//roomBean.java
public Vector list_room(String username){
        Vector vc=new Vector();
       String sql="select r_number,r_photo,if_book,r_area,r_price,r_facility,insert_time from room_info where username='"+username+"' order by insert_time desc";
       try{
         this.stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
         rs=stmt.executeQuery(sql);
         while(rs.next())
         {  bossBean bos=new bossBean();
            bos.setR_number(rs.getString("r_number"));
            bos.setR_photo(rs.getString("r_photo"));
            bos.setR_area(rs.getString("r_area"));
            bos.setR_price(rs.getString("r_price"));
            bos.setR_facility(rs.getString("r_facility"));
            bos.setInsert_time(rs.getString("insert_time"));
            bos.setIf_book(rs.getString("if_book"));
            vc.add(bos);         
         }
       
       }       
       catch(Exception e)
       {e.printStackTrace();}
       return vc;
   }

 //selectList.java
if(request.getParameter("send").equals("list_room")){
                username=(String)session.getAttribute("username"); 
                String goToPage = request.getParameter("list_room");
                Vector result=db.list_room(username,goToPage);
                request.getSession().setAttribute("list_room",(Object)result);  
                request.getSession().setAttribute("boss_info",null);  
                request.getSession().setAttribute("search",null);
                request.getSession().setAttribute("addroom",null);
                request.getSession().setAttribute("upload_success",null);
                request.getSession().setAttribute("nullresult",null); 
                RequestDispatcher rd=request.getRequestDispatcher("trader_index.jsp");
                rd.forward(request,response);
            
            }