KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > derby > impl > store > raw > data > ContainerActionOnCommit


1 /*
2
3    Derby - Class org.apache.derby.impl.store.raw.data.ContainerActionOnCommit
4
5    Licensed to the Apache Software Foundation (ASF) under one or more
6    contributor license agreements. See the NOTICE file distributed with
7    this work for additional information regarding copyright ownership.
8    The ASF licenses this file to you under the Apache License, Version 2.0
9    (the "License"); you may not use this file except in compliance with
10    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, software
15    distributed under the License is distributed on an "AS IS" BASIS,
16    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17    See the License for the specific language governing permissions and
18    limitations under the License.
19
20  */
21
22 package org.apache.derby.impl.store.raw.data;
23
24 import org.apache.derby.iapi.store.raw.ContainerKey;
25
26 import java.util.Observer JavaDoc;
27
28 /**
29     An Observer that can be attached to a transaction to
30     implement some action when the transaction
31     commits or rollsback in some way.
32 */
33
34 abstract class ContainerActionOnCommit implements Observer JavaDoc {
35
36     protected ContainerKey identity;
37
38     protected ContainerActionOnCommit(ContainerKey identity) {
39
40         this.identity = identity;
41     }
42
43     public int hashCode() {
44         return identity.hashCode();
45     }
46
47     /**
48         An equals method that returns true if the other obejct
49         is a sub-class of this, and the container identities
50         are equal *and* it is the same class as this.
51         <BR>
52         This allows mutiple additions of value equality
53         obejcts to the observer list while only retaining one.
54     */
55     public boolean equals(Object JavaDoc other) {
56         if (other instanceof ContainerActionOnCommit) {
57             if (!identity.equals(((ContainerActionOnCommit) other).identity))
58                 return false;
59
60             // the class of the types must match as well
61 return getClass().equals(other.getClass());
62         }
63         return false;
64     }
65 }
66
Popular Tags