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Java > Open Source Codes > com > lutris > appserver > server > sessionEnhydra > persistent > KeyExistsQuery


1
2 /*
3  * Enhydra Java Application Server Project
4  *
5  * The contents of this file are subject to the Enhydra Public License
6  * Version 1.1 (the "License"); you may not use this file except in
7  * compliance with the License. You may obtain a copy of the License on
8  * the Enhydra web site ( http://www.enhydra.org/ ).
9  *
10  * Software distributed under the License is distributed on an "AS IS"
11  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
12  * the License for the specific terms governing rights and limitations
13  * under the License.
14  *
15  * The Initial Developer of the Enhydra Application Server is Lutris
16  * Technologies, Inc. The Enhydra Application Server and portions created
17  * by Lutris Technologies, Inc. are Copyright Lutris Technologies, Inc.
18  * All Rights Reserved.
19  *
20  * Contributor(s):
21  *
22  * $Id: KeyExistsQuery.java,v 1.2 2005/03/24 10:51:20 slobodan Exp $
23  */
24
25 package com.lutris.appserver.server.sessionEnhydra.persistent;
26
27 import java.sql.PreparedStatement JavaDoc;
28 import java.sql.ResultSet JavaDoc;
29 import java.sql.SQLException JavaDoc;
30
31 import com.lutris.appserver.server.sql.DBConnection;
32 import com.lutris.appserver.server.sql.Query;
33
34 /**
35  * Performs a query to determine if a session key exists.
36  *
37  * @version $Revision: 1.2 $
38  * @author Kyle Clark
39  */
40 class KeyExistsQuery implements Query {
41
42     private String JavaDoc sessionKey;
43
44     /**
45      * @param sessionKey
46      * the key for the session that should be retrieved.
47      */
48     KeyExistsQuery(String JavaDoc sessionKey) {
49         this.sessionKey = sessionKey;
50     }
51
52     /**
53      * Method to query the existence of the key.
54      *
55      * @param conn Handle to database connection.
56      * @exception java.sql.SQLException If a database access error occurs.
57      */
58     public ResultSet JavaDoc executeQuery(DBConnection conn)
59         throws SQLException JavaDoc {
60         String JavaDoc sql = "select sessionKey from "
61             + PersistentSessionHome.dbTableName
62             + " where sessionKey = ?";
63         PreparedStatement JavaDoc stmt = conn.prepareStatement(sql);
64         stmt.setString(1, sessionKey);
65         return conn.executeQuery(stmt, sql);
66     }
67
68     /**
69      * Returns Boolean(true) if the key exists. Boolean(false) otherwise.
70      *
71      * @param rs
72      * result set from which the next object will be instantiated.
73      * @return Boolean
74      * indicating if the key exists.
75      * @exception SQLException
76      * if a database access error occurs.
77      */
78     public Object JavaDoc next(ResultSet JavaDoc rs) throws SQLException JavaDoc {
79         if (rs.next()) {
80             return new Boolean JavaDoc(true);
81         } else {
82             return new Boolean JavaDoc(false);
83         }
84     }
85
86 }
87
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