JSP数据库连接疑问（Mysql）

package com.wxpn.tutorial.db;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;
import java.util.Date;
/**
 * 描述: 数据库连接池类
 * 
 * 
 * @version 1.0
 */
public class ConnectionPool implements Runnable {
 private boolean _debug = false;
 private Thread runner;
 private Connection[] connPool;
 private int[] connStatus; // (0) available; (1) locked by the client; (2)
 // locked by the housekeeping thread
 private long[] connLockTime;
 private long[] connCreateTime;
 private String[] connID;
 private String dbdriver, dbserver, dbuser, dbpassword;
 private int currConnections, connLast, minconns, maxconns, maxconnMSec;
 // available: set to false on destroy, checked by getConnection()
 private boolean available = true;
 private SQLWarning currSQLWarning;
 /**
  * Creates a new Connection Broker<br>
  *
  * @param dbdriver
  *            JDBC driver. e.g. 'oracle.jdbc.driver.OracleDriver'<br>
  * @param dbserver
  *            JDBC connect string. e.g.
  *            'jdbc:oracle:thin:@203.92.21.109:1526:orcl'<br>
  * @param dbuser
  *            Database login name. e.g. 'Scott'<br>
  * @param dbpassword
  *            Database password. e.g. 'Tiger'<br>
  * @param minconns
  *            Minimum number of connections to start with.<br>
  * @param maxconns
  * &