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Java > Open Source Codes > org > mr > core > persistent > PersistentManagerFactory


1 /*
2  * Copyright 2002 by
3  * <a HREF="http://www.coridan.com">Coridan</a>
4  * <a HREF="mailto: support@coridan.com ">support@coridan.com</a>
5  *
6  * The contents of this file are subject to the Mozilla Public License Version
7  * 1.1 (the "License"); you may not use this file except in compliance with the
8  * License. You may obtain a copy of the License at
9  * http://www.mozilla.org/MPL/
10  *
11  * Software distributed under the License is distributed on an "AS IS" basis,
12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13  * for the specific language governing rights and limitations under the
14  * License.
15  *
16  * The Original Code is "MantaRay" (TM).
17  *
18  * The Initial Developer of the Original Code is Amir Shevat.
19  * Portions created by the Initial Developer are Copyright (C) 2006
20  * Coridan Inc. All Rights Reserved.
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22  * Contributor(s): all the names of the contributors are added in the source
23  * code where applicable.
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25  * Alternatively, the contents of this file may be used under the terms of the
26  * LGPL license (the "GNU LESSER GENERAL PUBLIC LICENSE"), in which case the
27  * provisions of LGPL are applicable instead of those above. If you wish to
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29  * License and not to allow others to use your version of this file under
30  * the MPL, indicate your decision by deleting the provisions above and
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32  * If you do not delete the provisions above, a recipient may use your version
33  * of this file under either the MPL or the GNU LESSER GENERAL PUBLIC LICENSE.
34
35  *
36  * This library is free software; you can redistribute it and/or modify it
37  * under the terms of the MPL as stated above or under the terms of the GNU
38  * Lesser General Public License as published by the Free Software Foundation;
39  * either version 2.1 of the License, or any later version.
40  *
41  * This library is distributed in the hope that it will be useful, but WITHOUT
42  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
43  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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45  */
46 package org.mr.core.persistent;
47
48 import java.util.HashMap JavaDoc;
49 import java.util.WeakHashMap JavaDoc;
50
51 import org.apache.commons.logging.Log;
52 import org.apache.commons.logging.LogFactory;
53 import org.mr.MantaAgent;
54 import org.mr.core.configuration.ConfigManager;
55 import org.mr.core.persistent.db.DBPersistencyManager;
56 import org.mr.core.persistent.db.DBPersistencyProxy;
57 import org.mr.core.persistent.file.*;
58
59 /**
60  * returns a new pesistentManager (today a new MantaFileManager)
61  *
62  * @author Amir Shevat
63  */
64 public class PersistentManagerFactory {
65     public static String JavaDoc backend = null;
66     public static WeakHashMap JavaDoc fileManagers = new WeakHashMap JavaDoc();
67
68     /**
69      * start to manage the domain (this might be a table name in the DB or a file/files name)
70      *
71      * @param persistentName the name of the persistent logical name
72      * (e.g. when queue name is q1 then the persistent topic will be q1)
73      */
74     public static synchronized PersistentManager getPersistentManager(String JavaDoc persistentName) {
75         synchronized (PersistentManagerFactory.class) {
76             if (backend == null) {
77                 ConfigManager config = MantaAgent.getInstance().getSingletonRepository().getConfigManager();
78                 backend =
79                         config.getStringProperty("persistency.backend", "file");
80             }
81         }
82         if (backend.equals("db")) {
83             return new DBPersistencyManager(persistentName);
84         } else {
85             // use file persistancy by default
86 MantaFileManager result = (MantaFileManager) fileManagers.get(persistentName);
87             if (result == null) {
88                 result = new MantaFileManager(new String JavaDoc(persistentName));
89                 fileManagers.put(persistentName, result);
90             }
91             if (!backend.equals("file")) {
92                 Log log = LogFactory.getLog("PersistentManagerFactory");
93                 if (log.isWarnEnabled()) {
94                     log.warn("Unknown backend: " + backend + ". Using file persistency by default.");
95                 }
96             }
97             return result;
98         }
99     }
100
101     //used for retrieving the list of services
102 private static PersistentManager pm = null;
103
104     public static String JavaDoc[] getAllServices() {
105
106         if (pm == null) {
107             synchronized (PersistentManagerFactory.class) {
108                 if (pm == null) {
109                     if (backend == null) {
110                         ConfigManager config = MantaAgent.getInstance().getSingletonRepository().getConfigManager();
111                         backend = config.getStringProperty("persistency.backend", "file");
112                     }
113
114                     if (backend.equals("db")) {
115                         pm = new DBPersistencyManager();
116                     } else {
117                         pm = new MantaFileManager();
118                         if (!backend.equals("file")) {
119                             Log log = LogFactory.getLog("PersistentManagerFactory");
120                             if (log.isWarnEnabled()) {
121                                 log.warn("Unknown backend: " + backend + ". Using file persistency by default.");
122                             }
123                         }
124
125
126                     }
127                 }
128             }
129         }
130         String JavaDoc services[] = pm.getAllServices();
131         return services;
132     }
133 }
134
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