servletContext（）上的「無法找到符號」getRequestDispatcher

Question

protected void processRequest(HttpServletRequest request, HttpServletResponse response) 
     throws ServletException, IOException { 
    response.setContentType("text/html;charset=UTF-8"); 

    HttpSession sesion = request.getSession(); 
    PrintWriter out = response.getWriter(); 

    String num = request.getParameter("num"); 
    String password = request.getParameter("password"); 
    sesion.setAttribute("num", num); 

    Queries sql = new Queries(); 
    if (sql.login(num, password)) { 
     response.sendRedirect("private.jsp"); 
    } else { 
     request.setAttribute("error", "Error on login"); 
     RequestDispatcher dispatcher = 
     ServletContext().getRequestDispatcher("login.jsp"); // This line doesn't working 
     dispatcher.forward(request, response); 
    } 

} 

我與servletContext()錯誤。根據Netbeans 找不到符號。我想用參數重定向到login.jsp。

Answer 1

假設您選擇HttpServlet servlet上下文使用getServletContext

RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("login.jsp"); 

Answer 2

而不是採取ServletContext中發現延伸，可以使用請求範圍 轉發給下面的login.jsp是一個襯裏代碼。

request.getRequestDispatcher("login.jsp").forward(request,response);