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/**
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* '$RCSfile$'
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* Purpose: A class represent a DBConnection pool. Another user can use the
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* object to initial a connection pool, get db connection or return it.
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* Copyright: 2000 Regents of the University of California and the
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* National Center for Ecological Analysis and Synthesis
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* Authors: Jing Tao
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*
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* '$Author$'
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* '$Date$'
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* '$Revision$'
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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package edu.ucsb.nceas.metacat.database;
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import java.util.Vector;
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import java.sql.*;
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sgarg
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import org.apache.log4j.Logger;
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import edu.ucsb.nceas.metacat.properties.PropertyService;
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import edu.ucsb.nceas.utilities.PropertyNotFoundException;
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1087
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/**
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* A class represent a DBConnection pool. Another user can use the
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* object to initial a connection pool, get db connection or return it.
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* This a singleton class, this means only one instance of this class could
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* be in the program at one time.
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*/
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1092
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public class DBConnectionPool implements Runnable
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{
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1089
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1087
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//static attributes
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private static DBConnectionPool instance;
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private static Vector<DBConnection> connectionPool;
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private static Thread runner;
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private static int _countOfReachMaximum = 0;
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private static Logger logMetacat = Logger.getLogger(DBConnectionPool.class);
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private static int _maxConnNum;
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private static int _initConnNum;
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private static int _incrConnNum;
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private static long _maxAge;
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private static long _maxConnTime;
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private static int _maxUsageNum;
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private static int _connCountWarnLimit;
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private static String _dbConnRecyclThrd;
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private static long _cyclTimeDbConn;
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final static int MAXIMUMCONNECTIONNUMBER;
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final static int INITIALCONNECTIONNUMBER;
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final static int INCREASECONNECTIONNUMBER;
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final static long MAXIMUMAGE;
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final static long MAXIMUMCONNECTIONTIME;
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final static int MAXIMUMUSAGENUMBER;
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final static String DBCONNECTIONRECYCLETHREAD ;
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final static long CYCLETIMEOFDBCONNECTION;
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static {
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// int maxConnNum = 0;
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// int initConnNum = 0;
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// int incrConnNum = 0;
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// long maxAge = 0;
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// long maxConnTime = 0;
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// int maxUsageNum = 0;
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// int connCountWarnLevel = 0;
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// String dbConnRecyclThrd = null;
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// long cyclTimeDbConn = 0;
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try {
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// maximum connection number in the connection pool
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_maxConnNum = Integer.parseInt(PropertyService
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.getProperty("database.maximumConnections"));
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_initConnNum = Integer.parseInt(PropertyService
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.getProperty("database.initialConnections"));
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_incrConnNum = Integer.parseInt(PropertyService
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.getProperty("database.incrementConnections"));
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_maxAge = Integer.parseInt(PropertyService
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.getProperty("database.maximumConnectionAge"));
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_maxConnTime = Long.parseLong(PropertyService
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.getProperty("database.maximumConnectionTime"));
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_maxUsageNum = Integer.parseInt(PropertyService
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.getProperty("database.maximumUsageNumber"));
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_connCountWarnLimit = Integer.parseInt(PropertyService
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.getProperty("database.connectionCountWarnLimit"));
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_dbConnRecyclThrd = PropertyService
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.getProperty("database.runDBConnectionRecycleThread");
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_cyclTimeDbConn = Long.parseLong(PropertyService
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.getProperty("database.cycleTimeOfDBConnection"));
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} catch (PropertyNotFoundException pnfe) {
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System.err.println("Could not get property in static block: "
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+ pnfe.getMessage());
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}
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MAXIMUMCONNECTIONNUMBER = _maxConnNum;
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INITIALCONNECTIONNUMBER = _initConnNum;
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INCREASECONNECTIONNUMBER = _incrConnNum;
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MAXIMUMAGE = _maxAge;
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MAXIMUMCONNECTIONTIME = _maxConnTime;
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MAXIMUMUSAGENUMBER = _maxUsageNum;
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DBCONNECTIONRECYCLETHREAD = _dbConnRecyclThrd;
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CYCLETIMEOFDBCONNECTION = _cyclTimeDbConn;
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}
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// the number for trying to check out a connection in the pool in
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// getDBConnection method
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final static int LIMIT = 2;
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final static int FREE = 0; //status of a connection
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final static int BUSY = 1; //status of a connection
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/**
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* Returns the single instance, creating one if it's the
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* first time this method is called.
