| /* |
| * Copyright (c) 1999, 2000, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.naming.event; |
| |
| import javax.naming.Binding; |
| |
| /** |
| * This class represents an event fired by a naming/directory service. |
| *<p> |
| * The {@code NamingEvent}'s state consists of |
| * <ul> |
| * <li>The event source: the {@code EventContext} which fired this event. |
| * <li>The event type. |
| * <li>The new binding: information about the object after the change. |
| * <li>The old binding: information about the object before the change. |
| * <li>Change information: information about the change |
| * that triggered this event; usually service provider-specific or server-specific |
| * information. |
| * </ul> |
| * <p> |
| * Note that the event source is always the same {@code EventContext} |
| * <em>instance</em> that the listener has registered with. |
| * Furthermore, the names of the bindings in |
| * the {@code NamingEvent} are always relative to that instance. |
| * For example, suppose a listener makes the following registration: |
| *<blockquote><pre> |
| * NamespaceChangeListener listener = ...; |
| * src.addNamingListener("x", SUBTREE_SCOPE, listener); |
| *</pre></blockquote> |
| * When an object named "x/y" is subsequently deleted, the corresponding |
| * {@code NamingEvent} ({@code evt}) must contain: |
| *<blockquote><pre> |
| * evt.getEventContext() == src |
| * evt.getOldBinding().getName().equals("x/y") |
| *</pre></blockquote> |
| * |
| * Care must be taken when multiple threads are accessing the same |
| * {@code EventContext} concurrently. |
| * See the |
| * <a href=package-summary.html#THREADING>package description</a> |
| * for more information on threading issues. |
| * |
| * @author Rosanna Lee |
| * @author Scott Seligman |
| * |
| * @see NamingListener |
| * @see EventContext |
| * @since 1.3 |
| */ |
| public class NamingEvent extends java.util.EventObject { |
| /** |
| * Naming event type for indicating that a new object has been added. |
| * The value of this constant is {@code 0}. |
| */ |
| public static final int OBJECT_ADDED = 0; |
| |
| /** |
| * Naming event type for indicating that an object has been removed. |
| * The value of this constant is {@code 1}. |
| */ |
| public static final int OBJECT_REMOVED = 1; |
| |
| /** |
| * Naming event type for indicating that an object has been renamed. |
| * Note that some services might fire multiple events for a single |
| * logical rename operation. For example, the rename operation might |
| * be implemented by adding a binding with the new name and removing |
| * the old binding. |
| *<p> |
| * The old/new binding in {@code NamingEvent} may be null if the old |
| * name or new name is outside of the scope for which the listener |
| * has registered. |
| *<p> |
| * When an interior node in the namespace tree has been renamed, the |
| * topmost node which is part of the listener's scope should used to generate |
| * a rename event. The extent to which this can be supported is |
| * provider-specific. For example, a service might generate rename |
| * notifications for all descendants of the changed interior node and the |
| * corresponding provider might not be able to prevent those |
| * notifications from being propagated to the listeners. |
| *<p> |
| * The value of this constant is {@code 2}. |
| */ |
| public static final int OBJECT_RENAMED = 2; |
| |
| /** |
| * Naming event type for indicating that an object has been changed. |
| * The changes might include the object's attributes, or the object itself. |
| * Note that some services might fire multiple events for a single |
| * modification. For example, the modification might |
| * be implemented by first removing the old binding and adding |
| * a new binding containing the same name but a different object. |
| *<p> |
| * The value of this constant is {@code 3}. |
| */ |
| public static final int OBJECT_CHANGED = 3; |
| |
| /** |
| * Contains information about the change that generated this event. |
| * @serial |
| */ |
| protected Object changeInfo; |
| |
| /** |
| * Contains the type of this event. |
| * @see #OBJECT_ADDED |
| * @see #OBJECT_REMOVED |
| * @see #OBJECT_RENAMED |
| * @see #OBJECT_CHANGED |
| * @serial |
| */ |
| protected int type; |
| |
| /** |
| * Contains information about the object before the change. |
| * @serial |
| */ |
| protected Binding oldBinding; |
| |
| /** |
| * Contains information about the object after the change. |
| * @serial |
| */ |
| protected Binding newBinding; |
| |
| /** |
| * Constructs an instance of {@code NamingEvent}. |
| *<p> |
| * The names in {@code newBd} and {@code oldBd} are to be resolved relative |
| * to the event source {@code source}. |
| * |
| * For an {@code OBJECT_ADDED} event type, {@code newBd} must not be null. |
| * For an {@code OBJECT_REMOVED} event type, {@code oldBd} must not be null. |
| * For an {@code OBJECT_CHANGED} event type, {@code newBd} and |
| * {@code oldBd} must not be null. For an {@code OBJECT_RENAMED} event type, |
| * one of {@code newBd} or {@code oldBd} may be null if the new or old |
