一自学者的问题：JSP连接数据库的问题。

Java code:

<%@ page language="java" contentType="text/html; charset=gbk"
pageEncoding="gbk"%>
<%@ page import="java.sql.*"%>
<%!
String str="";

private void tree(Connection conn,int id){
ResultSet rs=null;
Statement stmt=null;
String sql="select * form article where pid= "+id;

try{

stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
while(rs.next()){
str += "<tr><td>"+rs.getInt("id")+"</td><td>"+rs.getString("title")+"</td></tr>";
if(rs.getInt("isleaf")!=0){
tree(conn,rs.getInt("id"));
}
}
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
if(rs!=null){
rs.close();
rs=null;
}
if(stmt!=null){
stmt.close();
stmt=null;
}}catch(SQLException e){
e.printStackTrace();
}
}

}
%>
<%
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;Databasename=bbs","sa","sa&q