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*/
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public static synchronized DBConnectionPool getInstance()
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throws SQLException
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{
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if (instance == null) {
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instance = new DBConnectionPool();
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Logger log = Logger.getLogger(DBConnectionPool.class);
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log.debug("DBConnectionPool.getInstance - MaximumConnectionNumber: " + MAXIMUMCONNECTIONNUMBER);
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log.debug("DBConnectionPool.getInstance - Intial connection number: " + INITIALCONNECTIONNUMBER);
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log.debug("DBConnectionPool.getInstance - Increated connection Number: " + INCREASECONNECTIONNUMBER);
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log.debug("DBConnectionPool.getInstance - Maximum connection age: " + MAXIMUMAGE);
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log.debug("DBConnectionPool.getInstance - Maximum connection time: " + MAXIMUMCONNECTIONTIME);
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log.debug("DBConnectionPool.getInstance - Maximum usage count: " + MAXIMUMUSAGENUMBER);
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log.debug("DBConnectionPool.getInstance - Running recycle thread or not: " + DBCONNECTIONRECYCLETHREAD);
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log.debug("DBConnectionPool.getInstance - Cycle time of recycle: " + CYCLETIMEOFDBCONNECTION);
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}
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return instance;
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}
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1089
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/**
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* This is a private constructor since it is singleton
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*/
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private DBConnectionPool() throws SQLException
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{
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connectionPool = new Vector<DBConnection>();
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initialDBConnectionPool();
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//running the thread to recycle DBConnection
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if (DBCONNECTIONRECYCLETHREAD.equals("on"))
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{
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runner = new Thread(this);
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runner.start();
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}
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}//DBConnection
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/**
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* Method to get the size of DBConnectionPool
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*/
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public int getSizeOfDBConnectionPool()
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{
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return connectionPool.size();
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}
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1087
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/**
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* Method to initial a pool of DBConnection objects
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*/
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private void initialDBConnectionPool() throws SQLException
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{
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DBConnection dbConn = null;
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for ( int i = 0; i < INITIALCONNECTIONNUMBER; i++ )
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{
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//create a new object of DBConnection
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//this DBConnection object has a new connection in it
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//it automatically generate the createtime and tag
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dbConn = new DBConnection();
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//put DBConnection into vetor
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connectionPool.add(dbConn);
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}
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}//initialDBConnectionPool
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/**
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* Method to get Connection object (Not DBConnection)
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*/
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/*public static Connection getConnection() throws SQLException
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{
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DBConnection dbConn = null;
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//get a DBConnection
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dbConn = getDBConnection();
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//get connection object in DBConnection object
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//The following getConnections method is in DBConnection class
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return dbConn.getConnections();
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}*/
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1095
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/**
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* Method to get a DBConnection in connection pool
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* 1) try to get a DBConnection from DBConnection pool
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211 |
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* 2) if 1) failed, then check the size of pool. If the size reach the
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* maximum number of connection, throw a exception: couldn't get one
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* 3) If the size is less than the maximum number of connectio, create some
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* new connections and recursive get one
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* @param methodName, the name of method which will check connection out
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*/
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217 |
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public static synchronized DBConnection getDBConnection(String methodName)
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throws SQLException
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{
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220 |
2250
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if (instance == null) {
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instance = DBConnectionPool.getInstance();
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222 |
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}
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DBConnection db = null;
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224 |
1217
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int random = 0; //random number
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225 |
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int index = 0; //index
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226 |
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int size = 0; //size of connection pool
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227 |
5319
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jones
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// logMetacat.debug("DBConnectionPool.getDBConnection - Trying to check out connection...");
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1217
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tao
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size = connectionPool.size();
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5319
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jones
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// logMetacat.debug("DBConnectionPool.getDBConnection - size of connection pool: " + size);
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1217
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tao
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//try every DBConnection in the pool
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//every DBConnection will be try LIMITE times
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for (int j=0 ; j<LIMIT; j++)
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{
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//create a random number as the started index for connection pool
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//So that the connection ofindex of 0 wouldn't be a the heaviest user
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random = (new Double (Math.random()*100)).intValue();
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for (int i=0; i<size; i++)
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239 |
1095
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{
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240 |
1217
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index =(i+random)%size;
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241 |
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db = (DBConnection) connectionPool.elementAt(index);
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242 |
5319
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jones
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// logMetacat.debug("DBConnectionPool.getDBConnection - Index: " + index);
