request.getParameterNames的应用

JSP中request.getParameterNames 可以获得客户端的信息;
try {
     java.util.Enumeration params = request.getParameterNames();
            while (params.hasMoreElements()) {
                String key = (String) params.nextElement();//取名
                if (key.indexOf("sy_") < 0) {
                    continue;
                }
//        log.info(key);
String value = request.getParameter(key);//取出值来
System.out.println("value:"+value);