com.jn.sqlhelper.datasource.driver.DriverManagerDataSource Maven / Gradle / Ivy
/*
* Copyright 2020 the original author or authors.
*
* Licensed under the LGPL, Version 3.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.gnu.org/licenses/lgpl-3.0.html
*
* 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 com.jn.sqlhelper.datasource.driver;
import com.jn.langx.util.ClassLoaders;
import com.jn.langx.util.Preconditions;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
/**
* Simple implementation of the standard JDBC {@link javax.sql.DataSource} interface,
* configuring the plain old JDBC {@link java.sql.DriverManager} via bean properties, and
* returning a new {@link java.sql.Connection} from every {@code getConnection} call.
*
* NOTE: This class is not an actual connection pool; it does not actually
* pool Connections. It just serves as simple replacement for a full-blown
* connection pool, implementing the same standard interface, but creating new
* Connections on every call.
*
*
Useful for test or standalone environments outside of a J2EE container, either
* as a DataSource bean in a corresponding ApplicationContext or in conjunction with
* a simple JNDI environment. Pool-assuming {@code Connection.close()} calls will
* simply close the Connection, so any DataSource-aware persistence code should work.
*
*
NOTE: Within special class loading environments such as OSGi, this class
* is effectively superseded by {@link SimpleDriverDataSource} due to general class
* loading issues with the JDBC DriverManager that be resolved through direct Driver
* usage (which is exactly what SimpleDriverDataSource does).
*
*
In a J2EE container, it is recommended to use a JNDI DataSource provided by
* the container. Such a DataSource can be exposed as a DataSource bean in a Spring
* ApplicationContext via JndiObjectFactoryBean,
* for seamless switching to and from a local DataSource bean like this class.
* For tests, you can then either set up a mock JNDI environment through Spring's
* org.springframework.mock.jndi.SimpleNamingContextBuilder, or switch the
* bean definition to a local DataSource (which is simpler and thus recommended).
*
*
If you need a "real" connection pool outside of a J2EE container, consider
* Apache Commons DBCP
* or C3P0.
* Commons DBCP's BasicDataSource and C3P0's ComboPooledDataSource are full
* connection pool beans, supporting the same basic properties as this class
* plus specific settings (such as minimal/maximal pool size etc).
*
* @see SimpleDriverDataSource
* @since 3.4.0
*/
public class DriverManagerDataSource extends AbstractDriverBasedDataSource {
/**
* Constructor for bean-style configuration.
*/
public DriverManagerDataSource() {
}
/**
* Create a new DriverManagerDataSource with the given JDBC URL,
* not specifying a username or password for JDBC access.
* @param url the JDBC URL to use for accessing the DriverManager
* @see java.sql.DriverManager#getConnection(String)
*/
public DriverManagerDataSource(String url) {
setUrl(url);
}
/**
* Create a new DriverManagerDataSource with the given standard
* DriverManager parameters.
* @param url the JDBC URL to use for accessing the DriverManager
* @param username the JDBC username to use for accessing the DriverManager
* @param password the JDBC password to use for accessing the DriverManager
* @see java.sql.DriverManager#getConnection(String, String, String)
*/
public DriverManagerDataSource(String url, String username, String password) {
setUrl(url);
setUsername(username);
setPassword(password);
}
/**
* Create a new DriverManagerDataSource with the given JDBC URL,
* not specifying a username or password for JDBC access.
* @param url the JDBC URL to use for accessing the DriverManager
* @param conProps JDBC connection properties
* @see java.sql.DriverManager#getConnection(String)
*/
public DriverManagerDataSource(String url, Properties conProps) {
setUrl(url);
setConnectionProperties(conProps);
}
/**
* Set the JDBC driver class name. This driver will get initialized
* on startup, registering itself with the JDK's DriverManager.
*
NOTE: DriverManagerDataSource is primarily intended for accessing
* pre-registered JDBC drivers. If you need to register a new driver,
* consider using {@link SimpleDriverDataSource} instead. Alternatively, consider
* initializing the JDBC driver yourself before instantiating this DataSource.
* The "driverClassName" property is mainly preserved for backwards compatibility,
* as well as for migrating between Commons DBCP and this DataSource.
* @see java.sql.DriverManager#registerDriver(java.sql.Driver)
* @see SimpleDriverDataSource
*/
public void setDriverClassName(String driverClassName) {
Preconditions.checkNotEmpty(driverClassName, "Property 'driverClassName' must not be empty");
String driverClassNameToUse = driverClassName.trim();
try {
Class.forName(driverClassNameToUse, true, ClassLoaders.getDefaultClassLoader());
}
catch (ClassNotFoundException ex) {
throw new IllegalStateException("Could not load JDBC driver class [" + driverClassNameToUse + "]", ex);
}
if (logger.isInfoEnabled()) {
logger.info("Loaded JDBC driver: " + driverClassNameToUse);
}
}
@Override
protected Connection getConnectionFromDriver(Properties props) throws SQLException {
String url = getUrl();
if (logger.isDebugEnabled()) {
logger.debug("Creating new JDBC DriverManager Connection to [" + url + "]");
}
return getConnectionFromDriverManager(url, props);
}
/**
* Getting a Connection using the nasty static from DriverManager is extracted
* into a protected method to allow for easy unit testing.
* @see java.sql.DriverManager#getConnection(String, java.util.Properties)
*/
protected Connection getConnectionFromDriverManager(String url, Properties props) throws SQLException {
return DriverManager.getConnection(url, props);
}
}