无法访问java servlet中的请求参数

Question

我对两种不同的表单数据使用相同的dpPost方法。我无法访问第二种形式的请求参数。

 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

   if("schema".equals(session.getAttribute("which"))) {
             second_html();
             //call second page here
             }

             String btnClicked= request.getParameter("p2"); // This is getting null after submitting second_html()
       if("edit".equals(session.getAttribute("which"))){
     /*   process second page here after Submit on the second page
                   I am trying to access request.getParameter() but value is null                  here for the fields in the second page       */
                 second_html();
    }
   }
  first_html() {
   // have form and submit button
   session.setAttribute("which","schema");

}
second_html() {
 // have form and submit button
  <input type='text' name='p2' id='p2' size='3' >
 session.setAttribute("which","edit");
}

编辑：我的会话getter工作正常。但是request.getParameter无效。

Answer 1

您正在访问会话变量，而不是您的请求参数。

您可以使用

访问它们

request.getParameter("which")

Answer 2

如果我理解您的问题，您应该使用ServletRequest.getParameter(String)，

String v = request.getParameter("which");
if (v.equals("schema")) {

} else if (v.equals("edit")) {

}