HTTP标头ETag未发送回服务器

Question

在提供以编程方式生成的javascript文件时，我在服务器和浏览器的响应标头中提供ETag。 在对该相同javascript文件的后续请求中，浏览器 ETag不会在请求标题 中提供。

我已经在Chrome和IE中尝试了这一点，同样的结果位于原始请求和后续请求的请求和响应标题下方。

原始请求标题

GET /v11/RUNTIME_SUPPORT.GetGlobalFormResources.aspx HTTP/1.1
Host: 101.152.80.163
Connection: keep-alive
Cache-Control: max-age=0
Accept: */*
X-FirePHP-Version: 0.0.6
User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.66 Safari/537.36
Referer: http://101.152.80.163/v11/Web_Support.Html.aspx
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8,ro;q=0.6,es;q=0.4
Cookie: StaraspxOpenTabsCount=0; ASP.NET_SessionId=jpdkfccaf0zttoxyvys53ac3; STARaspx_SessionId=1006606D-F415-4AE5-AA4C-847625EB2BAE
If-None-Match: 0.0.459

原始回复标题

HTTP/1.1 200 OK
Cache-Control: public, max-age=604800
Content-Type: application/javascript; charset=utf-8
Content-Encoding: gzip
ETag: 0.0.459,0.0.0,0.00
Vary: Accept-Encoding
Server: Microsoft-IIS/8.5
ItemType: FORMS
Digest: e0d3a2bdee4c0a48bc4f61bb744755c21c1d6c19
X-Powered-By: ASP.NET
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1
X-Content-Type-Options: nosniff
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET,PUT,POST,DELETE,OPTIONS
Access-Control-Allow-Headers: callfrom, content-type, runtimecalltype
Access-Control-Allow-Credentials: true
Date: Tue, 12 Apr 2016 11:46:06 GMT
Content-Length: 31763

后续请求标题

GET /v11/RUNTIME_SUPPORT.GetGlobalFormResources.aspx HTTP/1.1
Host: 101.152.80.163
Connection: keep-alive
Cache-Control: max-age=0
Accept: */*
X-FirePHP-Version: 0.0.6
User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.66 Safari/537.36
Referer: http://101.152.80.163/v11/Web_Support.Html.aspx
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8,ro;q=0.6,es;q=0.4
Cookie: StaraspxOpenTabsCount=0; ASP.NET_SessionId=jpdkfccaf0zttoxyvys53ac3; STARaspx_SessionId=1006606D-F415-4AE5-AA4C-847625EB2BAE
If-None-Match: 0.0.459

后续响应标题

HTTP/1.1 200 OK
Cache-Control: public, max-age=604800
Content-Type: application/javascript; charset=utf-8
Content-Encoding: gzip
ETag: 0.0.459,0.0.0,0.00
Vary: Accept-Encoding
Server: Microsoft-IIS/8.5
ItemType: FORMS
Digest: e0d3a2bdee4c0a48bc4f61bb744755c21c1d6c19
X-Powered-By: ASP.NET
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1
X-Content-Type-Options: nosniff
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET,PUT,POST,DELETE,OPTIONS
Access-Control-Allow-Headers: callfrom, content-type, runtimecalltype
Access-Control-Allow-Credentials: true
Date: Tue, 12 Apr 2016 11:46:48 GMT
Content-Length: 31763