进行添加评论操作,添加时，先查询用户是否登录

if ("addcomment".equals(tb_prodform.getOP())){ //进行添加评论操作,添加时，先查询用户是否登录
                              System.out.println("session.getAttribute()================================="+session.getAttribute("UserInfo"));                             
                              if(session.getAttribute("UserInfo")==null){                              
                               response.setContentType("text/html; charset=GBK");
                                 
                                  response.setHeader("Pragma","No-cache");
                                response.setHeader("Cache-Control","no-cache");
                                response.setDateHeader("Expires", 0);                  
                                 
                                 
                               String PAGEURL = "/tb_prod.do?OP=prodinfo&PRODID="+tb_prodform.getPRODID()+"";
                               if(PAGEURL.indexOf("&")>-1){
                                PAGEURL=PAGEURL.replaceAll("&","@");                              
                               }
                              
                               //System.out.println("PAGEURL=============================="+PAGEURL);
                              
                               StringBuffer buf = new StringBuffer();                         
                                     buf.append("<script language=\"JavaScript\">\n");                               
                                     buf.append("alert('您还没有登录，请先登录或者注册。');\n");
                                     buf.append("location.href='/login/loginpage.jsp?PAGEURL="+PAGEURL+"';\n");
                                     buf.append("</script>\n");                                    
                                                                   
                               PrintWriter out = response.getWriter();                               
//                              
                                  out.println(buf.toString());
                                 
                                  out.close();                         
                                 
                                  return mapping.findForward("/tb_prod.do?OP=prodinfo&PRODID="+tb_prodform.getPRODID()+"");
                                 
                              }
                               tb_prodfacade.InsertComment(tb_prodform,ui);                              
                                  return mapping.findForward("prodmain");                          
                             }