| * binding is outside of the scope for which the listener has registered. |
| * |
| * @param source The non-null context that fired this event. |
| * @param type The type of the event. |
| * @param newBd A possibly null binding before the change. See method description. |
| * @param oldBd A possibly null binding after the change. See method description. |
| * @param changeInfo A possibly null object containing information about the change. |
| * @see #OBJECT_ADDED |
| * @see #OBJECT_REMOVED |
| * @see #OBJECT_RENAMED |
| * @see #OBJECT_CHANGED |
| */ |
| public NamingEvent(EventContext source, int type, |
| Binding newBd, Binding oldBd, Object changeInfo) { |
| super(source); |
| this.type = type; |
| oldBinding = oldBd; |
| newBinding = newBd; |
| this.changeInfo = changeInfo; |
| } |
| |
| /** |
| * Returns the type of this event. |
| * @return The type of this event. |
| * @see #OBJECT_ADDED |
| * @see #OBJECT_REMOVED |
| * @see #OBJECT_RENAMED |
| * @see #OBJECT_CHANGED |
| */ |
| public int getType() { |
| return type; |
| } |
| |
| /** |
| * Retrieves the event source that fired this event. |
| * This returns the same object as {@code EventObject.getSource()}. |
| *<p> |
| * If the result of this method is used to access the |
| * event source, for example, to look up the object or get its attributes, |
| * then it needs to be locked because implementations of {@code Context} |
| * are not guaranteed to be thread-safe |
| * (and {@code EventContext} is a subinterface of {@code Context}). |
| * See the |
| * <a href=package-summary.html#THREADING>package description</a> |
| * for more information on threading issues. |
| * |
| * @return The non-null context that fired this event. |
| */ |
| public EventContext getEventContext() { |
| return (EventContext)getSource(); |
| } |
| |
| /** |
| * Retrieves the binding of the object before the change. |
| *<p> |
| * The binding must be nonnull if the object existed before the change |
| * relative to the source context ({@code getEventContext()}). |
| * That is, it must be nonnull for {@code OBJECT_REMOVED} and |
| * {@code OBJECT_CHANGED}. |
| * For {@code OBJECT_RENAMED}, it is null if the object before the rename |
| * is outside of the scope for which the listener has registered interest; |
| * it is nonnull if the object is inside the scope before the rename. |
| *<p> |
| * The name in the binding is to be resolved relative |
| * to the event source {@code getEventContext()}. |
| * The object returned by {@code Binding.getObject()} may be null if |
| * such information is unavailable. |
| * |
| * @return The possibly null binding of the object before the change. |
| */ |
| public Binding getOldBinding() { |
| return oldBinding; |
| } |
| |
| /** |
| * Retrieves the binding of the object after the change. |
| *<p> |
| * The binding must be nonnull if the object existed after the change |
| * relative to the source context ({@code getEventContext()}). |
| * That is, it must be nonnull for {@code OBJECT_ADDED} and |
| * {@code OBJECT_CHANGED}. For {@code OBJECT_RENAMED}, |
| * it is null if the object after the rename is outside the scope for |
| * which the listener registered interest; it is nonnull if the object |
| * is inside the scope after the rename. |
| *<p> |
| * The name in the binding is to be resolved relative |
| * to the event source {@code getEventContext()}. |
| * The object returned by {@code Binding.getObject()} may be null if |
| * such information is unavailable. |
| * |
| * @return The possibly null binding of the object after the change. |
| */ |
| public Binding getNewBinding() { |
| return newBinding; |
| } |
| |
| /** |
| * Retrieves the change information for this event. |
| * The value of the change information is service-specific. For example, |
| * it could be an ID that identifies the change in a change log on the server. |
| * |
| * @return The possibly null change information of this event. |
| */ |
| public Object getChangeInfo() { |
| return changeInfo; |
| } |
| |
| /** |
| * Invokes the appropriate listener method on this event. |
| * The default implementation of |
| * this method handles the following event types: |
| * {@code OBJECT_ADDED, OBJECT_REMOVED, |
| * OBJECT_RENAMED, OBJECT_CHANGED}. |
| *<p> |
| * The listener method is executed in the same thread |
| * as this method. See the |
| * <a href=package-summary.html#THREADING>package description</a> |
| * for more information on threading issues. |
| * @param listener The nonnull listener. |
| */ |
| public void dispatch(NamingListener listener) { |
| switch (type) { |
| case OBJECT_ADDED: |
| ((NamespaceChangeListener)listener).objectAdded(this); |
| break; |
| |
| case OBJECT_REMOVED: |
| ((NamespaceChangeListener)listener).objectRemoved(this); |
| break; |
| |
| case OBJECT_RENAMED: |
| ((NamespaceChangeListener)listener).objectRenamed(this); |
| break; |
| |
| case OBJECT_CHANGED: |
| ((ObjectChangeListener)listener).objectChanged(this); |
| break; |
| } |
| } |
| private static final long serialVersionUID = -7126752885365133499L; |
| } |