com.mysql.jdbc.LoadBalancedAutoCommitInterceptor Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of mysql-connector-java
Show all versions of mysql-connector-java
MySQL JDBC Type 4 driver
/*
Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
The MySQL Connector/J is licensed under the terms of the GPLv2
, like most MySQL Connectors.
There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
this software, see the FLOSS License Exception
.
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;
import java.sql.SQLException;
import java.util.Properties;
/**
* @author tf221715
*
*/
public class LoadBalancedAutoCommitInterceptor implements
StatementInterceptorV2 {
private int matchingAfterStatementCount = 0;
private int matchingAfterStatementThreshold = 0;
private String matchingAfterStatementRegex;
private ConnectionImpl conn;
private LoadBalancingConnectionProxy proxy = null;
public void destroy() {
// do nothing here
}
/* (non-Javadoc)
* @see com.mysql.jdbc.StatementInterceptorV2#executeTopLevelOnly()
*/
public boolean executeTopLevelOnly() {
// always return false
return false;
}
public void init(Connection connection, Properties props) throws SQLException {
this.conn = (ConnectionImpl) connection;
String autoCommitSwapThresholdAsString = props.getProperty("loadBalanceAutoCommitStatementThreshold",
"0");
try {
this.matchingAfterStatementThreshold = Integer.parseInt(autoCommitSwapThresholdAsString);
} catch (NumberFormatException nfe) {
// nothing here, being handled in LoadBalancingConnectionProxy.
}
String autoCommitSwapRegex = props.getProperty("loadBalanceAutoCommitStatementRegex","");
if("".equals(autoCommitSwapRegex)){
return;
}
this.matchingAfterStatementRegex = autoCommitSwapRegex;
}
/* (non-Javadoc)
* @see com.mysql.jdbc.StatementInterceptorV2#postProcess(java.lang.String, com.mysql.jdbc.Statement, com.mysql.jdbc.ResultSetInternalMethods, com.mysql.jdbc.Connection, int, boolean, boolean, java.sql.SQLException)
*/
public ResultSetInternalMethods postProcess(String sql,
Statement interceptedStatement,
ResultSetInternalMethods originalResultSet, Connection connection,
int warningCount, boolean noIndexUsed, boolean noGoodIndexUsed,
SQLException statementException) throws SQLException {
// don't care if auto-commit is not enabled
if(!this.conn.getAutoCommit()){
this.matchingAfterStatementCount = 0;
// auto-commit is enabled:
} else {
if(this.proxy == null && this.conn.isProxySet()){
MySQLConnection lcl_proxy = this.conn.getLoadBalanceSafeProxy();
while(lcl_proxy != null && !(lcl_proxy instanceof LoadBalancedMySQLConnection)){
lcl_proxy = lcl_proxy.getLoadBalanceSafeProxy();
}
if(lcl_proxy != null){
this.proxy = ((LoadBalancedMySQLConnection) lcl_proxy).getProxy();
}
}
if(this.proxy != null){
// increment the match count if no regex specified, or if matches:
if(this.matchingAfterStatementRegex == null
|| sql.matches(matchingAfterStatementRegex)){
this.matchingAfterStatementCount++;
}
}
// trigger rebalance if count exceeds threshold:
if(this.matchingAfterStatementCount >= this.matchingAfterStatementThreshold){
this.matchingAfterStatementCount = 0;
try{
if(this.proxy != null){
this.proxy.pickNewConnection();
}
} catch (SQLException e){
// eat this exception, the auto-commit statement completed, but we
// could not rebalance for some reason. User may get exception
// when using connection next.
}
}
}
// always return the original result set.
return originalResultSet;
}
public ResultSetInternalMethods preProcess(String sql,
Statement interceptedStatement, Connection connection)
throws SQLException {
// we do nothing before execution, it's unsafe to swap servers at this point.
return null;
}
}