue clone = (DefaultKeyedValue) super.clone();
return clone;
}
/**
* Returns a string representing this instance, primarily useful for
* debugging.
*
* @return A string.
*/
public String toString() {
return "(" + this.key.toString() + ", " + this.value.toString() + ")";
}
}
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