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Java > Open Source Codes > org > apache > geronimo > gbean > runtime > GBeanCollectionReference


1 /**
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 package org.apache.geronimo.gbean.runtime;
19
20 import org.apache.geronimo.gbean.AbstractName;
21 import org.apache.geronimo.gbean.GReferenceInfo;
22 import org.apache.geronimo.gbean.InvalidConfigurationException;
23 import org.apache.geronimo.gbean.ReferencePatterns;
24 import org.apache.geronimo.gbean.AbstractNameQuery;
25 import org.apache.geronimo.kernel.Kernel;
26 import org.apache.geronimo.kernel.lifecycle.LifecycleAdapter;
27 import org.apache.geronimo.kernel.lifecycle.LifecycleListener;
28
29 import java.util.Collections JavaDoc;
30 import java.util.HashSet JavaDoc;
31 import java.util.Iterator JavaDoc;
32 import java.util.Set JavaDoc;
33
34 /**
35  * @version $Rev:386515 $ $Date: 2006-11-16 23:35:17 -0500 (Thu, 16 Nov 2006) $
36  */
37 public class GBeanCollectionReference extends AbstractGBeanReference {
38     /**
39      * is this reference online
40      */
41     private boolean isOnline = false;
42
43     /**
44      * The target objectName patterns to watch for a connection.
45      */
46     private Set JavaDoc patterns = Collections.EMPTY_SET;
47
48     /**
49      * Current set of targets
50      */
51     private final Set JavaDoc targets = new HashSet JavaDoc();
52
53     /**
54      * Our listener for lifecycle events
55      */
56     private final LifecycleListener listener;
57
58     public GBeanCollectionReference(GBeanInstance gbeanInstance, GReferenceInfo referenceInfo, Kernel kernel, ReferencePatterns referencePatterns) throws InvalidConfigurationException {
59         super(gbeanInstance, referenceInfo, kernel, hasTargets(referencePatterns));
60         listener = createLifecycleListener();
61         if (referencePatterns != null) {
62             setReferencePatterns(referencePatterns);
63         }
64     }
65
66     private static boolean hasTargets(ReferencePatterns referencePatterns) {
67         if (referencePatterns == null) {
68             return false;
69         }
70         if (referencePatterns.isResolved()) {
71             return true;
72         }
73         return !referencePatterns.getPatterns().isEmpty();
74     }
75
76     public synchronized boolean start() {
77         // We only need to start if there are patterns and we don't already have a proxy
78 if (!patterns.isEmpty() && getProxy() == null) {
79             // add a dependency on our target and create the proxy
80 setProxy(new ProxyCollection(getName(), getReferenceType(), getTargets(), getKernel()));
81         }
82         return true;
83     }
84
85     public synchronized void stop() {
86         ProxyCollection proxy = (ProxyCollection) getProxy();
87         if (proxy != null) {
88             proxy.destroy();
89             setProxy(null);
90         }
91     }
92
93     protected synchronized void targetAdded(AbstractName target) {
94         ProxyCollection proxy = (ProxyCollection) getProxy();
95         if (proxy != null) {
96             proxy.addTarget(target);
97         }
98     }
99
100     protected synchronized void targetRemoved(AbstractName target) {
101         ProxyCollection proxy = (ProxyCollection) getProxy();
102         if (proxy != null) {
103             proxy.removeTarget(target);
104         }
105     }
106
107     protected LifecycleListener createLifecycleListener() {
108         return new LifecycleAdapter() {
109             public void running(AbstractName abstractName) {
110                 addTarget(abstractName);
111             }
112
113             public void stopping(AbstractName abstractName) {
114                 removeTarget(abstractName);
115             }
116
117             public void stopped(AbstractName abstractName) {
118                 removeTarget(abstractName);
119             }
120
121             public void failed(AbstractName abstractName) {
122                 removeTarget(abstractName);
123             }
124
125             public void unloaded(AbstractName abstractName) {
126                 removeTarget(abstractName);
127             }
128         };
129     }
130
131     public final synchronized Set JavaDoc getPatterns() {
132         return patterns;
133     }
134
135     public final synchronized void setReferencePatterns(ReferencePatterns referencePatterns) {
136         if (isOnline) {
137             throw new IllegalStateException JavaDoc("Pattern set can not be modified while online");
138         }
139         if (referencePatterns.isResolved()) {
140             this.patterns = Collections.unmodifiableSet(Collections.singleton(new AbstractNameQuery(referencePatterns.getAbstractName())));
141         } else {
142             this.patterns = Collections.unmodifiableSet(referencePatterns.getPatterns());
143         }
144     }
145
146     public final synchronized void online() {
147         Set JavaDoc gbeans = getKernel().listGBeans(patterns);
148         for (Iterator JavaDoc objectNameIterator = gbeans.iterator(); objectNameIterator.hasNext();) {
149             AbstractName target = (AbstractName) objectNameIterator.next();
150             if (!targets.contains(target)) {
151
152                 // if the bean is running add it to the runningTargets list
153 if (isRunning(getKernel(), target)) {
154                     targets.add(target);
155                 }
156             }
157         }
158
159         getKernel().getLifecycleMonitor().addLifecycleListener(listener, patterns);
160         isOnline = true;
161     }
162
163     public final synchronized void offline() {
164         // make sure we are stoped
165 stop();
166
167         getKernel().getLifecycleMonitor().removeLifecycleListener(listener);
168
169         targets.clear();
170         isOnline = false;
171     }
172
173     protected final Set JavaDoc getTargets() {
174         return targets;
175     }
176
177     protected final void addTarget(AbstractName abstractName) {
178         if (!targets.contains(abstractName)) {
179             targets.add(abstractName);
180             targetAdded(abstractName);
181         }
182     }
183
184     protected final void removeTarget(AbstractName abstractName) {
185         boolean wasTarget = targets.remove(abstractName);
186         if (wasTarget) {
187             targetRemoved(abstractName);
188         }
189     }
190
191 }
192
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