org.apache.catalina.connector.ResponseFacade.sendRedirect(Re

Question

成功完成任务后，我试图重定向到jsp，但我得到以下错误:

java.lang.IllegalStateException
at org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFacade.java:463)

我已经尝试了网上解释的大部分步骤，但其中一些没有意义。

下面是我正在做的:

           --- In Servlet ---
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    String action = request.getParameter("action");
    HttpSession session = request.getSession();
    if(action.equals("Complete Order"))
    {
        CartItems[] obj = (CartItems[])session.getAttribute("Cart");
        OrderDAO od = new OrderDAO();
        for(int i=0;i<obj.length;i++)
        {
            od.insert_order(obj[i]);
            String[] t = od.getOrderIDs(obj[i].getOrder_Date(),obj[i].getUserID());
            int len = (t.length);
            System.out.println(len);
            int l = Integer.parseInt(t[len-1]);
            System.out.println(l);
            od.insert_order_details(obj[i] ,l);
            response.sendRedirect(".\userordercomplete.jsp");
        }
    }
    else if(action.equals("Cancel Order"))
    {
        session.setAttribute("Cart", null);
        response.sendRedirect(".\user.jsp");
    }
    doGet(request, response);
}

Answer 1

问题是你在for循环中保留了重定向调用，完成所有内容并最终重定向

    for(int i=0;i<obj.length;i++)
    {
       // your stuff  
    }
    response.sendRedirect(".\userordercomplete.jsp");