Technical blog

Properties props = new Properties();
 
//this line is the killer: delegates the ConnectionProvider to our custom implementation
//look at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider()
props.put(Environment.CONNECTION_PROVIDER, MyConnectionProvider.class
.getName());

 
package com.swayam.teneo.config;
 
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
 
import javax.sql.DataSource;
 
import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.dbcp.DriverManagerConnectionFactory;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.PoolingDataSource;
import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.impl.GenericObjectPool;
import org.hibernate.HibernateException;
import org.hibernate.cfg.Environment;
import org.hibernate.connection.ConnectionProvider;
 
/**
 * 
 * @author paawak
 */
public class MyConnectionProvider implements ConnectionProvider {
 
    private DataSource ds;
 
    public MyConnectionProvider() {
 
    }
 
    public void close() throws HibernateException {
        // TODO Auto-generated method stub
 
    }
 
    public void closeConnection(Connection conn) throws SQLException {
        conn.close();
    }
 
    public void configure(Properties props) throws HibernateException {
 
        String jdbcDriver = (String) props.get(Environment.DRIVER);
 
        if (jdbcDriver == null) {
            throw new HibernateException(
                    "Please specify the JDBC driver with the key `Environment.DRIVER`");
        }
 
        // load the driver
        try {
            Class.forName(jdbcDriver);
        } catch (ClassNotFoundException e) {
            throw new HibernateException(e);
        }
 
        String connectURI = (String) props.get(Environment.URL);
 
        if (connectURI == null) {
            throw new HibernateException(
                    "Please specify the connection URL with the key `Environment.URL`");
        }
 
        ds = setupDataSource(connectURI);
    }
 
    public Connection getConnection() throws SQLException {
        return ds.getConnection();
    }
 
    public boolean supportsAggressiveRelease() {
        // TODO Auto-generated method stub
        return false;
    }
 
    /**
     * refer to DBCP ManualPoolingDataSourceExample:
     * 
     * 
     * http://svn.apache.org/viewvc/commons/proper/dbcp/trunk/doc/ManualPoolingDataSourceExample.java?view=markup
     * 
     * 
     * This is made static for de-coupling
     * 
     */
    private static DataSource setupDataSource(String connectURI) {
        //
        // First, we'll need a ObjectPool that serves as the
        // actual pool of connections.
        //
        // We'll use a GenericObjectPool instance, although
        // any ObjectPool implementation will suffice.
        //
        ObjectPool connectionPool = new GenericObjectPool(null);
 
        //
        // Next, we'll create a ConnectionFactory that the
        // pool will use to create Connections.
        // We'll use the DriverManagerConnectionFactory,
        // using the connect string passed in the command line
        // arguments.
        //
        ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(
                connectURI, null);
 
        //
        // Now we'll create the PoolableConnectionFactory, which wraps
        // the "real" Connections created by the ConnectionFactory with
        // the classes that implement the pooling functionality.
        //
        @SuppressWarnings("unused")
        PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(
                connectionFactory, connectionPool, null, null, false, true);
 
        //
        // Finally, we create the PoolingDriver itself,
        // passing in the object pool we created.
        //
        PoolingDataSource dataSource = new PoolingDataSource(connectionPool);
 
        return dataSource;
    }
 
}