/* Copyright (C) 2002-2006 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as  published by the Free Software Foundation. There are special exceptions to the terms and conditions of the GPL  as it is applied to this software. View the full text of the  exception in file EXCEPTIONS-CONNECTOR-J in the directory of this  software distribution. 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */package com.mysql.jdbc.integration.jboss;import java.io.Serializable;import java.lang.reflect.Method;import java.sql.Connection;import java.sql.SQLException;import java.sql.Statement;import org.jboss.resource.adapter.jdbc.ValidConnectionChecker;import com.mysql.jdbc.SQLError;/** * A more efficient connection checker for JBoss. *  * @version $Id: MysqlValidConnectionChecker.java,v 1.1.2.1 2005/05/13 18:58:42 *          mmatthews Exp $ */public final class MysqlValidConnectionChecker implements		ValidConnectionChecker, Serializable {	private static final long serialVersionUID = 3258689922776119348L;	private Method pingMethod;		private Method pingMethodWrapped;	private final static Object[] NO_ARGS_OBJECT_ARRAY = new Object[0];	public MysqlValidConnectionChecker() {		try {			// Avoid classloader goofiness			Class mysqlConnection = Thread.currentThread()					.getContextClassLoader().loadClass(							"com.mysql.jdbc.Connection");			pingMethod = mysqlConnection.getMethod("ping", null);						Class mysqlConnectionWrapper = Thread.currentThread()			.getContextClassLoader().loadClass(					"com.mysql.jdbc.jdbc2.optional.ConnectionWrapper");						pingMethodWrapped = mysqlConnectionWrapper.getMethod("ping", null);		} catch (Exception ex) {			// Punt, we'll use 'SELECT 1' to do the check		}	}	/*	 * (non-Javadoc)	 * 	 * @see org.jboss.resource.adapter.jdbc.ValidConnectionChecker#isValidConnection(java.sql.Connection)	 */	public SQLException isValidConnection(Connection conn) {		if (conn instanceof com.mysql.jdbc.Connection) {			if (pingMethod != null) {				try {					this.pingMethod.invoke(conn, null);						return null;				} catch (Exception ex) {					if (ex instanceof SQLException) {						return (SQLException) ex;					}						return SQLError.createSQLException("Ping failed: " + ex.toString());				}			}		} else if (conn instanceof com.mysql.jdbc.jdbc2.optional.ConnectionWrapper) {			if (pingMethodWrapped != null) {				try {					this.pingMethodWrapped.invoke(conn, null);						return null;				} catch (Exception ex) {					if (ex instanceof SQLException) {						return (SQLException) ex;					}						return SQLError.createSQLException("Ping failed: " + ex.toString());				}			}		}		// Punt and use 'SELECT 1'		Statement pingStatement = null;		try {			pingStatement = conn.createStatement();						pingStatement.executeQuery("SELECT 1").close();			return null;		} catch (SQLException sqlEx) {			return sqlEx;		} finally {			if (pingStatement != null) {				try {					pingStatement.close();				} catch (SQLException sqlEx) {					// can't do anything about it here				}			}		}	}}