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243 |
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// logMetacat.debug("DBConnectionPool.getDBConnection - Tag: " + db.getTag());
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// logMetacat.debug("DBConnectionPool.getDBConnection - Status: " + db.getStatus());
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245 |
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//check if the connection is free
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if (db.getStatus()==FREE)
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{
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248 |
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//If this connection is good, return this DBConnection
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249 |
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if (validateDBConnection(db))
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{
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//set this DBConnection status
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db.setStatus(BUSY);
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1122
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//increase checkout serial number
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255 |
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db.increaseCheckOutSerialNumber(1);
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256 |
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//increase one usageCount
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db.increaseUsageCount(1);
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//set method name to DBConnection
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db.setCheckOutMethodName(methodName);
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260 |
1299
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tao
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db.setAutoCommit(true);
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//debug message
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262 |
5943
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berkley
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logMetacat.debug("DBConnectionPool.getDBConnection - The connection is checked out: " + db.getTag());
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263 |
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logMetacat.debug("DBConnectionPool.getDBConnection - The method for checking is: " + db.getCheckOutMethodName());
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264 |
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logMetacat.debug("DBConnectionPool.getDBConnection - The age is " + db.getAge());
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logMetacat.debug("DBConnectionPool.getDBConnection - The usage is " + db.getUsageCount());
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logMetacat.debug("DBConnectionPool.getDBConnection - The connection time is: " + db.getConnectionTime());
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267 |
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268 |
5944
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berkley
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// System.out.println("DBConnectionPool.getDBConnection - The connection is checked out: " + db.getTag());
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269 |
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// System.out.println("DBConnectionPool.getDBConnection - The method for checking is: " + db.getCheckOutMethodName());
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// System.out.println("DBConnectionPool.getDBConnection - The age is " + db.getAge());
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// System.out.println("DBConnectionPool.getDBConnection - The usage is " + db.getUsageCount());
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// System.out.println("DBConnectionPool.getDBConnection - The connection time is: " + db.getConnectionTime());
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273 |
5943
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berkley
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274 |
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tao
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//set check out time
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275 |
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db.setCheckOutTime(System.currentTimeMillis());
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276 |
1849
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tao
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// set count of reach maximum 0 because it can check out
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277 |
5168
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daigle
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_countOfReachMaximum = 0;
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278 |
1095
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tao
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return db;
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279 |
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}//if
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280 |
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else//The DBConnection has some problem
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281 |
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{
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282 |
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//close this DBConnection
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283 |
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db.close();
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284 |
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//remove it form connection pool
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285 |
1217
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connectionPool.remove(index);
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286 |
1095
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tao
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//insert a new DBConnection to same palace
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287 |
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db = new DBConnection();
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288 |
1217
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connectionPool.insertElementAt(db, index);
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289 |
1095
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tao
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}//else
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290 |
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}//if
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291 |
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}//for
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292 |
1217
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tao
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}//for
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293 |
1095
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tao
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294 |
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//if couldn't get a connection, we should increase DBConnection pool
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295 |
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//if the connection pool size is less than maximum connection number
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296 |
1217
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tao
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297 |
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if ( size < MAXIMUMCONNECTIONNUMBER )
|
298 |
1095
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tao
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{
|
299 |
5168
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daigle
|
if ((size + INCREASECONNECTIONNUMBER) < MAXIMUMCONNECTIONNUMBER)
|
300 |
1095
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tao
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{
|
301 |
|
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//if we can create INCREASECONNECTIONNUMBER of new DBConnection
|
302 |
|
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//add to connection pool
|
303 |
5168
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daigle
|
for ( int i = 0; i < INCREASECONNECTIONNUMBER; i++)
|
304 |
1095
|
tao
|
{
|
305 |
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|
DBConnection dbConn = new DBConnection();
|
306 |
|
|
connectionPool.add(dbConn);
|
307 |
|
|
}//for
|
308 |
|
|
}//if
|
309 |
|
|
else
|
310 |
|
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{
|
311 |
|
|
//There is no enough room to increase INCREASECONNECTIONNUMBER
|
312 |
|
|
//we create new DBCoonection to Maximum connection number
|
313 |
1217
|
tao
|
for (int i= size+1; i<= MAXIMUMCONNECTIONNUMBER; i++)
|
314 |
1095
|
tao
|
{
|
315 |
|
|
DBConnection dbConn = new DBConnection();
|
316 |
|
|
connectionPool.add(dbConn);
|
317 |
|
|
}//for
|
318 |
|
|
}//else
|
319 |
|
|
|
320 |
|
|
}//if
|
321 |
|
|
else
|
322 |
|
|
{
|
323 |
1217
|
tao
|
/*throw new SQLException("The maximum of " +MAXIMUMCONNECTIONNUMBER +
|
324 |
1095
|
tao
|
" open db connections is reached." +
|
325 |
|
|
" New db connection to MetaCat" +
|
326 |
1217
|
tao
|
" cannot be established.");*/
|
327 |
5168
|
daigle
|
logMetacat.fatal("DBConnectionPool.getDBConnection - The maximum of " + MAXIMUMCONNECTIONNUMBER +
|
328 |
|
|
" open db connections is reached. New db connection to MetaCat" +
|
329 |
|
|
" cannot be established.");
|
330 |
|
|
_countOfReachMaximum ++;
|
331 |
|
|
if (_countOfReachMaximum >= 10)
|
332 |
1217
|
tao
|
{
|
333 |
5168
|
daigle
|
_countOfReachMaximum =0;
|
334 |
2663
|
sgarg
|
logMetacat.fatal("finally could not get dbconnection");
|
335 |
1849
|
tao
|
return null;
|
336 |
1217
|
tao
|
}
|
337 |
1849
|
tao
|
else
|
338 |
1217
|
tao
|
{
|
339 |
1849
|
tao
|
//if couldn't get a connection, sleep 20 seconds and try again.
