ProfilerEventHandlerFactory.java

/*
 Copyright  2002-2007 MySQL AB, 2008 Sun Microsystems
 All rights reserved. Use is subject to license terms.

  The MySQL Connector/J is licensed under the terms of the GPL,
  like most MySQL Connectors. There are special exceptions to the
  terms and conditions of the GPL as it is applied to this software,
  see the FLOSS License Exception available on mysql.com.

  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; version 2 of the
  License.

  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; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  02110-1301 USA

 */

package com.mysql.jdbc.profiler;

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

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.ConnectionImpl;
import com.mysql.jdbc.Util;
import com.mysql.jdbc.log.Log;

/**
 * @author mmatthew
 */
public class ProfilerEventHandlerFactory {

	private static final Map CONNECTIONS_TO_SINKS = new HashMap();

	private Connection ownerConnection = null;

	private Log log = null;

	/**
	 * Returns the ProfilerEventHandlerFactory that handles profiler events for the given
	 * connection.
	 * 
	 * @param conn
	 *            the connection to handle events for
	 * @return the ProfilerEventHandlerFactory that handles profiler events
	 */
	public static synchronized ProfilerEventHandler getInstance(ConnectionImpl conn) throws SQLException {
		ProfilerEventHandler handler = (ProfilerEventHandler) CONNECTIONS_TO_SINKS
				.get(conn);

		if (handler == null) {
			handler = (ProfilerEventHandler)Util.getInstance(conn.getProfilerEventHandler(), new Class[0], new Object[0], conn.getExceptionInterceptor());
			
			// we do it this way to not require
			// exposing the connection properties 
			// for all who utilize it
			conn.initializeExtension(handler);
			
			CONNECTIONS_TO_SINKS.put(conn, handler);
		}

		return handler;
	}

	public static synchronized void removeInstance(Connection conn) {
		ProfilerEventHandler handler = (ProfilerEventHandler) CONNECTIONS_TO_SINKS.remove(conn);
		
		if (handler != null) {
			handler.destroy();
		}
	}

	private ProfilerEventHandlerFactory(Connection conn) {
		this.ownerConnection = conn;

		try {
			this.log = this.ownerConnection.getLog();
		} catch (SQLException sqlEx) {
			throw new RuntimeException("Unable to get logger from connection");
		}
	}
}