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.] * * --------------------- * TimePeriodAnchor.java * --------------------- * (C) Copyright 2003-2008, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes: * -------- * 30-Jul-2003 : Version 1 (DG); * 01-Mar-2004 : Added readResolve() method (DG); * */ package org.jfree.data.time; import java.io.ObjectStreamException; import java.io.Serializable; /** * Used to indicate one of three positions in a time period: * <code>START</code>, <code>MIDDLE</code> and <code>END</code>. */ public final class TimePeriodAnchor implements Serializable { /** For serialization. */ private static final long serialVersionUID = 2011955697457548862L; /** Start of period. */ public static final TimePeriodAnchor START = new TimePeriodAnchor("TimePeriodAnchor.START"); /** Middle of period. */ public static final TimePeriodAnchor MIDDLE = new TimePeriodAnchor("TimePeriodAnchor.MIDDLE"); /** End of period. */ public static final TimePeriodAnchor END = new TimePeriodAnchor("TimePeriodAnchor.END"); /** The name. */ private String name; /** * Private constructor. * * @param name the name. */ private TimePeriodAnchor(String name) { this.name = name; } /** * Returns a string representing the object. * * @return The string. */ @Override public String toString() { return this.name; } /** * Returns <code>true</code> if this object is equal to the specified * object, and <code>false</code> otherwise. * * @param obj the other object. * * @return A boolean. */ @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (!(obj instanceof TimePeriodAnchor)) { return false; } TimePeriodAnchor position = (TimePeriodAnchor) obj; if (!this.name.equals(position.name)) { return false; } return true; } /** * Returns a hash code value for the object. * * @return The hashcode */ @Override public int hashCode() { return this.name.hashCode(); } /** * Ensures that serialization returns the unique instances. * * @return The object. * * @throws ObjectStreamException if there is a problem. */ private Object readResolve() throws ObjectStreamException { if (this.equals(TimePeriodAnchor.START)) { return TimePeriodAnchor.START; } else if (this.equals(TimePeriodAnchor.MIDDLE)) { return TimePeriodAnchor.MIDDLE; } else if (this.equals(TimePeriodAnchor.END)) { return TimePeriodAnchor.END; } return null; } }