連接數據庫oracle

import java.sql.*;

public class Connect_oracle
{
 String url="jdbc:oracle:thin:@127.0.0.1:1521:fdc";
 String username="fdc";
 String password="fdc";
 
 Connection con;
 Statement sql;
 ResultSet rs;
 
 public Connect_oracle()
 {
  try {
   Class.forName("oracle.jdbc.driver.OracleDriver");
   con=DriverManager.getConnection(url,username,password);
   sql=con.createStatement();
  } catch (Exception e) {
   e.printStackTrace();
  }   
 }

 public ResultSet executeQuery(String sqlString)
 {
  rs=null;
  try {
   rs = sql.executeQuery(sqlString);
  } catch (Exception e) {
   e.printStackTrace();
  }  
  return rs;
 }
 
 public void close()
 {
  try {
   sql.close();
   con.close();
  } catch (Exception e) {
   e.printStackTrace();
  }  
 }

 public static void main(String[] args)
 {
  Connect_oracle co=new Connect_oracle();
  ResultSet rs;
  rs=co.executeQuery("select * from zbywjbxx");
  try {
   while (rs.next())
   {
    System.out.print(rs.getString("sjbh")+"/t");
    System.out.print(rs.getString("ywdl")+"/t");
    System.out.println(rs.getString("ywxl"));
   }
  } catch (Exception e) {
   e.printStackTrace();
  }
  co.close();
 }
}