1. The chef said, I should use a normal aspx to solve this task, and write sth, like reponse.write(„accpeti encoding : txt/json“), it is ugly. Please read this atricle from Johnny Code (http://johnnycode.com/2012/07/16/getting-json-from-asp-net-beautiful-good-bad-ugly/). Why it is ugly.

2 by defualt .net response only to POST Request and return XML. as wrapper. You should add the following http header in your request.

Content-Type: application/json; charset=utf-8

An end the chef want to sue handler to solve the URL rewrite problme, show me some code in web.config to define a handler.
I found this article about add handler in web.config (http://www.yongfa365.com/Item/configuration-configSections-SingleTagSectionHandler-DictionarySectionHandler-NameValueSectionHandler.html)