파라미터값 모를때

<%@ page contentType="text/html; charset=euc-kr"%>
<%@page import!="java.util.*" %>

<%
request.setCharacterEncoding("euc-kr");

String url = "";
    Enumeration e = request.getParameterNames();  
    while(e.hasMoreElements()){
     String name = (String)e.nextElement();
      if(request.getParameter(name)!=null){
        url += name + "=" + request.getParameter(name) + "&";
      }else{
        url += name + "=" + "" + "&";
      }
    }
out.println(url);   
 %>