重定向执行完成后，不能在页面刷新显示内容

重定向执行完成后，不能跳到指定页面进行刷新显示吗？能执行，jsp页面没有立即显示添加的内容

 resp.sendRedirect(req.getServletContext().getContextPath()+"/updatedetail");

```java
@WebServlet("/updatedetail")
public class updatedetail extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        HttpSession httpSession=req.getSession();
        Integer food_id=(Integer) httpSession.getAttribute("fdid");
        
        System.out.println("tainanl"+food_id);
        
        pinglundao pldao=new pinglundao();
        List pList=pldao.findbyid(food_id);
        System.out.println("msg"+pList);
        for (pinglun pinglun : pList) {
            //通过评论id查询所有的评论回复信息
            List rList=pldao.findBymsgid(pinglun.getMsg_id());
            

            pinglun.setReplies(rList);
            
        }
        
        req.getSession().setAttribute("msgs", pList); 
        req.getRequestDispatcher("detail.jsp").forward(req, resp);
    }
}

```

重新刷新的时候取了新数据吗？是不是相关的参数没带过去