|
340 |
|
|
try
|
341 |
|
|
{
|
342 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.getDBConnection - sleep 5000ms, could not get dbconnection");
|
343 |
1849
|
tao
|
Thread.sleep(5000);
|
344 |
|
|
}
|
345 |
|
|
catch (Exception e)
|
346 |
|
|
{
|
347 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.getDBConnection - General exception: " + e.getMessage());
|
348 |
1849
|
tao
|
}
|
349 |
|
|
}
|
350 |
1217
|
tao
|
|
351 |
1095
|
tao
|
|
352 |
1089
|
tao
|
}//else
|
353 |
|
|
|
354 |
|
|
//recursive to get new connection
|
355 |
1217
|
tao
|
return getDBConnection(methodName);
|
356 |
1089
|
tao
|
}//getDBConnection
|
357 |
1217
|
tao
|
|
358 |
1089
|
tao
|
/**
|
359 |
|
|
* Method to check if a db connection works fine or not
|
360 |
|
|
* Check points include:
|
361 |
|
|
* 1. check the usageCount if it is too many
|
362 |
|
|
* 2. check the dbconne age if it is too old
|
363 |
|
|
* 3. check the connection time if it is too long
|
364 |
|
|
* 4. run simple sql query
|
365 |
|
|
*
|
366 |
|
|
* @param dbConn, the DBConnection object need to check
|
367 |
|
|
*/
|
368 |
|
|
private static boolean validateDBConnection (DBConnection dbConn)
|
369 |
5168
|
daigle
|
{
|
370 |
1089
|
tao
|
//Check if the DBConnection usageCount if it is too many
|
371 |
|
|
if (dbConn.getUsageCount() >= MAXIMUMUSAGENUMBER )
|
372 |
|
|
{
|
373 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.validateDBConnection - Connection usageCount is too high: "+
|
374 |
2663
|
sgarg
|
dbConn.getUsageCount());
|
375 |
1089
|
tao
|
return false;
|
376 |
|
|
}
|
377 |
|
|
|
378 |
|
|
//Check if the DBConnection has too much connection time
|
379 |
|
|
if (dbConn.getConnectionTime() >= MAXIMUMCONNECTIONTIME)
|
380 |
|
|
{
|
381 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.validateDBConnection - Connection has too much connection time: " +
|
382 |
|
|
dbConn.getConnectionTime());
|
383 |
1089
|
tao
|
return false;
|
384 |
|
|
}
|
385 |
|
|
|
386 |
|
|
//Check if the DBConnection is too old
|
387 |
|
|
if (dbConn.getAge() >=MAXIMUMAGE)
|
388 |
|
|
{
|
389 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.validateDBConnection - Connection is too old: " + dbConn.getAge());
|
390 |
1089
|
tao
|
return false;
|
391 |
|
|
}
|
392 |
|
|
|
393 |
|
|
//Try to run a simple query
|
394 |
|
|
try
|
395 |
|
|
{
|
396 |
|
|
long startTime=System.currentTimeMillis();
|
397 |
1217
|
tao
|
DatabaseMetaData metaData = dbConn.getMetaData();
|
398 |
1089
|
tao
|
long stopTime=System.currentTimeMillis();
|
399 |
|
|
//increase one usagecount
|
400 |
|
|
dbConn.increaseUsageCount(1);
|
401 |
|
|
//increase connection time
|
402 |
|
|
dbConn.setConnectionTime(stopTime-startTime);
|
403 |
1087
|
tao
|
|
404 |
1089
|
tao
|
}
|
405 |
|
|
catch (Exception e)
|
406 |
|
|
{
|
407 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.validateDBConnection - General error:" + e.getMessage());
|
408 |
1089
|
tao
|
return false;
|
409 |
|
|
}
|
410 |
|
|
|
411 |
|
|
return true;
|
412 |
|
|
|
413 |
|
|
}//validateDBConnection()
|
414 |
|
|
|
415 |
1092
|
tao
|
/**
|
416 |
|
|
* Method to return a connection to DBConnection pool.
|
417 |
|
|
* @param conn, the Connection object need to check in
|
418 |
|
|
*/
|
419 |
1122
|
tao
|
public static synchronized void returnDBConnection(DBConnection conn,
|
420 |
|
|
int serialNumber)
|
421 |
1092
|
tao
|
{
|
422 |
|
|
int index = -1;
|
423 |
|
|
DBConnection dbConn = null;
|
424 |
|
|
|
425 |
|
|
index = getIndexOfPoolForConnection(conn);
|
426 |
|
|
if ( index ==-1 )
|
427 |
|
|
{
|
428 |
5319
|
jones
|
// logMetacat.info("DBConnectionPool.returnDBConnection - Couldn't find a DBConnection in the pool" +
|
429 |
|
|
// " which have same tag to the returned DBConnetion object");
|
430 |
1092
|
tao
|
return;
|
431 |
|
|
|
432 |
|
|
}//if
|
433 |
|
|
else
|
434 |
|
|
{
|
435 |
5168
|
daigle
|
//check the parameter - serialNumber which will be keep in calling method
|
436 |
|
|
//if it is as same as the object's checkout serial number.
|
437 |
1122
|
tao
|
//if it is same return it. If it is not same, maybe the connection already
|
438 |
5168
|
daigle
|
// was returned earlier.
