Chrome浏览器从磁盘缓存返回http 200。但是我在响应头中没有找到“过期”或“缓存控制”？据我所知，应该有响应过期或cahce控制，然后资源可能来自缓存。为什么从磁盘缓存中返回http 200代码，既不过期也不响应头缓存控制？
Access-Control-Allow-Credentials:true Access-Control-Allow-Headers:DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type Access-Control-Allow-Methods:GET, POST, OPTIONS Access-Control-Allow-Origin:* Content-Encoding:gzip Content-Security-Policy-Report:default-src 'self' 'unsafe-eval'; img-src *; child-src 'self' *; connect-src 'self' * wss:; script-src 'self' 'unsafe-eval' 'unsafe-inline' *.modules.yaas.io js.stripe.com *.sapjam.com *.hanatrial.ondemand.com; style-src 'self' 'unsafe-inline' sapui5.hana.ondemand.com data: *.yaas.io api.eu.yaas.io api.us.yaas.io s3.amazonaws.com accounts.sap.com Content-Type:application/x-javascript Date:Fri, 14 Jul 2017 03:23:27 GMT Etag:W/"59675378-8db28" Last-Modified:Thu, 13 Jul 2017 11:03:20 GMT Server:nginx/1.11.13 Vary:Accept-Encoding X-Frame-Options:SAMEORIGIN X-Vcap-Request-Id:34e06156-0a53-49d8-6e1e-f0ad50ac46bb X-Xss-Protection:1; mode=block
Please see the http response header screen shot
当我使用Firefox萤火做调查。有一个缓存部分表示过期日期，但响应头中没有过期日期。
HTTPS：/ /www.greenbytes.de/tech/webdav/rfc7234.html#heuristic.freshness –
感谢您的信息。 – user3157837