高手!这样连接数据库的javabean有没有错?

连接数据库的javabean如下:

package quanxian_db;
import java.sql.*;

public class ConnOracle {
String sDBDiver="sun.jdbc.odbc.JdbcOdbcDriver";
Connection connect=null;
//Statement stmt;
ResultSet rs=null;

public ConnOracle(){
try{
Class.forName(sDBDiver);
}
catch(java.lang.ClassNotFoundException e){
System.err.println(e.getMessage());
}
}

public ResultSet executeQuery(String sql){

try{
connect=DriverManager.getConnection("jdbc:odbc:XinHaoFenxi","system","pass");
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);

}

catch(SQLException ex){
System.err.println(ex.getMessage());
}
return rs;
}

public int executeUpdate(String sql){
int result=0;
try{
connect=DriverManager.getConnection("jdbc:odbc:XinHaoFenxi","system","pass");
Statement stmt=connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
result=stmt.executeUpdate(sql);
connect.commit();//新增加的语句
}

catch(SQLException ex){
// connect.rollback();//新增加的语句
System.err.println(ex.getMessage());
}
return result;
}
}


调用javabean的jsp如下:
<%@ page contentType="text/html;charset=gb2312" %>
<%@ page language="java" import="java.sql.*" %>

<jsp:useBean id="connDb" scope="page" class="quanxian_db.ConnOracle"/>

<%
String sql ="select * from qx";
connDb.executeQuery(sql);
……
%>

后来既没有关闭连接，又没有关闭数据集．请问在哪关闭连接？书上的程序也没有关闭．会不会报错？

如果有错，正确的写法应该是怎样的？