Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2013, 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.] * * ---------------- * KeyedObject.java * ---------------- * (C) Copyright 2003-2008, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes: * -------- * 05-Feb-2003 : Version 1 (DG); * 27-Jan-2003 : Implemented Cloneable and Serializable, and added an equals() * method (DG); * */ package org.jfree.data; import java.io.Serializable; import org.jfree.util.ObjectUtilities; import org.jfree.util.PublicCloneable; /** * A (key, object) pair. */ public class KeyedObject implements Cloneable, PublicCloneable, Serializable { /** For serialization. */ private static final long serialVersionUID = 2677930479256885863L; /** The key. */ private Comparable key; /** The object. */ private Object object; /** * Creates a new (key, object) pair. * * @param key the key. * @param object the object (<code>null</code> permitted). */ public KeyedObject(Comparable key, Object object) { this.key = key; this.object = object; } /** * Returns the key. * * @return The key. */ public Comparable getKey() { return this.key; } /** * Returns the object. * * @return The object (possibly <code>null</code>). */ public Object getObject() { return this.object; } /** * Sets the object. * * @param object the object (<code>null</code> permitted). */ public void setObject(Object object) { this.object = object; } /** * Returns a clone of this object. It is assumed that the key is an * immutable object, so it is not deep-cloned. The object is deep-cloned * if it implements {@link PublicCloneable}, otherwise a shallow clone is * made. * * @return A clone. * * @throws CloneNotSupportedException if there is a problem cloning. */ @Override public Object clone() throws CloneNotSupportedException { KeyedObject clone = (KeyedObject) super.clone(); if (this.object instanceof PublicCloneable) { PublicCloneable pc = (PublicCloneable) this.object; clone.object = pc.clone(); } return clone; } /** * Tests if this object is equal to another. * * @param obj the other object. * * @return A boolean. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof KeyedObject)) { return false; } KeyedObject that = (KeyedObject) obj; if (!ObjectUtilities.equal(this.key, that.key)) { return false; } if (!ObjectUtilities.equal(this.object, that.object)) { return false; } return true; } }