|
439 |
5319
|
jones
|
// logMetacat.debug("DBConnectionPool.returnDBConnection - serial number in Connection: " +
|
440 |
|
|
// conn.getCheckOutSerialNumber());
|
441 |
|
|
// logMetacat.debug("DBConnectionPool.returnDBConnection - serial number in local: " + serialNumber);
|
442 |
1122
|
tao
|
if (conn.getCheckOutSerialNumber() == serialNumber)
|
443 |
|
|
{
|
444 |
|
|
dbConn = (DBConnection) connectionPool.elementAt(index);
|
445 |
|
|
//set status to free
|
446 |
|
|
dbConn.setStatus(FREE);
|
447 |
|
|
//count connection time
|
448 |
|
|
dbConn.setConnectionTime
|
449 |
1092
|
tao
|
(System.currentTimeMillis()-dbConn.getCheckOutTime());
|
450 |
1095
|
tao
|
|
451 |
1122
|
tao
|
//set check out time to 0
|
452 |
|
|
dbConn.setCheckOutTime(0);
|
453 |
1217
|
tao
|
|
454 |
5319
|
jones
|
// logMetacat.debug("DBConnectionPool.returnDBConnection - Connection: " +
|
455 |
|
|
// dbConn.getTag() + " checked in.");
|
456 |
|
|
// logMetacat.debug("DBConnectionPool.returnDBConnection - Connection: " +
|
457 |
|
|
// dbConn.getTag() + "'s status: " + dbConn.getStatus());
|
458 |
1217
|
tao
|
|
459 |
1122
|
tao
|
}//if
|
460 |
1217
|
tao
|
else
|
461 |
|
|
{
|
462 |
5319
|
jones
|
// logMetacat.info("DBConnectionPool.returnDBConnection - This DBConnection couldn't return" +
|
463 |
|
|
// dbConn.getTag());
|
464 |
1217
|
tao
|
}//else
|
465 |
1092
|
tao
|
}//else
|
466 |
|
|
|
467 |
|
|
|
468 |
|
|
}//returnConnection
|
469 |
|
|
|
470 |
|
|
/**
|
471 |
|
|
* Given a returned DBConnection, try to find the index of DBConnection object
|
472 |
|
|
* in dbConnection pool by comparing DBConnection' tag and conn.toString.
|
473 |
|
|
* If couldn't find , -1 will be returned.
|
474 |
|
|
* @param conn, the connection need to be found
|
475 |
|
|
*/
|
476 |
|
|
private static synchronized int getIndexOfPoolForConnection(DBConnection conn)
|
477 |
|
|
{
|
478 |
|
|
int index = -1;
|
479 |
|
|
String info = null;
|
480 |
1217
|
tao
|
//if conn is null return -1 too
|
481 |
|
|
if (conn==null)
|
482 |
|
|
{
|
483 |
|
|
return -1;
|
484 |
|
|
}
|
485 |
1092
|
tao
|
//get tag of this returned DBConnection
|
486 |
|
|
info = conn.getTag();
|
487 |
|
|
//if the tag is null or empty, -1 will be returned
|
488 |
|
|
if (info==null || info.equals(""))
|
489 |
|
|
{
|
490 |
|
|
return index;
|
491 |
|
|
}
|
492 |
|
|
//compare this info to the tag of every DBConnection in the pool
|
493 |
|
|
for ( int i=0; i< connectionPool.size(); i++)
|
494 |
|
|
{
|
495 |
|
|
DBConnection dbConn = (DBConnection) connectionPool.elementAt(i);
|
496 |
|
|
if (info.equals(dbConn.getTag()))
|
497 |
|
|
{
|
498 |
|
|
index = i;
|
499 |
|
|
break;
|
500 |
|
|
}//if
|
501 |
|
|
}//for
|
502 |
|
|
|
503 |
|
|
return index;
|
504 |
|
|
}//getIndexOfPoolForConnection
|
505 |
|
|
|
506 |
|
|
/**
|
507 |
|
|
* Method to shut down all connections
|
508 |
|
|
*/
|
509 |
|
|
public static void release()
|
510 |
|
|
{
|
511 |
|
|
|
512 |
5168
|
daigle
|
//shut down the background recycle thread
|
513 |
1095
|
tao
|
if (DBCONNECTIONRECYCLETHREAD.equals("on"))
|
514 |
|
|
{
|
515 |
|
|
runner.interrupt();
|
516 |
|
|
}
|
517 |
5168
|
daigle
|
//close every dbconnection in the pool
|
518 |
1092
|
tao
|
synchronized(connectionPool)
|
519 |
|
|
{
|
520 |
|
|
for (int i=0;i<connectionPool.size();i++)
|
521 |
|
|
{
|
522 |
|
|
try
|
523 |
|
|
{
|
524 |
|
|
DBConnection dbConn= (DBConnection) connectionPool.elementAt(i);
|
525 |
|
|
dbConn.close();
|
526 |
|
|
}//try
|
527 |
|
|
catch (SQLException e)
|
528 |
|
|
{
|
529 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.release - Error in release connection: "
|
530 |
2663
|
sgarg
|
+e.getMessage());
|
531 |
1092
|
tao
|
}//catch
|
532 |
|
|
}//for
|
533 |
|
|
}//synchronized
|
534 |
|
|
}//release()
|
535 |
|
|
|
536 |
|
|
/**
|
537 |
|
|
* periodically to recycle the connection
|
538 |
|
|
*/
|
539 |
|
|
public void run()
|
540 |
|
|
{
|
541 |
|
|
DBConnection dbConn = null;
|
542 |
|
|
//keep the thread running
|
543 |
|
|
while (true)
|
544 |
|
|
{
|
545 |
|
|
//check every dbconnection in the pool
|
546 |
|
|
synchronized(connectionPool)
|
547 |
|
|
{
|
548 |
|
|
for (int i=0; i<connectionPool.size(); i++)
|
549 |
|
|
{
|
550 |
|
|
dbConn = (DBConnection) connectionPool.elementAt(i);
|
551 |
1095
|
tao
|
|
552 |
1122
|
tao
|
//if a DBConnection conncectioning time for one check out is greater
