001/*
002 * Copyright 2002-2018 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.jdbc.support;
018
019import javax.sql.DataSource;
020
021import org.apache.commons.logging.Log;
022import org.apache.commons.logging.LogFactory;
023
024import org.springframework.beans.factory.InitializingBean;
025
026/**
027 * Base class for {@link org.springframework.jdbc.core.JdbcTemplate} and
028 * other JDBC-accessing DAO helpers, defining common properties such as
029 * DataSource and exception translator.
030 *
031 * <p>Not intended to be used directly.
032 * See {@link org.springframework.jdbc.core.JdbcTemplate}.
033 *
034 * @author Juergen Hoeller
035 * @since 28.11.2003
036 * @see org.springframework.jdbc.core.JdbcTemplate
037 */
038public abstract class JdbcAccessor implements InitializingBean {
039
040        /** Logger available to subclasses */
041        protected final Log logger = LogFactory.getLog(getClass());
042
043        private DataSource dataSource;
044
045        private volatile SQLExceptionTranslator exceptionTranslator;
046
047        private boolean lazyInit = true;
048
049
050        /**
051         * Set the JDBC DataSource to obtain connections from.
052         */
053        public void setDataSource(DataSource dataSource) {
054                this.dataSource = dataSource;
055        }
056
057        /**
058         * Return the DataSource used by this template.
059         */
060        public DataSource getDataSource() {
061                return this.dataSource;
062        }
063
064        /**
065         * Specify the database product name for the DataSource that this accessor uses.
066         * This allows to initialize a SQLErrorCodeSQLExceptionTranslator without
067         * obtaining a Connection from the DataSource to get the meta-data.
068         * @param dbName the database product name that identifies the error codes entry
069         * @see SQLErrorCodeSQLExceptionTranslator#setDatabaseProductName
070         * @see java.sql.DatabaseMetaData#getDatabaseProductName()
071         */
072        public void setDatabaseProductName(String dbName) {
073                this.exceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dbName);
074        }
075
076        /**
077         * Set the exception translator for this instance.
078         * <p>If no custom translator is provided, a default
079         * {@link SQLErrorCodeSQLExceptionTranslator} is used
080         * which examines the SQLException's vendor-specific error code.
081         * @see org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator
082         * @see org.springframework.jdbc.support.SQLStateSQLExceptionTranslator
083         */
084        public void setExceptionTranslator(SQLExceptionTranslator exceptionTranslator) {
085                this.exceptionTranslator = exceptionTranslator;
086        }
087
088        /**
089         * Return the exception translator for this instance.
090         * <p>Creates a default {@link SQLErrorCodeSQLExceptionTranslator}
091         * for the specified DataSource if none set, or a
092         * {@link SQLStateSQLExceptionTranslator} in case of no DataSource.
093         * @see #getDataSource()
094         */
095        public SQLExceptionTranslator getExceptionTranslator() {
096                SQLExceptionTranslator exceptionTranslator = this.exceptionTranslator;
097                if (exceptionTranslator != null) {
098                        return exceptionTranslator;
099                }
100                synchronized (this) {
101                        exceptionTranslator = this.exceptionTranslator;
102                        if (exceptionTranslator == null) {
103                                DataSource dataSource = getDataSource();
104                                if (dataSource != null) {
105                                        exceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dataSource);
106                                }
107                                else {
108                                        exceptionTranslator = new SQLStateSQLExceptionTranslator();
109                                }
110                                this.exceptionTranslator = exceptionTranslator;
111                        }
112                        return exceptionTranslator;
113                }
114        }
115
116        /**
117         * Set whether to lazily initialize the SQLExceptionTranslator for this accessor,
118         * on first encounter of a SQLException. Default is "true"; can be switched to
119         * "false" for initialization on startup.
120         * <p>Early initialization just applies if {@code afterPropertiesSet()} is called.
121         * @see #getExceptionTranslator()
122         * @see #afterPropertiesSet()
123         */
124        public void setLazyInit(boolean lazyInit) {
125                this.lazyInit = lazyInit;
126        }
127
128        /**
129         * Return whether to lazily initialize the SQLExceptionTranslator for this accessor.
130         * @see #getExceptionTranslator()
131         */
132        public boolean isLazyInit() {
133                return this.lazyInit;
134        }
135
136        /**
137         * Eagerly initialize the exception translator, if demanded,
138         * creating a default one for the specified DataSource if none set.
139         */
140        @Override
141        public void afterPropertiesSet() {
142                if (getDataSource() == null) {
143                        throw new IllegalArgumentException("Property 'dataSource' is required");
144                }
145                if (!isLazyInit()) {
146                        getExceptionTranslator();
147                }
148        }
149
150}