Http请求URL长度限制[通俗易懂]

// https://www.ietf.org/rfc/rfc2616.txt 
3.2.1 General Syntax
	   The HTTP protocol does not place any a priori limit on the length of
   a URI. Servers MUST be able to handle the URI of any resource they
   serve, and SHOULD be able to handle URIs of unbounded length if they
   provide GET-based forms that could generate such URIs. A server
   SHOULD return 414 (Request-URI Too Long) status if a URI is longer
   than the server can handle (see section 10.4.15).

      Note: Servers ought to be cautious about depending on URI lengths
      above 255 bytes, because some older client or proxy
      implementations might not properly support these lengths.

     HTTP协议不对URI的长度作事先的限制，服务器必须能够处理任何他们提供资源的URI，并且应该能够处理无限长度的URIs，这种无效长度的URL可能会在客户端以基于GET方式的请求时产生。如果服务器不能处理太长的URI的时候，服务器应该返回414状态码（此状态码代表Request-URI太长）。

    注:服务器在依赖大于255字节的URI时应谨慎，因为一些旧的客户或代理实现可能不支持这些长度。

协议中未明确对url进行长度限制，但在真正实现中，url的长度还是受到限制的，一是服务器端的限制，二就是浏览器端的限制。