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 java.util.ArrayList;
23 import java.util.Collections;
24 import java.util.List;
25
26 import org.apache.torque.adapter.Adapter;
27 import org.apache.torque.adapter.IDMethod;
28
29 /**
30 * A factory which instantiates {@link
31 * org.apache.torque.oid.IdGenerator} implementations.
32 *
33 * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>
34 * @version $Id: IDGeneratorFactory.java 1375892 2012-08-22 04:11:33Z tfischer $
35 */
36 public final class IDGeneratorFactory
37 {
38 /**
39 * The list of ID generation method types which have associated
40 * {@link org.apache.torque.oid.IdGenerator} implementations.
41 */
42 public static final List<IDMethod> ID_GENERATOR_METHODS;
43
44 static
45 {
46 List<IDMethod> idGeneratorMethods = new ArrayList<IDMethod>();
47 idGeneratorMethods.add(IDMethod.NATIVE);
48 idGeneratorMethods.add(IDMethod.AUTO_INCREMENT);
49 idGeneratorMethods.add(IDMethod.SEQUENCE);
50 ID_GENERATOR_METHODS = Collections.unmodifiableList(idGeneratorMethods);
51 }
52
53 /**
54 * Private constructor to prevent initialisation.
55 *
56 * This class contains only static methods and thus should not be
57 * instantiated.
58 */
59 private IDGeneratorFactory()
60 {
61 // empty
62 }
63
64 /**
65 * Factory method which instantiates {@link
66 * org.apache.torque.oid.IdGenerator} implementations based on the
67 * return value of the provided adapter's {@link
68 * org.apache.torque.adapter.Adapter#getIDMethodType()} method.
69 * Returns <code>null</code> for unknown types.
70 *
71 * @param adapter The type of adapter to create an ID generator for.
72 *
73 * @return The appropriate ID generator (possibly <code>null</code>).
74 */
75 public static IdGenerator create(Adapter adapter, String name)
76 {
77 IDMethod idMethod = adapter.getIDMethodType();
78 if (IDMethod.AUTO_INCREMENT == idMethod)
79 {
80 return new AutoIncrementIdGenerator(adapter, name);
81 }
82 else if (IDMethod.SEQUENCE == idMethod)
83 {
84 return new SequenceIdGenerator(adapter, name);
85 }
86 else
87 {
88 return null;
89 }
90 }
91 }