無法訪問java servlets中的請求參數

Question

我對兩種不同的表單數據使用相同的dpPost方法。我無法訪問第二種形式的請求參數。

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"); 
} 

編輯：我的會話getters工作正常。但是request.getParameter不起作用。

Answer 1

您正在訪問會話變量，而不是您的請求參數。

可以使用

request.getParameter("which") 

Answer 2

訪問他們，如果我理解你的問題，你應該使用ServletRequest.getParameter(String)，

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

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

}