{"id":503,"date":"2016-05-19T11:47:54","date_gmt":"2016-05-19T11:47:54","guid":{"rendered":"285e19f20beded7d215102b49d5c09a0"},"modified":"2016-05-19T11:47:54","modified_gmt":"2016-05-19T11:47:54","slug":"","status":"publish","type":"post","link":"https:\/\/www.xiaobo.li\/notes\/archives\/503","title":{"rendered":"Expires,Cache-Control,Last-Modified,ETag"},"content":{"rendered":"

<\/p>\n

1.Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09HTTP\u5934\u4fe1\u606f<\/strong>Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09 \u5c5e\u6027\u662fHTTP\u63a7\u5236\u7f13\u5b58\u7684\u57fa\u672c\u624b\u6bb5\uff0c\u8fd9\u4e2a\u5c5e\u6027\u544a\u8bc9\u7f13\u5b58\u5668\uff1a\u76f8\u5173\u526f\u672c\u5728\u591a\u957f\u65f6\u95f4\u5185\u662f\u65b0\u9c9c\u7684\u3002\u8fc7\u4e86\u8fd9\u4e2a\u65f6\u95f4\uff0c\u7f13\u5b58\u5668\u5c31\u4f1a\u5411\u6e90\u670d\u52a1\u5668\u53d1\u9001\u8bf7\u6c42\uff0c\u68c0\u67e5\u6587\u6863\u662f\u5426\u88ab\u4fee \u6539\u3002\u51e0\u4e4e\u6240\u6709\u7684\u7f13\u5b58\u670d\u52a1\u5668\u90fd\u652f\u6301Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09\u5c5e\u6027\uff1b<\/p>\n

\u5927\u90e8\u5206Web\u670d\u52a1\u5668\u652f\u6301\u4f60\u7528\u51e0\u79cd\u65b9\u5f0f\u8bbe\u7f6eExpires\u5c5e\u6027\uff1b\u4e00\u822c \u7684\uff1a\u53ef\u4ee5\u8bbe\u8ba1\u4e00\u4e2a\u7edd\u5bf9\u65f6\u95f4\u95f4\u9694\uff1a\u57fa\u4e8e\u5ba2\u6237\u6700\u540e\u67e5\u770b\u526f\u672c\u7684\u65f6\u95f4\uff08\u6700\u540e\u8bbf\u95ee\u65f6\u95f4\uff09\u6216\u8005\u6839\u636e\u670d\u52a1\u5668\u4e0a\u6587\u6863\u6700\u540e\u88ab\u4fee\u6539\u7684\u65f6\u95f4\uff1b<\/p>\n

Expires<\/p>\n

\u5934\u4fe1\u606f\uff1a\u5bf9\u4e8e\u8bbe\u7f6e\u9759\u6001\u56fe\u7247\u6587\u4ef6\uff08\u4f8b\u5982\u5bfc\u822a\u680f\u548c\u56fe\u7247\u6309\u94ae\uff09\u53ef\u7f13\u5b58\u7279\u522b\u6709\u7528\uff1b\u56e0\u4e3a\u8fd9\u4e9b\u56fe\u7247\u4fee\u6539\u5f88\u5c11\uff0c\u4f60\u53ef\u4ee5\u7ed9\u5b83\u4eec\u8bbe\u7f6e\u4e00\u4e2a\u7279\u522b\u957f\u7684\u8fc7\u671f\u65f6\u95f4\uff0c\u8fd9\u4f1a\u4f7f\u4f60\u7684\u7f51\u7ad9\u5bf9
\n \u7528\u6237\u53d8\u5f97\u76f8\u5e94\u975e\u5e38\u5feb\uff1b\u4ed6\u4eec\u5bf9\u4e8e\u63a7\u5236\u6709\u89c4\u5f8b\u6539\u53d8\u7684\u7f51\u9875\u4e5f\u5f88\u6709\u7528\uff0c\u4f8b\u5982\uff1a\u4f60\u6bcf\u5929\u65e9\u4e0a6\u70b9\u66f4\u65b0\u65b0\u95fb\u9875\uff0c\u4f60\u53ef\u4ee5\u8bbe\u7f6e\u526f\u672c\u7684\u8fc7\u671f\u65f6\u95f4\u4e5f\u662f\u8fd9\u4e2a\u65f6\u95f4\uff0c\u8fd9\u6837\u7f13\u5b58
\n\u670d\u52a1\u5668\u5c31\u77e5\u9053\u4ec0\u4e48\u65f6\u5019\u53bb\u53d6\u4e00\u4e2a\u66f4\u65b0\u7248\u672c\uff0c\u800c\u4e0d\u5fc5\u8ba9\u7528\u6237\u53bb\u6309\u6d4f\u89c8\u5668\u7684\u201c\u5237\u65b0\u201d\u6309\u94ae\u3002<\/p>\n

