de.xirp.db.XConnectionProvider.java Source code

Introduction

Here is the source code for de.xirp.db.XConnectionProvider.java

Source

/** 
 * ============================================================================
 * Xirp 2: eXtendable interface for robotic purposes.
 * ============================================================================
 * 
 * Copyright (C) 2005-2007, by Authors and Contributors listed in CREDITS.txt
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at:
 *
 *             http://www.opensource.org/licenses/cpl1.0.php
 *
 * ----------------------------
 * XConnectionProvider.java
 * ----------------------------
 *
 * Original Author:  Matthias Gernand [matthias.gernand AT gmx.de]
 * Contributor(s):   
 *
 * Changes
 * -------
 * 23.03.2007:      Created by Matthias Gernand.
 */
package de.xirp.db;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.commons.dbcp.DriverManagerConnectionFactory;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.PoolingDataSource;
import org.apache.commons.pool.impl.GenericObjectPool;
import org.hibernate.HibernateException;
import org.hibernate.connection.ConnectionProvider;

import de.xirp.util.I18n;

/**
 * This class is a database connection pool implementation using the
 * Apache Commons Pool and DBCP APIs. <br>
 * <br>
 * It implements the
 * {@link org.hibernate.connection.ConnectionProvider} interface from
 * the Hibernate API. So the connection pool can provide its
 * connections to Hibernate.
 * 
 * @author Matthias Gernand
 * @see org.apache.commons.dbcp.PoolingDataSource
 * @see org.apache.commons.pool.impl.GenericObjectPool
 * @see org.hibernate.connection.ConnectionProvider
 */
public class XConnectionProvider implements ConnectionProvider {

    private static final int MIN_IDLE = 5;
    private static final int MAX_ACTIVE = 10;
    private static final int EVICTION_TIME = 500;

    private static DataSource ds;
    private static GenericObjectPool connectionPool;
    private static DriverManagerConnectionFactory connectionFactory;
    @SuppressWarnings("unused")
    private static PoolableConnectionFactory poolableConnectionFactory;
    private static PoolingDataSource dataSource;

    /**
     * The connection pool is closed by this method.
     * 
     * @throws HibernateException
     *             if an exception occurs while closing the pool.
     * @see org.hibernate.connection.ConnectionProvider#close()
     * @see org.apache.commons.pool.impl.GenericObjectPool
     */
    public void close() throws HibernateException {
        try {
            connectionPool.close();
        } catch (Exception e) {
            throw new HibernateException(e);
        }
    }

    /**
     * The given {@link java.sql.Connection}> is closed.
     * 
     * @throws SQLException
     *             if an exception occurs while closing the
     *             connection.
     * @see org.hibernate.connection.ConnectionProvider#closeConnection(java.sql.Connection)
     * @see java.sql.Connection
     */
    public void closeConnection(Connection conn) throws SQLException {
        conn.close();
    }

    /**
     * The given {@link java.util.Properties} are used to configure
     * the connection pool. The pool is initialized.
     * 
     * @see org.hibernate.connection.ConnectionProvider#configure(java.util.Properties)
     */
    public void configure(Properties props) throws HibernateException {
        initPool(props.getProperty("hibernate.connection.url"), //$NON-NLS-1$
                props.getProperty("hibernate.connection.username"), //$NON-NLS-1$
                props.getProperty("hibernate.connection.password")); //$NON-NLS-1$
    }

    /**
     * This methos initializes the connection pool using the given
     * URL, user name and password.
     * 
     * @param url
     *            The db URL.
     * @param user
     *            The db user.
     * @param password
     *            The users password.
     */
    private void initPool(String url, String user, String password) {

        connectionPool = new GenericObjectPool();
        connectionFactory = new DriverManagerConnectionFactory(url, user, password);
        poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory, connectionPool, null, null,
                false, true);
        dataSource = new PoolingDataSource(connectionPool);

        dataSource.setAccessToUnderlyingConnectionAllowed(false);

        connectionPool.setMaxActive(MAX_ACTIVE);
        connectionPool.setWhenExhaustedAction(GenericObjectPool.WHEN_EXHAUSTED_GROW);
        connectionPool.setMinIdle(MIN_IDLE);
        connectionPool.setTimeBetweenEvictionRunsMillis(EVICTION_TIME);
        connectionPool.setTestOnBorrow(true);
        connectionPool.setTestWhileIdle(false);
        connectionPool.setTestOnReturn(false);

        ds = dataSource;
    }

    /**
     * Returns a {@link java.sql.Connection} from the pool.
     * 
     * @throws SQLException
     *             if something went wrong getting a connection.
     * @see org.hibernate.connection.ConnectionProvider#getConnection()
     * @see java.sql.Connection
     */
    public Connection getConnection() throws SQLException {
        if (ds != null) {
            Connection c = ds.getConnection();
            /*
             * logClass.debug("Active: " +
             * connectionPool.getNumActive( ) + "\n");
             * logClass.debug("Idle: " + connectionPool.getNumIdle( ) +
             * "\n");
             */
            return c;
        } else {
            throw new SQLException(I18n.getString("XConnectionProvider.exception.datasourceNotAvailable")); //$NON-NLS-1$
        }
    }

    /**
     * This implementation does not support aggressive release.
     * 
     * @see org.hibernate.connection.ConnectionProvider#supportsAggressiveRelease()
     */
    public boolean supportsAggressiveRelease() {
        return false;
    }

    /**
     * Returns the number of idle connection in the pool.
     * 
     * @return The number of idle connections.
     * @see org.apache.commons.pool.impl.GenericObjectPool#getNumIdle()
     */
    protected int getNumIdle() {
        return connectionPool.getNumIdle();
    }

    /**
     * Returns the number of active connections in the pool.
     * 
     * @return The number of active connections.
     * @see org.apache.commons.pool.impl.GenericObjectPool#getNumActive()
     */
    protected int getNumActive() {
        return connectionPool.getNumActive();
    }
}