org.springframework.jdbc.core.support.JdbcDaoSupport Maven / Gradle / Ivy
/*
* Copyright 2002-2022 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.jdbc.core.support;
import java.sql.Connection;
import javax.sql.DataSource;
import org.springframework.dao.support.DaoSupport;
import org.springframework.jdbc.CannotGetJdbcConnectionException;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.jdbc.support.SQLExceptionTranslator;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
/**
* Convenient superclass for JDBC-based data access objects.
*
* Requires a {@link javax.sql.DataSource} to be set, providing a
* {@link org.springframework.jdbc.core.JdbcTemplate} based on it to
* subclasses through the {@link #getJdbcTemplate()} method.
*
*
This base class is mainly intended for JdbcTemplate usage but can
* also be used when working with a Connection directly or when using
* {@code org.springframework.jdbc.object} operation objects.
*
* @author Juergen Hoeller
* @since 28.07.2003
* @see #setDataSource
* @see #getJdbcTemplate
* @see org.springframework.jdbc.core.JdbcTemplate
*/
public abstract class JdbcDaoSupport extends DaoSupport {
@Nullable
private JdbcTemplate jdbcTemplate;
/**
* Set the JDBC DataSource to be used by this DAO.
*/
public final void setDataSource(DataSource dataSource) {
if (this.jdbcTemplate == null || dataSource != this.jdbcTemplate.getDataSource()) {
this.jdbcTemplate = createJdbcTemplate(dataSource);
initTemplateConfig();
}
}
/**
* Create a JdbcTemplate for the given DataSource.
* Only invoked if populating the DAO with a DataSource reference!
*
Can be overridden in subclasses to provide a JdbcTemplate instance
* with different configuration, or a custom JdbcTemplate subclass.
* @param dataSource the JDBC DataSource to create a JdbcTemplate for
* @return the new JdbcTemplate instance
* @see #setDataSource
*/
protected JdbcTemplate createJdbcTemplate(DataSource dataSource) {
return new JdbcTemplate(dataSource);
}
/**
* Return the JDBC DataSource used by this DAO.
*/
@Nullable
public final DataSource getDataSource() {
return (this.jdbcTemplate != null ? this.jdbcTemplate.getDataSource() : null);
}
/**
* Set the JdbcTemplate for this DAO explicitly,
* as an alternative to specifying a DataSource.
*/
public final void setJdbcTemplate(@Nullable JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
initTemplateConfig();
}
/**
* Return the JdbcTemplate for this DAO,
* pre-initialized with the DataSource or set explicitly.
*/
@Nullable
public final JdbcTemplate getJdbcTemplate() {
return this.jdbcTemplate;
}
/**
* Initialize the template-based configuration of this DAO.
* Called after a new JdbcTemplate has been set, either directly
* or through a DataSource.
*
This implementation is empty. Subclasses may override this
* to configure further objects based on the JdbcTemplate.
* @see #getJdbcTemplate()
*/
protected void initTemplateConfig() {
}
@Override
protected void checkDaoConfig() {
if (this.jdbcTemplate == null) {
throw new IllegalArgumentException("'dataSource' or 'jdbcTemplate' is required");
}
}
/**
* Return the SQLExceptionTranslator of this DAO's JdbcTemplate,
* for translating SQLExceptions in custom JDBC access code.
* @see org.springframework.jdbc.core.JdbcTemplate#getExceptionTranslator()
*/
protected final SQLExceptionTranslator getExceptionTranslator() {
JdbcTemplate jdbcTemplate = getJdbcTemplate();
Assert.state(jdbcTemplate != null, "No JdbcTemplate set");
return jdbcTemplate.getExceptionTranslator();
}
/**
* Get a JDBC Connection, either from the current transaction or a new one.
* @return the JDBC Connection
* @throws CannotGetJdbcConnectionException if the attempt to get a Connection failed
* @see org.springframework.jdbc.datasource.DataSourceUtils#getConnection(javax.sql.DataSource)
*/
protected final Connection getConnection() throws CannotGetJdbcConnectionException {
DataSource dataSource = getDataSource();
Assert.state(dataSource != null, "No DataSource set");
return DataSourceUtils.getConnection(dataSource);
}
/**
* Close the given JDBC Connection, created via this DAO's DataSource,
* if it isn't bound to the thread.
* @param con the Connection to close
* @see org.springframework.jdbc.datasource.DataSourceUtils#releaseConnection
*/
protected final void releaseConnection(Connection con) {
DataSourceUtils.releaseConnection(con, getDataSource());
}
}