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


1 package org.apache.ojb.broker.cache;
2
3 /* Copyright 2002-2005 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.PersistenceBroker;
19 import org.apache.ojb.broker.util.logging.Logger;
20 import org.apache.ojb.broker.util.logging.LoggerFactory;
21
22 /**
23  * Factory for {@link ObjectCache} implementation classes.
24  * Each given {@link org.apache.ojb.broker.PersistenceBroker}
25  * was associated with its own <code>ObjectCache</code> instance
26  * and vice versa.
27  *
28  * @author <a HREF="mailto:thma@apache.org">Thomas Mahler<a>
29  * @version $Id: ObjectCacheFactory.java,v 1.17.2.3 2005/12/21 22:24:15 tomdz Exp $
30  */
31
32 public class ObjectCacheFactory
33 {
34     private Logger log = LoggerFactory.getLogger(ObjectCacheFactory.class);
35
36     private static ObjectCacheFactory singleton = new ObjectCacheFactory();
37
38     /**
39      * Get the ObjectCacheFactory instance.
40      */
41     public static ObjectCacheFactory getInstance()
42     {
43         return singleton;
44     }
45
46     private ObjectCacheFactory()
47     {
48     }
49
50     /**
51      * Creates a new {@link ObjectCacheInternal} instance. Each <tt>ObjectCache</tt>
52      * implementation was wrapped by a {@link CacheDistributor} and the distributor
53      * was wrapped by {@link MaterializationCache}.
54      *
55      * @param broker The PB instance to associate with the cache instance
56      */
57     public MaterializationCache createObjectCache(PersistenceBroker broker)
58     {
59         CacheDistributor cache = null;
60         try
61         {
62             log.info("Start creating new ObjectCache instance");
63             /*
64             1.
65             if default cache was not found,
66             create an new instance of the default cache specified in the
67             configuration.
68             2.
69             Then instantiate AllocatorObjectCache to handle
70             per connection/ per class caching instances.
71             3.
72             To support intern operations we wrap ObjectCache with an
73             InternalObjectCache implementation
74             */
75             cache = new CacheDistributor(broker);
76             log.info("Instantiate new " + cache.getClass().getName() + " for PB instance " + broker);
77         }
78         catch(Exception JavaDoc e)
79         {
80             log.error("Error while initiation, please check your configuration" +
81                     " files and the used implementation class", e);
82         }
83         log.info("New ObjectCache instance was created");
84         return new MaterializationCache(cache);
85     }
86 }
87
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