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Java > Open Source Codes > org > springframework > jdbc > support > JdbcAccessor


1 /*
2  * Copyright 2002-2007 the original author or authors.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.springframework.jdbc.support;
18
19 import javax.sql.DataSource JavaDoc;
20
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23
24 import org.springframework.beans.factory.InitializingBean;
25
26 /**
27  * Base class for {@link org.springframework.jdbc.core.JdbcTemplate} and
28  * other JDBC-accessing DAO helpers, defining common properties such as
29  * DataSource and exception translator.
30  *
31  * <p>Not intended to be used directly.
32  * See {@link org.springframework.jdbc.core.JdbcTemplate}.
33  *
34  * @author Juergen Hoeller
35  * @since 28.11.2003
36  * @see org.springframework.jdbc.core.JdbcTemplate
37  */
38 public abstract class JdbcAccessor implements InitializingBean {
39
40     /** Logger available to subclasses */
41     protected final Log logger = LogFactory.getLog(getClass());
42
43     private DataSource JavaDoc dataSource;
44
45     private SQLExceptionTranslator exceptionTranslator;
46
47     private boolean lazyInit = true;
48
49
50     /**
51      * Set the JDBC DataSource to obtain connections from.
52      */
53     public void setDataSource(DataSource JavaDoc dataSource) {
54         this.dataSource = dataSource;
55     }
56
57     /**
58      * Return the DataSource used by this template.
59      */
60     public DataSource JavaDoc getDataSource() {
61         return this.dataSource;
62     }
63
64     /**
65      * Specify the database product name for the DataSource that this accessor uses.
66      * This allows to initialize a SQLErrorCodeSQLExceptionTranslator without
67      * obtaining a Connection from the DataSource to get the metadata.
68      * @param dbName the database product name that identifies the error codes entry
69      * @see SQLErrorCodeSQLExceptionTranslator#setDatabaseProductName
70      * @see java.sql.DatabaseMetaData#getDatabaseProductName()
71      */
72     public void setDatabaseProductName(String JavaDoc dbName) {
73         this.exceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dbName);
74     }
75
76     /**
77      * Set the exception translator for this instance.
78      * <p>If no custom translator is provided, a default
79      * {@link SQLErrorCodeSQLExceptionTranslator} is used
80      * which examines the SQLException's vendor-specific error code.
81      * @see org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator
82      * @see org.springframework.jdbc.support.SQLStateSQLExceptionTranslator
83      */
84     public void setExceptionTranslator(SQLExceptionTranslator exceptionTranslator) {
85         this.exceptionTranslator = exceptionTranslator;
86     }
87
88     /**
89      * Return the exception translator for this instance.
90      * <p>Creates a default {@link SQLErrorCodeSQLExceptionTranslator}
91      * for the specified DataSource if none set, or a
92      * {@link SQLStateSQLExceptionTranslator} in case of no DataSource.
93      * @see #getDataSource()
94      */
95     public synchronized SQLExceptionTranslator getExceptionTranslator() {
96         if (this.exceptionTranslator == null) {
97             DataSource JavaDoc dataSource = getDataSource();
98             if (dataSource != null) {
99                 this.exceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dataSource);
100             }
101             else {
102                 this.exceptionTranslator = new SQLStateSQLExceptionTranslator();
103             }
104         }
105         return this.exceptionTranslator;
106     }
107
108     /**
109      * Set whether to lazily initialize the SQLExceptionTranslator for this accessor,
110      * on first encounter of a SQLException. Default is "true"; can be switched to
111      * "false" for initialization on startup.
112      * <p>Early initialization just applies if <code>afterPropertiesSet()</code> is called.
113      * @see #getExceptionTranslator()
114      * @see #afterPropertiesSet()
115      */
116     public void setLazyInit(boolean lazyInit) {
117         this.lazyInit = lazyInit;
118     }
119
120     /**
121      * Return whether to lazily initialize the SQLExceptionTranslator for this accessor.
122      * @see #getExceptionTranslator()
123      */
124     public boolean isLazyInit() {
125         return this.lazyInit;
126     }
127
128     /**
129      * Eagerly initialize the exception translator, if demanded,
130      * creating a default one for the specified DataSource if none set.
131      */
132     public void afterPropertiesSet() {
133         if (getDataSource() == null) {
134             throw new IllegalArgumentException JavaDoc("Property 'dataSource' is required");
135         }
136         if (!isLazyInit()) {
137             getExceptionTranslator();
138         }
139     }
140
141 }
142
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