DB connection pool using Hashtable class

Hi,

I am working on a project to build a DBConnection pool (using Hashtable(key,object)) for many database servers to use in many servlets.  I am somehow stuck at the method getConnection(), where it will return a conn for the servlet.  Basically, this method will return a connection if it is available in the pool; otherwise, it will create an instance right away and return it in the servlet.  If there is a timeout or a connection error, it will throw an exception.  

Below is my code.  I created an array in every servlet that contains the dataURLs for all servers and pass it in the object here.

Please let me know how I can fix it.  Thanks so much.

import java.util.*;
import java.sql.*;
import oracle.sql.*;

public class DBCache {

  Hashtable dbConnectionTable = new Hashtable();
  String databaseUserID = null;
  String databasePw = null;
  String databasePath = null;
  Driver d = null;

  public DBCache (String dbUID, String dbPW,
                  String dbURL []) {
    for (int i=0;i<=10;i++) {
     databaseUserID = dbUID;
     databasePw = dbPW;
     databasePath = dbURL[i];
     try
     {
      final Properties prop = new Properties();
      prop.setProperty("user", databaseUserID);
      prop.setProperty("password", databasePw);
      d = (Driver)Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
      dbConnectionTable.put(databasePath,d.connect("jdbc:oracle:thin:@"+databasePath, prop));
     }
     catch(Exception se)
     {
      se.printStackTrace();
     }
    } //for loop

  }//end of DBCache Constructor

  public Connection getConnection(String dbURL) throws  
          SQLException {

   Connection cReturn = null;
    try {
      if (databasePath.equalsIgnoreCase(dbURL)) {
        cReturn = (Connection)dbConnectionTable.get
                  (databasePath);
      }
      else {
       ?????????
      }
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
    return cReturn;
  }
 } //end of DBCache class