Retrieve All Http Request Parms

Enumeration enumeration = req.getParameterNames();
for (; enumeration.hasMoreElements();) {
 String name = (String) enumeration.nextElement();
 if (!name.startsWith("rtn_")) {
         continue;
 }
 String safld = req.getParameter(name);
 String tafld = name.substring(4);
 returnData.add(new ReturnDataField(safld,tafld));
}