|
553 |
|
|
//than 30000 milliseconds print it out
|
554 |
|
|
if (dbConn.getStatus()==BUSY &&
|
555 |
|
|
(System.currentTimeMillis()-dbConn.getCheckOutTime())>=30000)
|
556 |
1095
|
tao
|
{
|
557 |
5168
|
daigle
|
logMetacat.fatal("DBConnectionPool.run - This DBConnection is checked out for: " +
|
558 |
|
|
(System.currentTimeMillis()-dbConn.getCheckOutTime())/1000 + " secs");
|
559 |
|
|
logMetacat.fatal("DBConnectionPool.run - " + dbConn.getTag());
|
560 |
|
|
logMetacat.error("DBConnectionPool.run - method: " + dbConn.getCheckOutMethodName());
|
561 |
1095
|
tao
|
|
562 |
|
|
}
|
563 |
|
|
|
564 |
|
|
//check the validation of free connection in the pool
|
565 |
1092
|
tao
|
if (dbConn.getStatus() == FREE)
|
566 |
|
|
{
|
567 |
|
|
try
|
568 |
|
|
{
|
569 |
|
|
//try to print out the warning message for every connection
|
570 |
1122
|
tao
|
if (dbConn.getWarningMessage()!=null)
|
571 |
|
|
{
|
572 |
5168
|
daigle
|
logMetacat.warn("DBConnectionPool.run - Warning for connection " +
|
573 |
|
|
dbConn.getTag() + " : " + dbConn.getWarningMessage());
|
574 |
1122
|
tao
|
}
|
575 |
5933
|
berkley
|
logMetacat.info("Checking if the db connection " + dbConn.toString() + " is valid according to metacat.properties parameters.");
|
576 |
|
|
System.out.println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Checking if the db connection " + dbConn.toString() + " is valid according to metacat.properties parameters.");
|
577 |
1092
|
tao
|
//check if it is valiate, if not create new one and replace old one
|
578 |
|
|
if (!validateDBConnection(dbConn))
|
579 |
|
|
{
|
580 |
5933
|
berkley
|
System.out.println("DB connection is not valid! Releasing it.");
|
581 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.run - Recyle: " + dbConn.getTag());
|
582 |
1092
|
tao
|
//close this DBConnection
|
583 |
|
|
dbConn.close();
|
584 |
|
|
//remove it form connection pool
|
585 |
|
|
connectionPool.remove(i);
|
586 |
|
|
//insert a new DBConnection to same palace
|
587 |
|
|
dbConn = new DBConnection();
|
588 |
|
|
connectionPool.insertElementAt(dbConn, i);
|
589 |
5933
|
berkley
|
System.out.println("@@@@@@@@@@@@@@@@@@@@@@@@@db connection released: " + dbConn.toString());
|
590 |
1122
|
tao
|
}//if
|
591 |
1092
|
tao
|
}//try
|
592 |
|
|
catch (SQLException e)
|
593 |
|
|
{
|
594 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.run - SQL error: " + e.getMessage());
|
595 |
1092
|
tao
|
}//catch
|
596 |
5933
|
berkley
|
|
597 |
|
|
System.out.println("number of connections in pool: " + connectionPool.size());
|
598 |
|
|
System.out.println("connection pool capacity: " + connectionPool.capacity());
|
599 |
|
|
|
600 |
1092
|
tao
|
}//if
|
601 |
|
|
}//for
|
602 |
|
|
}//synchronize
|
603 |
1095
|
tao
|
//Thread sleep
|
604 |
1092
|
tao
|
try
|
605 |
|
|
{
|
606 |
1095
|
tao
|
Thread.sleep(CYCLETIMEOFDBCONNECTION);
|
607 |
1092
|
tao
|
}
|
608 |
|
|
catch (Exception e)
|
609 |
|
|
{
|
610 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.run - General error: " + e.getMessage());
|
611 |
1092
|
tao
|
}
|
612 |
|
|
}//while
|
613 |
|
|
}//run
|
614 |
|
|
|
615 |
1217
|
tao
|
/**
|
616 |
|
|
* Method to get the number of free DBConnection in DBConnection pool
|
617 |
|
|
*/
|
618 |
5168
|
daigle
|
private static synchronized int getFreeDBConnectionNumber()
|
619 |
1217
|
tao
|
{
|
620 |
|
|
int numberOfFreeDBConnetion = 0; //return number
|
621 |
|
|
DBConnection db = null; //single DBconnection
|
622 |
|
|
int poolSize = 0; //size of connection pool
|
623 |
|
|
//get the size of DBConnection pool
|
624 |
|
|
poolSize = connectionPool.size();
|
625 |
|
|
//Check every DBConnection in the pool
|
626 |
|
|
for ( int i=0; i<poolSize; i++)
|
627 |
|
|
{
|
628 |
|
|
|
629 |
|
|
db = (DBConnection) connectionPool.elementAt(i);
|
630 |
|
|
//check the status of db. If it is free, count it
|
631 |
|
|
if (db.getStatus() == FREE)
|
632 |
|
|
{
|
633 |
|
|
numberOfFreeDBConnetion++;
|
634 |
|
|
}//if
|
635 |
|
|
}//for
|
636 |
|
|
//return the count result
|
637 |
|
|
return numberOfFreeDBConnetion;
|
638 |
|
|
}//getFreeDBConnectionNumber
|
639 |
|
|
|
640 |
5168
|
daigle
|
/**
|
641 |
|
|
* Print a list of busy connections. This method should be called when the
|
642 |
|
|
* used connection count exceeds the _connCountWarnLimit set in
|
643 |
|
|
* metacat.properties.
