dbconnectionmanager.java

定时器开源项目, 相对于 jcrontab, Quartz 算是更完整的一个项目, 随著开发的版本上来, 他已经脱离只是写在程序里面的计时器, 在指定的时间或区间, 处理所指定的事件. 也加入了 se

/*
 * Copyright James House (c) 2001-2004
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: 1.
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer. 2. Redistributions in
 * binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other
 * materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * 
 * This product includes software developed by the Apache Software Foundation
 * (http://www.apache.org/)
 */
package org.quartz.utils;

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

/**
 * <p>
 * Manages a collection of ConnectionProviders, and provides transparent access
 * to their connections.
 * </p>
 * 
 * @see ConnectionProvider
 * @see PoolingConnectionProvider
 * @see JNDIConnectionProvider
 * @see org.quartz.utils.weblogic.WeblogicConnectionProvider
 * 
 * @author James House
 * @author Sharada Jambula
 * @author Mohammad Rezaei
 */
public class DBConnectionManager {

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Constants.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    public static final String DB_PROPS_PREFIX = "org.quartz.db.";

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Data members.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    private static DBConnectionManager instance = new DBConnectionManager();

    private HashMap providers = new HashMap();

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Constructors.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    /**
     * <p>
     * Private constructor
     * </p>
     *  
     */
    private DBConnectionManager() {
    }

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Interface.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    public void addConnectionProvider(String dataSourceName,
            ConnectionProvider provider) {
        this.providers.put(dataSourceName, provider);
    }

    /**
     * Get a database connection from the DataSource with the given name.
     * 
     * @return a database connection
     * @exception SQLException
     *              if an error occurs, or there is no DataSource with the
     *              given name.
     */
    public Connection getConnection(String dsName) throws SQLException {
        ConnectionProvider provider = (ConnectionProvider) providers
                .get(dsName);
        if (provider == null)
                throw new SQLException("There is no DataSource named '"
                        + dsName + "'");

        return provider.getConnection();
    }

    /**
     * Get the class instance.
     * 
     * @return an instance of this class
     */
    public static DBConnectionManager getInstance() {
        // since the instance variable is initialized at class loading time,
        // it's not necessary to synchronize this method */
        return instance;
    }

    /**
     * Shuts down database connections from the DataSource with the given name,
     * if applicable for the underlying provider.
     *
     * @return a database connection
     * @exception SQLException
     *              if an error occurs, or there is no DataSource with the
     *              given name.
     */
    public void shutdown(String dsName) throws SQLException {

        ConnectionProvider provider = (ConnectionProvider) providers
        .get(dsName);
        if (provider == null)
            throw new SQLException("There is no DataSource named '"
                    + dsName + "'");

        provider.shutdown();

    }    
}