Question

Servlet向jsp传值，为什么jsp页面总是null呢？求解

servlet：public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); String username=request.getParameter("txt1"); request.setAttribute("username",username); RequestDispatcher rd = request.getRequestDispatcher("/WebRoot/charesult.jsp"); rd.forward(request, response); }jsp：<%String username=(String)request.getAttribute("username");out.println(username);%>

Answer 1

你的代码都是正确的，你可以调试看看，看你servlet页面的String username=request.getParameter("txt1")是否有值，单看你页面的代码，是没有错误的，只有这里可能没有得到值，导致jsp页面是null