|
644 |
|
|
*
|
645 |
|
|
* @param usedConnectionCount
|
646 |
|
|
* the current count of busy connections
|
647 |
|
|
*/
|
648 |
|
|
private static void printBusyDBConnections(int usedConnectionCount) {
|
649 |
|
|
boolean showCountWarning = usedConnectionCount > _connCountWarnLimit;
|
650 |
|
|
|
651 |
|
|
String warnMessage = "";
|
652 |
|
|
|
653 |
|
|
// Check every DBConnection in the pool
|
654 |
|
|
for (DBConnection dbConnection : connectionPool) {
|
655 |
|
|
// check the status of db. If it is busy, add it to the message
|
656 |
|
|
if (dbConnection.getStatus() == BUSY) {
|
657 |
|
|
if (showCountWarning) {
|
658 |
|
|
warnMessage += "\n --- Method: " + dbConnection.getCheckOutMethodName() +
|
659 |
|
|
" is using: " + dbConnection.getTag() + " for " + dbConnection.getAge() + " ms ";
|
660 |
|
|
}
|
661 |
|
|
|
662 |
|
|
if (dbConnection.getConnectionTime() > _maxConnTime) {
|
663 |
|
|
logMetacat.warn("DBConnectionPool.printBusyDBConnections - Excessive connection time, method: " +
|
664 |
|
|
dbConnection.getCheckOutMethodName() + " is using: " + dbConnection.getTag() +
|
665 |
|
|
" for " + dbConnection.getConnectionTime() + " ms ");
|
666 |
|
|
}
|
667 |
|
|
}// if
|
668 |
|
|
}// for
|
669 |
|
|
|
670 |
|
|
if (showCountWarning) {
|
671 |
|
|
logMetacat.warn("DBConnectionPool.printBusyDBConnections - " + usedConnectionCount +
|
672 |
|
|
" DB connections currently busy because: " + warnMessage);
|
673 |
|
|
}
|
674 |
|
|
}
|
675 |
1217
|
tao
|
|
676 |
1219
|
tao
|
/**
|
677 |
5168
|
daigle
|
* Method to decrease dbconnection pool size when all dbconnections are idle
|
678 |
|
|
* If all connections are free and connection pool size greater than initial
|
679 |
|
|
* value, shrink connection pool size to initial value
|
680 |
|
|
*/
|
681 |
1220
|
tao
|
public static synchronized boolean shrinkConnectionPoolSize()
|
682 |
1219
|
tao
|
{
|
683 |
|
|
int connectionPoolSize = 0; //store the number of dbconnection pool size
|
684 |
|
|
int freeConnectionSize = 0; //store the number of free dbconnection in pool
|
685 |
|
|
int difference = 0; // store the difference number between connection size
|
686 |
|
|
// and free connection
|
687 |
5168
|
daigle
|
boolean hasException = false; //to check if has a exception happened
|
688 |
1220
|
tao
|
boolean result = false; //result
|
689 |
|
|
DBConnection conn = null; // the dbconnection
|
690 |
1219
|
tao
|
connectionPoolSize = connectionPool.size();
|
691 |
|
|
freeConnectionSize = getFreeDBConnectionNumber();
|
692 |
2716
|
sgarg
|
difference = connectionPoolSize - freeConnectionSize;
|
693 |
|
|
|
694 |
2714
|
sgarg
|
if(freeConnectionSize < connectionPoolSize){
|
695 |
5168
|
daigle
|
logMetacat.info("DBConnectionPool.shrinkConnectionPoolSize - " + difference + " connection(s) " +
|
696 |
|
|
"being used and connection pool size is " + connectionPoolSize);
|
697 |
2714
|
sgarg
|
} else {
|
698 |
5168
|
daigle
|
logMetacat.info("DBConnectionPool.shrinkConnectionPoolSize - Connection pool size: " + connectionPoolSize);
|
699 |
|
|
logMetacat.info("DBConnectionPool.shrinkConnectionPoolSize - Free Connection number: " + freeConnectionSize);
|
700 |
2714
|
sgarg
|
}
|
701 |
1219
|
tao
|
|
702 |
|
|
//If all connections are free and connection pool size greater than
|
703 |
|
|
//initial value, shrink connection pool size to intital value
|
704 |
|
|
if (difference == 0 && connectionPoolSize > INITIALCONNECTIONNUMBER)
|
705 |
|
|
{
|
706 |
1220
|
tao
|
//db connection having index from to connectionpoolsize -1
|
707 |
|
|
//intialConnectionnumber should be close and remove from pool
|
708 |
|
|
for ( int i=connectionPoolSize-1; i >= INITIALCONNECTIONNUMBER ; i--)
|
709 |
1219
|
tao
|
{
|
710 |
1220
|
tao
|
|
711 |
1219
|
tao
|
//get the dbconnection from pool
|
712 |
|
|
conn = (DBConnection) connectionPool.elementAt(i);
|
713 |
|
|
|
714 |
|
|
try
|
715 |
|
|
{
|
716 |
1220
|
tao
|
//close conn
|
717 |
1219
|
tao
|
conn.close();
|
718 |
|
|
}//try
|
