Кaк лучше нaписaтъ Connection Pool?

package connectionpool;
 
import java.sql.*;
import java.util.*;
 
public class ConnectionPool {
 
  private Vector freeConn;
  private Vector busyConn;
 
  private String url;
  private String user;
  private String pass;
 
  private int maxConn = 7;
 
  public ConnectionPool(int max, String url, String user, String pass, String driver) {
    try{
      Class.forName(driver);
    }catch(Exception e){
      System.err.println('No such driver.
');
      e.printStackTrace();
      System.exit(1);
    }
 
    maxConn     = max > 0 ? max: 1;
    this.url = url;     this.user = user;    this.pass = pass;
 
    freeConn = new Vector(maxConn);
    busyConn = new Vector(maxConn);
  }
 
  public ConnectionPool(String url, String user, String pass, String driver){
    this(7, url, user, pass, driver);
  }
 
  public ConnectionPool(String url, String user, String pass){
    this(7, url, user, pass, 'sun.jdbc.odbc.JdbcOdbcDriver');
  }
 
  public synchronized Connection getConnection(){
    if(!freeConn.isEmpty()){
      Object conn = freeConn.lastElement();
      freeConn.remove(freeConn.size()-1);
      busyConn.addElement(conn);
      return (Connection)conn;
    }
    if(busyConn.size() < maxConn){
      try{
          Connection temp = DriverManager.getConnection(url, user, pass);
          busyConn.addElement(temp);
          return temp;
      }catch(SQLException e){
        System.err.println('SQLException in ConnectionPool.getConnection();
');
        e.printStackTrace();
      }
    }
 
    try{
      wait();
    }catch(InterruptedException ie){}
 
    return getConnection();
  }
 
  public void freeConnection(Connection conn){
    busyConn.remove(conn);
    freeConn.addElement(conn);
    notifyAll();
  }
}

package connectionpool;
 
import java.sql.*;
 
public class PoolManager {
 
  private static ConnectionPool cp;
 
  private static String driver, url, user, pass;
  private PoolManager() {
  }
 
  public static void setParams(int max, String driver, String url, String user, String pass){
    if(cp == null)
      cp = new ConnectionPool(max, url, user, pass, driver);
  }
 
  public static void doUpdate(String sql) throws SQLException{
    Connection c = cp.getConnection();
    c.createStatement().executeUpdate(sql);
    cp.freeConnection(c);
  }
}