com.freemedforms.openreact.engine.Configuration.java Source code

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Here is the source code for com.freemedforms.openreact.engine.Configuration.java

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/***************************************************************************
 *  The FreeMedForms project is a set of free, open source medical         *
 *  applications.                                                          *
 *  (C) 2008-2011 by Eric MAEKER, MD (France) <eric.maeker@free.fr>        *
 *  All rights reserved.                                                   *
 *                                                                         *
 *  This program is free software: you can redistribute it and/or modify   *
 *  it under the terms of the GNU General Public License as published by   *
 *  the Free Software Foundation, either version 3 of the License, or      *
 *  (at your option) any later version.                                    *
 *                                                                         *
 *  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 General Public License for more details.                           *
 *                                                                         *
 *  You should have received a copy of the GNU General Public License      *
 *  along with this program (COPYING.FREEMEDFORMS file).                   *
 *  If not, see <http://www.gnu.org/licenses/>.                            *
 ***************************************************************************/
/***************************************************************************
 *   OpenReact Web Portal                                                  *
 *   Main Developer : Jeff Buchbinder <jeff@freemedsoftware.org>           *
 *   Contributors :                                                        *
 *       NAME <MAIL@ADDRESS>                                               *
 ***************************************************************************/

package com.freemedforms.openreact.engine;

import java.beans.PropertyVetoException;
import java.io.File;
import java.sql.Connection;
import java.sql.SQLException;

import javax.servlet.ServletException;

import org.apache.commons.configuration.CompositeConfiguration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy;
import org.apache.log4j.Logger;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class Configuration {

    static final Logger logger = Logger.getLogger(Configuration.class);

    protected static CompositeConfiguration compositeConfiguration = null;

    protected static ComboPooledDataSource comboPooledDataSource = null;

    public static void loadConfiguration(String defaultConfig, String overrideConfig) {
        logger.trace("Entered loadConfiguration");
        if (compositeConfiguration == null) {
            logger.info("Configuration object not present, instantiating");
            compositeConfiguration = new CompositeConfiguration();

            PropertiesConfiguration defaults = null;
            try {
                logger.info("Attempting to create PropertiesConfiguration object for DEFAULT_CONFIG");
                defaults = new PropertiesConfiguration(defaultConfig);
                logger.info("Loading default configuration from " + defaultConfig);
                defaults.load();
            } catch (ConfigurationException e) {
                logger.error("Could not load default configuration from " + defaultConfig);
                logger.error(e);
            }
            if (overrideConfig != null) {
                PropertiesConfiguration overrides = null;
                try {
                    logger.info("Attempting to create PropertiesConfiguration object for OVERRIDE_CONFIG");
                    overrides = new PropertiesConfiguration();
                    logger.info("Setting file for OVERRIDE_CONFIG");
                    overrides.setFile(new File(overrideConfig));
                    logger.info("Setting reload strategy for OVERRIDE_CONFIG");
                    overrides.setReloadingStrategy(new FileChangedReloadingStrategy());
                    logger.info("Loading OVERRIDE_CONFIG");
                    overrides.load();
                } catch (ConfigurationException e) {
                    logger.error("Could not load overrides", e);
                } catch (Exception ex) {
                    logger.error(ex);
                }
                if (overrides != null) {
                    compositeConfiguration.addConfiguration(overrides);
                }
            }
            // Afterwards, add defaults so they're read second.
            compositeConfiguration.addConfiguration(defaults);
        }
    }

    public static CompositeConfiguration getConfiguration() {
        return compositeConfiguration;
    }

    public static void createDbPool() throws ServletException {
        String jdbcUrl = null;
        String jdbcDriver = null;
        System.out.println("Creating db connections");
        try {
            jdbcUrl = getConfiguration().getString("db.url");
            logger.debug("Found db.url string = " + jdbcUrl);
            jdbcDriver = getConfiguration().getString("db.driver");
            logger.debug("Found db.driver string = " + jdbcDriver);
        } catch (Exception ex) {
            logger.error("Could not get db.url", ex);
            throw new ServletException();
        }

        try {
            Class.forName(jdbcDriver).newInstance();
        } catch (Exception ex) {
            logger.error("Unable to load driver.", ex);
            throw new ServletException();
        }

        // Connection pool
        comboPooledDataSource = new ComboPooledDataSource();
        try {
            comboPooledDataSource.setDriverClass(jdbcDriver);
        } catch (PropertyVetoException e) {
            logger.error(e);
            throw new ServletException();
        }
        comboPooledDataSource.setJdbcUrl(jdbcUrl);
        comboPooledDataSource.setDataSourceName("jdbc/openreact");

        comboPooledDataSource.setMinPoolSize(getConfiguration().getInt("c3p0.minPoolSize"));
        comboPooledDataSource.setMaxPoolSize(getConfiguration().getInt("c3p0.maxPoolSize"));

        // Set settings from configuration file
        comboPooledDataSource.setMaxStatements(getConfiguration().getInt("c3p0.maxStatements"));
        comboPooledDataSource.setMaxIdleTime(getConfiguration().getInt("c3p0.maxIdleTime"));
    }

    /**
     * Get an unused database connection from the <ComboPooledDataSource> pool
     * of db connections.
     * 
     * @return
     */
    public static Connection getConnection() {
        try {
            return comboPooledDataSource.getConnection();
        } catch (SQLException e) {
            logger.error(e);
            return null;
        }
    }

}