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Java > Open Source Codes > org > apache > torque > oid > IDGeneratorFactory


1 package org.apache.torque.oid;
2
3 /*
4  * Licensed to the Apache Software Foundation (ASF) under one
5  * or more contributor license agreements. See the NOTICE file
6  * distributed with this work for additional information
7  * regarding copyright ownership. The ASF licenses this file
8  * to you under the Apache License, Version 2.0 (the
9  * "License"); you may not use this file except in compliance
10  * with the License. You may obtain a copy of the License at
11  *
12  * http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing,
15  * software distributed under the License is distributed on an
16  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17  * KIND, either express or implied. See the License for the
18  * specific language governing permissions and limitations
19  * under the License.
20  */
21
22 import org.apache.torque.adapter.DB;
23 import org.apache.torque.adapter.IDMethod;
24
25 /**
26  * A factory which instantiates {@link
27  * org.apache.torque.oid.IdGenerator} implementations.
28  *
29  * @author <a HREF="mailto:dlr@collab.net">Daniel Rall</a>
30  * @version $Id: IDGeneratorFactory.java 476550 2006-11-18 16:08:37Z tfischer $
31  */
32 public class IDGeneratorFactory
33 {
34     /**
35      * Private constructor to prevent initialisation.
36      *
37      * This class contains only static methods and thus should not be
38      * instantiated.
39      */
40     private IDGeneratorFactory()
41     {
42     }
43
44     /**
45      * The list of ID generation method types which have associated
46      * {@link org.apache.torque.oid.IdGenerator} implementations.
47      */
48     public static final String JavaDoc[] ID_GENERATOR_METHODS =
49     {
50         IDMethod.NATIVE, IDMethod.AUTO_INCREMENT, IDMethod.SEQUENCE
51     };
52
53     /**
54      * Factory method which instantiates {@link
55      * org.apache.torque.oid.IdGenerator} implementations based on the
56      * return value of the provided adapter's {@link
57      * org.apache.torque.adapter.DB#getIDMethodType()} method.
58      * Returns <code>null</code> for unknown types.
59      *
60      * @param dbAdapter The type of adapter to create an ID generator for.
61      * @return The appropriate ID generator (possibly <code>null</code>).
62      */
63     public static IdGenerator create(DB dbAdapter, String JavaDoc name)
64     {
65         String JavaDoc idMethod = dbAdapter.getIDMethodType();
66         if (IDMethod.AUTO_INCREMENT.equals(idMethod))
67         {
68             return new AutoIncrementIdGenerator(dbAdapter, name);
69         }
70         else if (IDMethod.SEQUENCE.equals(idMethod))
71         {
72             return new SequenceIdGenerator(dbAdapter, name);
73         }
74         else
75         {
76             return null;
77         }
78     }
79 }
80
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