/*
* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.resource.adapter.jdbc.vendor;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.jboss.logging.Logger;
import org.jboss.resource.adapter.jdbc.ValidConnectionChecker;
/**
* <p>This class is an implementation of ValidConnectionChecker for MySQL
* ReplicatedDriver. It supports both isValid and ping methods on the
* connection object.
*
* <p>Please note that the isValid method requires java 6 classes to be present.
*
* <p>The code was inspired by MySQLValidConnectionChecker. See it's javadoc for
* authors info. This code is released under the LGPL license.
*
* @author Luc Boudreau (lucboudreau att gmail dott com)
*
*/
public class MySQLReplicationValidConnectionChecker implements ValidConnectionChecker, Serializable
{
/**
* Serial version ID
*/
private static final long serialVersionUID = 2658231045989623858L;
/**
* Tells if the connection supports the isValid method.
* (Java 6 only)
*/
private boolean driverHasIsValidMethod;
private transient Method isValid;
/**
* Tells if the connection supports the ping method.
*/
private boolean driverHasPingMethod;
private transient Method ping;
/**
* Classname of the supported connection
*/
protected final static String CONNECTION_CLASS = "com.mysql.jdbc.ReplicationConnection";
/**
* Log access object
*/
private static transient Logger log;
// The timeout (apparently the timeout is ignored?)
private static Object[] timeoutParam = new Object[] {};
/**
* Initiates the ValidConnectionChecker implementation.
*/
public MySQLReplicationValidConnectionChecker()
{
try
{
initPing();
}
catch (Exception e)
{
log.warn("Cannot find the driver class defined in CONNECTION_CLASS. Will use 'SELECT 1' instead.", e);
}
}
/* (non-Javadoc)
* @see org.jboss.resource.adapter.jdbc.ValidConnectionChecker#isValidConnection(java.sql.Connection)
*/
public SQLException isValidConnection(Connection c)
{
if (driverHasIsValidMethod)
{
try
{
isValid.invoke(c, timeoutParam);
}
catch (Exception e)
{
if (e instanceof SQLException)
{
return (SQLException) e;
}
else
{
log.warn("Unexpected error in ping", e);
return new SQLException("ping failed: " + e.toString());
}
}
}
else if (driverHasPingMethod)
{
//if there is a ping method then use it
try
{
ping.invoke(c, timeoutParam);
}
catch (Exception e)
{
if (e instanceof SQLException)
{
return (SQLException) e;
}
else
{
log.warn("Unexpected error in ping", e);
return new SQLException("ping failed: " + e.toString());
}
}
}
else
{
//otherwise just use a 'SELECT 1' statement
Statement stmt = null;
ResultSet rs = null;
try
{
stmt = c.createStatement();
rs = stmt.executeQuery("SELECT 1");
}
catch (Exception e)
{
if (e instanceof SQLException)
{
return (SQLException) e;
}
else
{
log.warn("Unexpected error in ping (SELECT 1)", e);
return new SQLException("ping (SELECT 1) failed: " + e.toString());
}
}
finally
{
// Cleanup everything and make sure to handle
// sql exceptions occuring
try
{
if (rs != null)
rs.close();
}
catch (SQLException e)
{
}
try
{
if (stmt != null)
stmt.close();
}
catch (SQLException e)
{
}
}
}
return null;
}
private void initPing() throws ClassNotFoundException, NoSuchMethodException
{
driverHasIsValidMethod = false;
driverHasPingMethod = false;
log = Logger.getLogger(MySQLReplicationValidConnectionChecker.class);
// Load connection class
Class mysqlConnection = Thread.currentThread().getContextClassLoader().loadClass( CONNECTION_CLASS );
// Check for Java 6 compatibility and use isValid on the connection
try
{
isValid = mysqlConnection.getMethod("isValid", new Class[] {});
driverHasIsValidMethod = true;
}
catch (NoSuchMethodException e)
{
// Notify someone
log.info("Cannot resolve com.mysq.jdbc.ReplicationConnection.isValid method. Fallback to ping.", e);
}
catch (SecurityException e)
{
// Notify someone
log.info("Cannot resolve com.mysq.jdbc.ReplicationConnection.isValid method. Fallback to ping.", e);
}
if (!driverHasIsValidMethod)
{
try
{
// Check for ping method
ping = mysqlConnection.getMethod("ping", new Class[] {});
driverHasPingMethod = true;
}
catch (NoSuchMethodException e)
{
// Notify someone
log.warn("Cannot resolve com.mysq.jdbc.ReplicationConnection.ping method. Will use 'SELECT 1' instead.", e);
}
catch (SecurityException e)
{
// Notify someone
log.info("Cannot resolve com.mysq.jdbc.ReplicationConnection.ping method. Will use 'SELECT 1' instead.", e);
}
}
}
private void writeObject(ObjectOutputStream stream) throws IOException
{
// nothing
}
private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
{
try
{
initPing();
}
catch (Exception e)
{
IOException ioe = new IOException("Unable to resolve ping method: " + e.getMessage());
ioe.initCause(e);
throw ioe;
}
}
}