Hibernate example source code file (DriverManagerConnectionProviderImpl.java)

This example Hibernate source code file (DriverManagerConnectionProviderImpl.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

arraylist, classnotfoundexception, connection, connection, hibernateexception, jdbc, jdbc, override, sql, sqlexception, sqlexception, string, string, suppresswarnings, t, util

The Hibernate DriverManagerConnectionProviderImpl.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.service.jdbc.connections.internal;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Map;
import java.util.Properties;
import org.hibernate.HibernateException;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.cfg.Environment;
import org.hibernate.internal.util.ReflectHelper;
import org.hibernate.internal.util.config.ConfigurationHelper;
import org.hibernate.service.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.service.spi.Configurable;
import org.hibernate.service.spi.Stoppable;
import org.hibernate.service.UnknownUnwrapTypeException;
import org.jboss.logging.Logger;

/**
 * A connection provider that uses the {@link java.sql.DriverManager} directly to open connections and provides
 * a very rudimentary connection pool.
 * <p/>
 * IMPL NOTE : not intended for production use!
 *
 * @author Gavin King
 * @author Steve Ebersole
 */
@SuppressWarnings( {"UnnecessaryUnboxing"})
public class DriverManagerConnectionProviderImpl implements ConnectionProvider, Configurable, Stoppable {

    private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class,
                                                                       DriverManagerConnectionProviderImpl.class.getName());

	private String url;
	private Properties connectionProps;
	private Integer isolation;
	private int poolSize;
	private boolean autocommit;

	private final ArrayList<Connection> pool = new ArrayList();
	private int checkedOut = 0;

	private boolean stopped;

	@Override
	public boolean isUnwrappableAs(Class unwrapType) {
		return ConnectionProvider.class.equals( unwrapType ) ||
				DriverManagerConnectionProviderImpl.class.isAssignableFrom( unwrapType );
	}

	@Override
	@SuppressWarnings( {"unchecked"})
	public <T> T unwrap(Class unwrapType) {
		if ( ConnectionProvider.class.equals( unwrapType ) ||
				DriverManagerConnectionProviderImpl.class.isAssignableFrom( unwrapType ) ) {
			return (T) this;
		}
		else {
			throw new UnknownUnwrapTypeException( unwrapType );
		}
	}

	public void configure(Map configurationValues) {
        LOG.usingHibernateBuiltInConnectionPool();

		String driverClassName = (String) configurationValues.get( Environment.DRIVER );
        if (driverClassName == null) LOG.jdbcDriverNotSpecified(Environment.DRIVER);
		else {
			try {
				// trying via forName() first to be as close to DriverManager's semantics
				Class.forName( driverClassName );
			}
			catch ( ClassNotFoundException cnfe ) {
				try {
					ReflectHelper.classForName( driverClassName );
				}
				catch ( ClassNotFoundException e ) {
					throw new HibernateException( "Specified JDBC Driver " + driverClassName + " class not found", e );
				}
			}
		}

		poolSize = ConfigurationHelper.getInt( Environment.POOL_SIZE, configurationValues, 20 ); // default pool size 20
        LOG.hibernateConnectionPoolSize(poolSize);

		autocommit = ConfigurationHelper.getBoolean( Environment.AUTOCOMMIT, configurationValues );
        LOG.autoCommitMode( autocommit );

		isolation = ConfigurationHelper.getInteger( Environment.ISOLATION, configurationValues );
        if (isolation != null) LOG.jdbcIsolationLevel(Environment.isolationLevelToString(isolation.intValue()));

		url = (String) configurationValues.get( Environment.URL );
		if ( url == null ) {
            String msg = LOG.jdbcUrlNotSpecified(Environment.URL);
            LOG.error(msg);
			throw new HibernateException( msg );
		}

		connectionProps = ConnectionProviderInitiator.getConnectionProperties( configurationValues );

        LOG.usingDriver(driverClassName, url);
		// if debug level is enabled, then log the password, otherwise mask it
        if (LOG.isDebugEnabled()) LOG.connectionProperties(connectionProps);
        else LOG.connectionProperties(ConfigurationHelper.maskOut(connectionProps, "password"));
	}

	public void stop() {
        LOG.cleaningUpConnectionPool(url);

		for ( Connection connection : pool ) {
			try {
				connection.close();
			}
			catch (SQLException sqle) {
                LOG.unableToClosePooledConnection(sqle);
			}
		}
		pool.clear();
		stopped = true;
	}

	public Connection getConnection() throws SQLException {
        LOG.trace("Total checked-out connections: " + checkedOut);

		// essentially, if we have available connections in the pool, use one...
		synchronized (pool) {
			if ( !pool.isEmpty() ) {
				int last = pool.size() - 1;
                if (LOG.isTraceEnabled()) {
                    LOG.trace("Using pooled JDBC connection, pool size: " + last);
					checkedOut++;
				}
				Connection pooled = pool.remove(last);
				if ( isolation != null ) {
					pooled.setTransactionIsolation( isolation.intValue() );
				}
				if ( pooled.getAutoCommit() != autocommit ) {
					pooled.setAutoCommit( autocommit );
				}
				return pooled;
			}
		}

		// otherwise we open a new connection...

        LOG.debugf("Opening new JDBC connection");
		Connection conn = DriverManager.getConnection( url, connectionProps );
		if ( isolation != null ) {
			conn.setTransactionIsolation( isolation.intValue() );
		}
		if ( conn.getAutoCommit() != autocommit ) {
			conn.setAutoCommit(autocommit);
		}

        LOG.debugf("Created connection to: %s, Isolation Level: %s", url, conn.getTransactionIsolation());

		checkedOut++;

		return conn;
	}

	public void closeConnection(Connection conn) throws SQLException {
		checkedOut--;

		// add to the pool if the max size is not yet reached.
		synchronized (pool) {
			int currentSize = pool.size();
			if ( currentSize < poolSize ) {
                LOG.trace("Returning connection to pool, pool size: " + (currentSize + 1));
				pool.add(conn);
				return;
			}
		}

        LOG.debugf("Closing JDBC connection");
		conn.close();
	}

	@Override
    protected void finalize() throws Throwable {
		if ( !stopped ) {
			stop();
		}
		super.finalize();
	}

	public boolean supportsAggressiveRelease() {
		return false;
	}
}