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Java > Open Source Codes > org > apache > ojb > broker > cache > ObjectCacheJCSPerClassImpl


1 package org.apache.ojb.broker.cache;
2
3 /* Copyright 2003-2005 The Apache Software Foundation
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * 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 import org.apache.ojb.broker.Identity;
19 import org.apache.ojb.broker.PersistenceBroker;
20 import org.apache.ojb.broker.util.logging.LoggerFactory;
21
22 import java.util.HashMap JavaDoc;
23 import java.util.Iterator JavaDoc;
24 import java.util.Map JavaDoc;
25 import java.util.Properties JavaDoc;
26
27 /**
28  * A global {@link ObjectCache} implementation using a JCS region for
29  * each class. Each class name was associated with a dedicated
30  * {@link ObjectCacheJCSImpl} instance to cache given objects.
31  * This allows to define JCS cache region configuration properties
32  * for each used class in JCS configuration files.
33  *
34  * <br/>
35  * More info see <a HREF="http://jakarta.apache.org/turbine/jcs/index.html">
36  * turbine-JCS</a>.
37  *
38  * <p>
39  * Implementation configuration properties:
40  * </p>
41  *
42  * <table cellspacing="2" cellpadding="2" border="3" frame="box">
43  * <tr>
44  * <td><strong>Property Key</strong></td>
45  * <td><strong>Property Values</strong></td>
46  * </tr>
47  * <tr>
48  * <td> - </td>
49  * <td>
50  * -
51  * </td>
52  * </tr>
53  * </table>
54  *
55  * @author Matthew Baird (mattbaird@yahoo.com)
56  * @author <a HREF="mailto:armin@codeAuLait.de">Armin Waibel</a>
57  * @version $Id: ObjectCacheJCSPerClassImpl.java,v 1.3.2.1 2005/12/21 22:24:15 tomdz Exp $
58  */
59
60 public class ObjectCacheJCSPerClassImpl extends AbstractMetaCache
61 {
62     private static Map JavaDoc cachesByClass = new HashMap JavaDoc();
63
64     /**
65      * Constructor for the MetaObjectCachePerClassImpl object
66      */
67     public ObjectCacheJCSPerClassImpl(PersistenceBroker broker, Properties JavaDoc prop)
68     {
69     }
70
71     public ObjectCache getCache(Identity oid, Object JavaDoc obj, int methodCall)
72     {
73         if (oid.getObjectsRealClass() == null)
74         {
75             LoggerFactory.getDefaultLogger().info("[" + this.getClass()
76                     + "] Can't get JCS cache, real class was 'null' for Identity: " + oid);
77             return null;
78         }
79         return getCachePerClass(oid.getObjectsRealClass(), methodCall);
80     }
81
82     /**
83      * Clears the cache
84      */
85     public void clear()
86     {
87         Iterator JavaDoc it = cachesByClass.values().iterator();
88         while (it.hasNext())
89         {
90             ObjectCache cache = (ObjectCache) it.next();
91             if (cache != null)
92             {
93                 cache.clear();
94             }
95             else
96             {
97                 it.remove();
98             }
99         }
100     }
101
102     /**
103      * Gets the cache for the given class
104      *
105      * @param objectClass The class to look up the cache for
106      * @return The cache
107      */
108     private ObjectCache getCachePerClass(Class JavaDoc objectClass, int methodCall)
109     {
110         ObjectCache cache = (ObjectCache) cachesByClass.get(objectClass.getName());
111         if (cache == null && methodCall == AbstractMetaCache.METHOD_CACHE)
112         {
113             /**
114              * the cache wasn't found, and the cachesByClass didn't contain the key with a
115              * null value, so create a new cache for this classtype
116              */
117             cache = new ObjectCacheJCSImpl(objectClass.getName());
118             cachesByClass.put(objectClass.getName(), cache);
119         }
120         return cache;
121     }
122 }
123
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