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Java > Open Source Codes > org > apache > torque > engine > platform > PlatformFactory


1 package org.apache.torque.engine.platform;
2
3 /*
4  * Copyright 2003,2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import java.util.HashMap JavaDoc;
20
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23
24 /**
25  * Factory class responsible to create Platform objects that
26  * define RDBMS platform specific behaviour.
27  *
28  * @author Thomas Mahler
29  * @author <a HREF="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
30  * @version $Id: PlatformFactory.java,v 1.2 2004/02/22 06:27:19 jmcnally Exp $
31  */
32 public class PlatformFactory
33 {
34     private static HashMap JavaDoc platforms = new HashMap JavaDoc();
35     private static Log log = LogFactory.getLog(PlatformFactory.class);
36
37     /**
38      * Returns the Platform for a platform name.
39      *
40      * @param dbms name of the platform
41      */
42     public static Platform getPlatformFor(String JavaDoc dbms)
43     {
44         Platform result = null;
45         String JavaDoc platformName = null;
46
47         result = (Platform) getPlatforms().get(dbms);
48         if (result == null)
49         {
50             try
51             {
52                 platformName = getClassnameFor(dbms);
53                 Class JavaDoc platformClass = Class.forName(platformName);
54                 result = (Platform) platformClass.newInstance();
55
56             }
57             catch (Throwable JavaDoc t)
58             {
59                 log.warn("problems with platform " + platformName
60                         + ": " + t.getMessage());
61                 log.warn("Torque will use PlatformDefaultImpl instead");
62
63                 result = new PlatformDefaultImpl();
64             }
65             getPlatforms().put(dbms, result); // cache the Platform
66 }
67         return result;
68     }
69
70     /**
71      * compute the name of the concrete Class representing the Platform
72      * specified by <code>platform</code>
73      *
74      * @param platform the name of the platform as specified in the repository
75      */
76     private static String JavaDoc getClassnameFor(String JavaDoc platform)
77     {
78         String JavaDoc pf = "Default";
79         if (platform != null)
80         {
81             pf = platform;
82         }
83         return "org.apache.torque.engine.platform.Platform" + pf.substring(0, 1).toUpperCase() + pf.substring(1) + "Impl";
84     }
85
86     /**
87      * Gets the platforms.
88      *
89      * @return Returns a HashMap
90      */
91     private static HashMap JavaDoc getPlatforms()
92     {
93         return platforms;
94     }
95 }
96
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