001: /*
002: * $Header: /home/cvs/jakarta-tomcat-4.0/catalina/src/share/org/apache/catalina/util/LifecycleSupport.java,v 1.3 2001/11/09 19:40:54 remm Exp $
003: * $Revision: 1.3 $
004: * $Date: 2001/11/09 19:40:54 $
005: *
006: * ====================================================================
007: *
008: * The Apache Software License, Version 1.1
009: *
010: * Copyright (c) 1999 The Apache Software Foundation. All rights
011: * reserved.
012: *
013: * Redistribution and use in source and binary forms, with or without
014: * modification, are permitted provided that the following conditions
015: * are met:
016: *
017: * 1. Redistributions of source code must retain the above copyright
018: * notice, this list of conditions and the following disclaimer.
019: *
020: * 2. Redistributions in binary form must reproduce the above copyright
021: * notice, this list of conditions and the following disclaimer in
022: * the documentation and/or other materials provided with the
023: * distribution.
024: *
025: * 3. The end-user documentation included with the redistribution, if
026: * any, must include the following acknowlegement:
027: * "This product includes software developed by the
028: * Apache Software Foundation (http://www.apache.org/)."
029: * Alternately, this acknowlegement may appear in the software itself,
030: * if and wherever such third-party acknowlegements normally appear.
031: *
032: * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
033: * Foundation" must not be used to endorse or promote products derived
034: * from this software without prior written permission. For written
035: * permission, please contact apache@apache.org.
036: *
037: * 5. Products derived from this software may not be called "Apache"
038: * nor may "Apache" appear in their names without prior written
039: * permission of the Apache Group.
040: *
041: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
042: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
043: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
044: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
045: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
046: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
047: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
048: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
049: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
050: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
051: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
052: * SUCH DAMAGE.
053: * ====================================================================
054: *
055: * This software consists of voluntary contributions made by many
056: * individuals on behalf of the Apache Software Foundation. For more
057: * information on the Apache Software Foundation, please see
058: * <http://www.apache.org/>.
059: *
060: * [Additional notices, if required by prior licensing conditions]
061: *
062: */
063:
064: package org.apache.catalina.util;
065:
066: import org.apache.catalina.Lifecycle;
067: import org.apache.catalina.LifecycleEvent;
068: import org.apache.catalina.LifecycleListener;
069:
070: /**
071: * Support class to assist in firing LifecycleEvent notifications to
072: * registered LifecycleListeners.
073: *
074: * @author Craig R. McClanahan
075: * @version $Id: LifecycleSupport.java,v 1.3 2001/11/09 19:40:54 remm Exp $
076: */
077:
078: public final class LifecycleSupport {
079:
080: // ----------------------------------------------------------- Constructors
081:
082: /**
083: * Construct a new LifecycleSupport object associated with the specified
084: * Lifecycle component.
085: *
086: * @param lifecycle The Lifecycle component that will be the source
087: * of events that we fire
088: */
089: public LifecycleSupport(Lifecycle lifecycle) {
090:
091: super ();
092: this .lifecycle = lifecycle;
093:
094: }
095:
096: // ----------------------------------------------------- Instance Variables
097:
098: /**
099: * The source component for lifecycle events that we will fire.
100: */
101: private Lifecycle lifecycle = null;
102:
103: /**
104: * The set of registered LifecycleListeners for event notifications.
105: */
106: private LifecycleListener listeners[] = new LifecycleListener[0];
107:
108: // --------------------------------------------------------- Public Methods
109:
110: /**
111: * Add a lifecycle event listener to this component.
112: *
113: * @param listener The listener to add
114: */
115: public void addLifecycleListener(LifecycleListener listener) {
116:
117: synchronized (listeners) {
118: LifecycleListener results[] = new LifecycleListener[listeners.length + 1];
119: for (int i = 0; i < listeners.length; i++)
120: results[i] = listeners[i];
121: results[listeners.length] = listener;
122: listeners = results;
123: }
124:
125: }
126:
127: /**
128: * Get the lifecycle listeners associated with this lifecycle. If this
129: * Lifecycle has no listeners registered, a zero-length array is returned.
130: */
131: public LifecycleListener[] findLifecycleListeners() {
132:
133: return listeners;
134:
135: }
136:
137: /**
138: * Notify all lifecycle event listeners that a particular event has
139: * occurred for this Container. The default implementation performs
140: * this notification synchronously using the calling thread.
141: *
142: * @param type Event type
143: * @param data Event data
144: */
145: public void fireLifecycleEvent(String type, Object data) {
146:
147: LifecycleEvent event = new LifecycleEvent(lifecycle, type, data);
148: LifecycleListener interested[] = null;
149: synchronized (listeners) {
150: interested = (LifecycleListener[]) listeners.clone();
151: }
152: for (int i = 0; i < interested.length; i++)
153: interested[i].lifecycleEvent(event);
154:
155: }
156:
157: /**
158: * Remove a lifecycle event listener from this component.
159: *
160: * @param listener The listener to remove
161: */
162: public void removeLifecycleListener(LifecycleListener listener) {
163:
164: synchronized (listeners) {
165: int n = -1;
166: for (int i = 0; i < listeners.length; i++) {
167: if (listeners[i] == listener) {
168: n = i;
169: break;
170: }
171: }
172: if (n < 0)
173: return;
174: LifecycleListener results[] = new LifecycleListener[listeners.length - 1];
175: int j = 0;
176: for (int i = 0; i < listeners.length; i++) {
177: if (i != n)
178: results[j++] = listeners[i];
179: }
180: listeners = results;
181: }
182:
183: }
184:
185: }
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