\u8fc7\u671f\u65f6\u95f4\u5934\u4fe1\u606f\u5c5e\u6027\u503c\u53ea\u80fd\u662fHTTP\u683c\u5f0f\u7684\u65e5\u671f\u65f6\u95f4\uff0c\u5176\u4ed6<\/strong><\/u><\/a>\u7684\u90fd\u4f1a\u88ab\u89e3\u6790\u6210\u5f53\u524d\u65f6\u95f4\u201c\u4e4b\u524d\u201d\uff0c\u526f\u672c\u4f1a\u8fc7\u671f\uff0c\u8bb0\u4f4f\uff1aHTTP\u7684\u65e5\u671f\u65f6\u95f4\u5fc5\u987b\u662f\u683c\u6797\u5a01\u6cbb\u65f6 \u95f4\uff08GMT\uff09\uff0c\u800c\u4e0d\u662f\u672c\u5730\u65f6\u95f4\u3002\u4e3e\u4f8b\uff1a

\nExpires: Fri, 30 Oct 1998 14:19:41<\/p>\n

\u6240\u4ee5\u4f7f\u7528\u8fc7\u671f\u65f6\u95f4\u5c5e\u6027\u4e00\u5b9a\u8981\u786e\u8ba4\u4f60\u7684Web\u670d\u52a1\u5668\u65f6\u95f4\u8bbe\u7f6e\u6b63\u786e\uff0c\u4e00\u4e2a\u9014\u5f84\u662f\u901a\u8fc7\u7f51\u7edc\u65f6\u95f4\u540c\u6b65\u534f\u8bae\uff08Network Time Protocol NTP\uff09\uff0c\u548c\u4f60\u7684\u7cfb\u7edf\u7ba1\u7406\u5458\u90a3\u91cc\u4f60\u53ef\u4ee5\u4e86\u89e3\u66f4\u591a\u7ec6\u8282\u3002<\/p>\n

\u867d\u7136\u8fc7\u671f\u65f6\u95f4\u5c5e\u6027\u975e\u5e38\u6709\u7528\uff0c\u4f46\u662f\u5b83\u8fd8\u662f\u6709\u4e9b\u5c40\u9650\uff0c\u9996\u5148\uff1a\u662f\u7275\u626f\u5230\u4e86\u65e5\u671f\uff0c\u8fd9\u6837Web\u670d\u52a1\u5668\u7684\u65f6\u95f4\u548c\u7f13\u5b58\u670d\u52a1\u5668\u7684\u65f6\u95f4\u5fc5\u987b\u662f\u540c\u6b65\u7684\uff0c\u5982\u679c\u6709\u4e9b\u4e0d\u540c\u6b65\uff0c \u8981\u4e48\u662f\u5e94\u8be5\u7f13\u5b58\u7684\u5185\u5bb9\u63d0\u524d\u8fc7\u671f\u4e86\uff0c\u8981\u4e48\u662f\u8fc7\u671f\u7ed3\u679c\u6ca1\u53ca\u65f6\u66f4\u65b0\u3002<\/p>\n

