Glassfish example source code file (MappingElementImpl.java)

This example Glassfish source code file (MappingElementImpl.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 - Glassfish tags/keywords

bean, javabean, mappingelementimpl, mappingelementimpl, modelexception, object, object, propertychangelistener, propertychangesupport, propertyvetoexception, resourcebundle, string, string, text, util, vetoablechangelistener, vetoablechangesupport, vetoablechangesupport

The Glassfish MappingElementImpl.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

/*
 * MappingElementImpl.java
 *
 * Created on March 24, 2000, 10:06 AM
 */

package com.sun.jdo.api.persistence.model.mapping.impl;

import java.beans.*;
import java.util.ResourceBundle;
import java.text.Collator;

import com.sun.jdo.api.persistence.model.ModelException;
import com.sun.jdo.api.persistence.model.ModelVetoException;
import com.sun.jdo.api.persistence.model.mapping.MappingElement;
import org.glassfish.persistence.common.I18NHelper;

/** 
 *
 * @author raccah
 * @version %I%
 */
public abstract class MappingElementImpl implements MappingElement
{
	/** I18N message handler */
	private static final ResourceBundle _messages = I18NHelper.loadBundle(
		"com.sun.jdo.api.persistence.model.Bundle",		// NOI18N
		MappingElementImpl.class.getClassLoader());

	/** Property change support */
	private PropertyChangeSupport _support;

	/** Vetoable change support */
	private transient VetoableChangeSupport _vetoableSupport;

	String _name;

	/** Create new MappingElementImpl with no corresponding name.  This 
	 * constructor should only be used for cloning and archiving.
	 */
	public MappingElementImpl ()
	{
		this(null);
	}

	/** Creates new MappingElementImpl with the corresponding name 
	 * @param name the name of the element
	 */
	public MappingElementImpl (String name)
	{
		super();
		_name = name;
	}

	/** @return I18N message handler for this element
	 */
	protected static final ResourceBundle getMessages () { return _messages; }

	/** Overrides Object's <code>toString method to return the name 
	 * of this mapping element.
	 * @return a string representation of the object
	 */
	public String toString () { return getName(); }

    /** Overrides Object's <code>equals method by comparing the name of this mapping element
     * with the name of the argument obj. The method returns <code>false if obj does not have
     * the same dynamic type as this mapping element.
	 * @return <code>true if this object is the same as the obj argument; false otherwise.
     * @param obj the reference object with which to compare.
     */
    public boolean equals(Object obj)
    {
        if (obj == null)
            return false;
        if (obj == this)
            return true;

        // check for the right class and then do the name check by calling compareTo.
        return (getClass() == obj.getClass()) && (compareTo(obj) == 0);
    }
    
    /** Overrides Object's <code>hashCode method to return the hashCode of this mapping element's name.
     * @return a hash code value for this object.
     */
    public int hashCode()
    {
        return (getName()==null) ? 0 : getName().hashCode();
    }

	/** Fires property change event.
	 * @param name property name
	 * @param o old value
	 * @param n new value
	 */
	protected void firePropertyChange (String name, Object o, Object n)
	{
		if (_support != null)
			_support.firePropertyChange(name, o, n);
	}

	/** Fires vetoable change event.
	 * @param name property name
	 * @param o old value
	 * @param n new value
	 * @exception PropertyVetoException when the change is vetoed by a listener
	 */
	protected void fireVetoableChange (String name, Object o, Object n)
		throws PropertyVetoException
	{
		if (_vetoableSupport != null)
			_vetoableSupport.fireVetoableChange(name, o, n);
	}

	//================= implementation of MappingElement ================

	/** Add a property change listener.
	 * @param l the listener to add
	 */
	public synchronized void addPropertyChangeListener 
		(PropertyChangeListener l)
	{
		if (_support == null)
		{
			synchronized(this)
			{
				// new test under synchronized block
				if (_support == null)
					_support = new PropertyChangeSupport(this);
			}
		}

		_support.addPropertyChangeListener(l);
	}

	/** Remove a property change listener.
	 * @param l the listener to remove
	 */
	public void removePropertyChangeListener (PropertyChangeListener l)
	{
		if (_support != null)
			_support.removePropertyChangeListener(l);
	}

	/** Add a vetoable change listener.
	 * @param l the listener to add
	 */
	public synchronized void addVetoableChangeListener 
		(VetoableChangeListener l)
	{
		if (_vetoableSupport == null)
			_vetoableSupport = new VetoableChangeSupport(this);

		_vetoableSupport.addVetoableChangeListener(l);
	}

	/** Remove a vetoable change listener.
	 * @param l the listener to remove
	 */
	public synchronized void removeVetoableChangeListener (
		VetoableChangeListener l)
	{
		if (_vetoableSupport != null)
			_vetoableSupport.removeVetoableChangeListener(l);
	}

	/** Get the name of this mapping element.
	 * @return the name
	 */
	public String getName () { return _name; }

	/** Set the name of this mapping element.
	 * @param name the name
	 * @exception ModelException if impossible
	 */
	public void setName (String name) throws ModelException
	{
		String old = getName();
		
		try
		{
			fireVetoableChange(PROP_NAME, old, name);
			_name = name;
			firePropertyChange(PROP_NAME, old, name);
		}
		catch (PropertyVetoException e)
		{
			throw new ModelVetoException(e);
		}
	}

	//================= implementation of Comparable ================
    
	/** Compares this object with the specified object for order. Returns a negative integer, zero, 
     * or a positive integer as this object is less than, equal to, or greater than the specified object.
     * The specified object must be mapping element, meaning it must be an instance of class 
     * MappingElementImpl or any subclass. If not a ClassCastException is thrown.
     * The order of MappingElementImpl objects is defined by the order of their names.
     * Mapping elements without name are considered to be less than any named mapping element.
     * @param o the Object to be compared.
     * @return a negative integer, zero, or a positive integer as this object is less than, equal to, 
     * or greater than the specified object.
     * @exception ClassCastException - if the specified object is null or is not an instance of MappingElementImpl
     */
    public int compareTo(Object o)
    {
        // null is not allowed
        if (o == null)
            throw new ClassCastException();
        if (o == this)
            return 0;

        String thisName = getName();
        // the following statement throws a ClassCastException if o is not a MappingElementImpl
        String otherName = ((MappingElementImpl)o).getName();
        // if this does not have a name it should compare less than any named object
        if (thisName == null)
            return (otherName == null) ? 0 : -1;
        // if this is named and o does not have a name it should compare greater
        if (otherName == null)
            return 1;
        // now we know that this and o are named mapping elements => 
        // use locale-sensitive String comparison 
        int ret = Collator.getInstance().compare(thisName, otherName);
        // if both names are equal, both objects might have different types. 
        // If so order both objects by their type names (necessary to be consistent with equals)
        if ((ret == 0) && (getClass() != o.getClass()))
            ret = getClass().getName().compareTo(o.getClass().getName());
        return ret;
    }
    
}