[JAVA/JSP] JSP Request 모든변수 뽑기

<%
String query="";
Enumeration enum = request.getParameterNames();
while(enum.hasMoreElements()){ 
    String key=(String)enum.nextElement();
    String value=request.getParameter(key);
    query+="&"+key+"="+value;
}
query="?"+query.substring(1);
out.println(query);
%>