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Java > Open Source Codes > org > apache > ojb > otm > kit > SimpleKit


1 package org.apache.ojb.otm.kit;
2
3 /* Copyright 2003-2005 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.Identity;
19 import org.apache.ojb.otm.OTMKit;
20 import org.apache.ojb.otm.copy.*;
21 import org.apache.ojb.otm.lock.map.InMemoryLockMap;
22 import org.apache.ojb.otm.lock.map.LockMap;
23 import org.apache.ojb.otm.lock.wait.LockWaitStrategy;
24 import org.apache.ojb.otm.lock.wait.TimeoutStrategy;
25 import org.apache.ojb.otm.swizzle.CopySwizzling;
26 import org.apache.ojb.otm.swizzle.Swizzling;
27 import org.apache.ojb.otm.transaction.LocalTransactionFactory;
28 import org.apache.ojb.otm.transaction.TransactionFactory;
29
30 import java.io.Serializable JavaDoc;
31
32 /**
33  * A base implementation of an OTMKit using local transactions, an
34  * in-memory lock map, and metadata based object copying for
35  * object swizzling in transactional contexts.
36  *
37  * @author <a HREF="mailto:rraghuram@hotmail.com">Raghu Rajah</a>
38  */
39 public class SimpleKit extends OTMKit
40 {
41
42     private static SimpleKit _instance;
43
44     protected TransactionFactory _txFactory;
45     protected Swizzling _swizzlingStrategy;
46     protected LockWaitStrategy _lockWaitStrategy;
47     protected LockMap _lockMap;
48     protected ObjectCopyStrategy _noOpCopyStrategy;
49     protected ObjectCopyStrategy _defaultCopyStrategy;
50     protected ObjectCopyStrategy _cloneableCopyStrategy;
51
52     /**
53      * Constructor for SimpleKit.
54      */
55     protected SimpleKit()
56     {
57         super();
58         _txFactory = new LocalTransactionFactory();
59         _swizzlingStrategy = new CopySwizzling();
60         _lockWaitStrategy = new TimeoutStrategy();
61         _lockMap = new InMemoryLockMap();
62         _noOpCopyStrategy = new NoOpObjectCopyStrategy();
63         //_defaultCopyStrategy = new ReflectiveObjectCopyStrategy();
64 //_defaultCopyStrategy = new SerializeObjectCopyStrategy();
65 _defaultCopyStrategy = new MetadataObjectCopyStrategy();
66         _cloneableCopyStrategy = new CloneableObjectCopyStrategy();
67     }
68
69     /**
70      * Obtain the single instance of SimpleKit
71      */
72     public static SimpleKit getInstance()
73     {
74         if (_instance == null)
75         {
76             _instance = new SimpleKit();
77         }
78         return _instance;
79     }
80
81     ///////////////////////////////////////
82 // OTMKit Protocol
83 ///////////////////////////////////////
84
85     /**
86      * @see org.apache.ojb.otm.OTMKit#getTransactionFactory()
87      */
88     protected TransactionFactory getTransactionFactory()
89     {
90         return _txFactory;
91     }
92
93     /**
94      * @see org.apache.ojb.otm.OTMKit#getSwizzlingStrategy()
95      */
96     public Swizzling getSwizzlingStrategy()
97     {
98         return _swizzlingStrategy;
99     }
100
101
102     /**
103     * @see org.apache.ojb.otm.OTMKit#getLockWaitStrategy()
104     */
105     public LockWaitStrategy getLockWaitStrategy()
106     {
107         return _lockWaitStrategy;
108     }
109
110     /**
111      * @see org.apache.ojb.otm.OTMKit#getLockMap()
112      */
113     public LockMap getLockMap()
114     {
115         return _lockMap;
116     }
117
118     /**
119      * @see org.apache.ojb.otm.OTMKit#getCopyStrategy(Identity)
120      */
121     public ObjectCopyStrategy getCopyStrategy(Identity oid)
122     {
123         Class JavaDoc clazz = oid.getClass();
124
125         if (OjbCloneable.class.isAssignableFrom(clazz))
126         {
127             return _cloneableCopyStrategy;
128         }
129         else if (Serializable JavaDoc.class.isAssignableFrom(clazz))
130         {
131             return _defaultCopyStrategy;
132         }
133         else
134         {
135             return _noOpCopyStrategy;
136         }
137     }
138
139     /**
140      * Should OTM implicitely lock all objects that are reachable
141      * from the explicitely locked object? The updates to the locked
142      * objects are automatically stored to the database at the end
143      * of transaction.
144      **/
145     public boolean isImplicitLockingUsed()
146     {
147         return true;
148     }
149
150
151     /**
152      * Should OTM verify each inserted object for presence in the database?
153      **/
154     public boolean isInsertVerified()
155     {
156         return false;
157     }
158     
159     /**
160      * Should OTM perform INSERTs for the given object eagerly or during commit?
161      **/
162     public boolean isEagerInsert(Object JavaDoc obj)
163     {
164         return false;
165     }
166 }
167
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