1 /**
2 * Copyright 2003-2007 Greg Luck
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package net.sf.ehcache.event;
18
19 import net.sf.ehcache.CacheException;
20 import net.sf.ehcache.Status;
21
22 import java.util.ArrayList;
23 import java.util.List;
24
25
26 /**
27 * A counting cache manager listener.
28 * @author Greg Luck
29 * @version $Id: CountingCacheManagerEventListener.java 512 2007-07-10 09:18:45Z gregluck $
30 */
31 public class CountingCacheManagerEventListener implements CacheManagerEventListener {
32
33
34 private static List cacheNamesAdded = new ArrayList();
35 private static List cacheNamesRemoved = new ArrayList();
36
37 /**
38 * Accessor
39 */
40 public static List getCacheNamesAdded() {
41 return cacheNamesAdded;
42 }
43
44 /**
45 * Resets the counters to 0
46 */
47 public static void resetCounters() {
48 cacheNamesAdded.clear();
49 cacheNamesRemoved.clear();
50 }
51
52 /**
53 * Accessor
54 */
55 public static List getCacheNamesRemoved() {
56 return cacheNamesRemoved;
57 }
58
59 /**
60 * Call to start the listeners and do any other required initialisation.
61 *
62 * @throws net.sf.ehcache.CacheException - all exceptions are wrapped in CacheException
63 */
64 public void init() throws CacheException {
65 //noop
66 }
67
68 /**
69 * Returns the listener status.
70 *
71 * @return the status at the point in time the method is called
72 */
73 public Status getStatus() {
74 return Status.STATUS_ALIVE;
75 }
76
77 /**
78 * Stop the listener and free any resources.
79 *
80 * @throws net.sf.ehcache.CacheException - all exceptions are wrapped in CacheException
81 */
82 public void dispose() throws CacheException {
83 //noop
84 }
85
86 /**
87 * Called immediately after a cache has been added and activated.
88 * <p/>
89 * Note that the CacheManager calls this method from a synchronized method. Any attempt to call a synchronized
90 * method on CacheManager from this method will cause a deadlock.
91 * <p/>
92 * Note that activation will also cause a CacheEventListener status change notification from
93 * {@link net.sf.ehcache.Status#STATUS_UNINITIALISED} to {@link net.sf.ehcache.Status#STATUS_ALIVE}. Care should be
94 * taken on processing that notification because:
95 * <ul>
96 * <li>the cache will not yet be accessible from the CacheManager.
97 * <li>the addCaches methods whih cause this notification are synchronized on the CacheManager. An attempt to call
98 * {@link net.sf.ehcache.CacheManager#getCache(String)} will cause a deadlock.
99 * </ul>
100 * The calling method will block until this method returns.
101 * <p/>
102 *
103 * @param cacheName the name of the <code>Cache</code> the operation relates to
104 * @see net.sf.ehcache.event.CacheEventListener
105 */
106 public void notifyCacheAdded(String cacheName) {
107 cacheNamesAdded.add(cacheName);
108 }
109
110 /**
111 * Called immediately after a cache has been disposed and removed. The calling method will block until
112 * this method returns.
113 * <p/>
114 * Note that the CacheManager calls this method from a synchronized method. Any attempt to call a synchronized
115 * method on CacheManager from this method will cause a deadlock.
116 * <p/>
117 * Note that a {@link net.sf.ehcache.event.CacheEventListener} status changed will also be triggered. Any attempt from that notification
118 * to access CacheManager will also result in a deadlock.
119 *
120 * @param cacheName the name of the <code>Cache</code> the operation relates to
121 */
122 public void notifyCacheRemoved(String cacheName) {
123 cacheNamesRemoved.add(cacheName);
124 }
125 }