719 |
|
|
catch (SQLException e)
|
720 |
1220
|
tao
|
{
|
721 |
5168
|
daigle
|
// set hadException true
|
722 |
1220
|
tao
|
hasException = true;
|
723 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.shrinkConnectionPoolSize - SQL Exception: " + e.getMessage());
|
724 |
1219
|
tao
|
}//catch
|
725 |
1220
|
tao
|
|
726 |
|
|
//remove it from pool
|
727 |
|
|
connectionPool.remove(i);
|
728 |
5168
|
daigle
|
// because enter the loop, set result true
|
729 |
1220
|
tao
|
result = true;
|
730 |
1219
|
tao
|
}//for
|
731 |
|
|
}//if
|
732 |
1220
|
tao
|
|
733 |
|
|
//if hasException is true ( there at least once exception happend)
|
734 |
|
|
// the result should be false
|
735 |
|
|
if (hasException)
|
736 |
|
|
{
|
737 |
|
|
result =false;
|
738 |
|
|
}//if
|
739 |
|
|
// return result
|
740 |
|
|
return result;
|
741 |
1219
|
tao
|
}//shrinkDBConnectionPoolSize
|
742 |
1220
|
tao
|
|
743 |
|
|
/**
|
744 |
|
|
* Method to decrease dbconnection pool size when all dbconnections are idle
|
745 |
|
|
* If all connections are free and connection pool size greater than
|
746 |
|
|
* initial value, shrink connection pool size to intital value
|
747 |
|
|
*/
|
748 |
|
|
public static synchronized void shrinkDBConnectionPoolSize()
|
749 |
|
|
{
|
750 |
|
|
int connectionPoolSize = 0; //store the number of dbconnection pool size
|
751 |
|
|
int freeConnectionSize = 0; //store the number of free dbconnection in pool
|
752 |
5168
|
daigle
|
int usedConnectionCount = 0; // store the difference number between connection size
|
753 |
1220
|
tao
|
// and free connection
|
754 |
|
|
|
755 |
|
|
DBConnection conn = null; // the dbconnection
|
756 |
|
|
connectionPoolSize = connectionPool.size();
|
757 |
|
|
freeConnectionSize = getFreeDBConnectionNumber();
|
758 |
5168
|
daigle
|
usedConnectionCount = connectionPoolSize - freeConnectionSize;
|
759 |
2716
|
sgarg
|
|
760 |
5168
|
daigle
|
printBusyDBConnections(usedConnectionCount);
|
761 |
|
|
|
762 |
2716
|
sgarg
|
if(freeConnectionSize < connectionPoolSize){
|
763 |
5168
|
daigle
|
logMetacat.info("DBConnectionPool.shrinkDBConnectionPoolSize - " + usedConnectionCount + " connection(s) " +
|
764 |
|
|
"being used and connection pool size is " + connectionPoolSize);
|
765 |
2716
|
sgarg
|
} else {
|
766 |
5168
|
daigle
|
logMetacat.debug("DBConnectionPool.shrinkDBConnectionPoolSize - " +
|
767 |
|
|
"Connection pool size: " + connectionPoolSize);
|
768 |
|
|
logMetacat.debug("DBConnectionPool.shrinkDBConnectionPoolSize - " +
|
769 |
|
|
"Free Connection number: " + freeConnectionSize);
|
770 |
2716
|
sgarg
|
}
|
771 |
1219
|
tao
|
|
772 |
1220
|
tao
|
//If all connections are free and connection pool size greater than
|
773 |
|
|
//initial value, shrink connection pool size to intital value
|
774 |
5168
|
daigle
|
if (usedConnectionCount == 0 && connectionPoolSize > INITIALCONNECTIONNUMBER)
|
775 |
1220
|
tao
|
{
|
776 |
|
|
//db connection having index from to connectionpoolsize -1
|
777 |
|
|
//intialConnectionnumber should be close and remove from pool
|
778 |
|
|
for ( int i=connectionPoolSize-1; i >= INITIALCONNECTIONNUMBER ; i--)
|
779 |
|
|
{
|
780 |
|
|
|
781 |
|
|
//get the dbconnection from pool
|
782 |
|
|
conn = (DBConnection) connectionPool.elementAt(i);
|
783 |
|
|
//make sure again the DBConnection status is free
|
784 |
|
|
if (conn.getStatus()==FREE)
|
785 |
|
|
{
|
786 |
|
|
try
|
787 |
|
|
{
|
788 |
|
|
//close conn
|
789 |
|
|
conn.close();
|
790 |
|
|
}//try
|
791 |
|
|
catch (SQLException e)
|
792 |
|
|
{
|
793 |
|
|
|
794 |
5168
|
daigle
|
logMetacat.error("DBConnectionPool.shrinkDBConnectionPoolSize - SQL error: " + e.getMessage());
|
795 |
1220
|
tao
|
}//catch
|
796 |
|
|
|
797 |
|
|
//remove it from pool
|
798 |
|
|
connectionPool.remove(i);
|
799 |
|
|
}//if
|
800 |
|
|
|
801 |
|
|
}//for
|
802 |
|
|
}//if
|
803 |
|
|
|
804 |
|
|
|
805 |
|
|
}//shrinkDBConnectionPoolSize
|
806 |
1219
|
tao
|
|
807 |
|
|
|
808 |
1087
|
tao
|
}//DBConnectionPool
|