\u8fd8\u6709\u4e00\u4e2a\u8fc7\u671f\u65f6\u95f4\u8bbe\u7f6e\u7684\u95ee\u9898\u4e5f\u4e0d\u5bb9\u5ffd\u89c6\uff1a\u5982\u679c\u4f60\u8bbe\u7f6e\u7684\u8fc7\u671f\u65f6\u95f4\u662f\u4e00\u4e2a\u56fa\u5b9a\u7684\u65f6\u95f4\uff0c\u5982\u679c\u4f60\u8fd4\u56de\u5185\u5bb9\u7684\u65f6\u5019\u53c8\u6ca1\u6709\u8fde\u5e26\u66f4\u65b0\u4e0b\u6b21\u8fc7\u671f\u7684\u65f6\u95f4\uff0c\u90a3\u4e48\u4e4b\u540e\u6240\u6709 \u8bbf\u95ee\u8bf7\u6c42\u90fd\u4f1a\u88ab\u53d1\u9001\u7ed9\u6e90Web\u670d\u52a1\u5668\uff0c\u53cd\u800c\u589e\u52a0\u4e86\u8d1f\u8f7d\u548c\u54cd\u5e94\u65f6\u95f4\uff1b<\/p>\n

2.Cache-Control\uff08\u7f13\u5b58\u63a7\u5236\uff09 HTTP\u5934\u4fe1\u606f<\/strong><\/h3>\n

HTTP 1.1\u4ecb\u7ecd\u4e86\u53e6\u5916\u4e00\u7ec4\u5934\u4fe1\u606f\u5c5e\u6027\uff1aCache-Control\u54cd\u5e94\u5934\u4fe1\u606f\uff0c\u8ba9\u7f51\u7ad9\u7684\u53d1\u5e03\u8005\u53ef\u4ee5\u66f4\u5168\u9762\u7684\u63a7\u5236\u4ed6\u4eec\u7684\u5185\u5bb9\uff0c\u5e76\u5b9a\u4f4d\u8fc7\u671f\u65f6\u95f4\u7684\u9650\u5236\u3002

\n\u6709 \u7528\u7684 Cache-Control\u54cd\u5e94\u5934\u4fe1\u606f\u5305\u62ec\uff1a<\/p>\n

max-age=[\u79d2] \u2014 \u6267\u884c\u7f13\u5b58\u88ab\u8ba4\u4e3a\u662f\u6700\u65b0\u7684\u6700\u957f\u65f6\u95f4\u3002\u7c7b\u4f3c\u4e8e\u8fc7\u671f\u65f6\u95f4\uff0c\u8fd9\u4e2a\u53c2\u6570\u662f\u57fa\u4e8e\u8bf7\u6c42\u65f6\u95f4\u7684\u76f8\u5bf9\u65f6\u95f4\u95f4\u9694\uff0c\u800c\u4e0d\u662f\u7edd\u5bf9\u8fc7\u671f\u65f6\u95f4\uff0c[\u79d2]\u662f\u4e00\u4e2a\u6570\u5b57\uff0c\u5355\u4f4d\u662f\u79d2\uff1a\u4ece\u8bf7\u6c42\u65f6\u95f4 \u5f00\u59cb\u5230\u8fc7\u671f\u65f6\u95f4\u4e4b\u95f4\u7684\u79d2\u6570\u3002

\ns-maxage=[\u79d2] \u2014 \u7c7b\u4f3c\u4e8emax-age\u5c5e\u6027\uff0c\u9664\u4e86\u4ed6\u5e94\u7528\u4e8e\u5171\u4eab\uff08\u5982\uff1a\u4ee3\u7406\u670d\u52a1\u5668\uff09\u7f13\u5b58

\npublic \u2014 \u6807\u8bb0\u8ba4\u8bc1\u5185\u5bb9\u4e5f\u53ef\u4ee5\u88ab\u7f13\u5b58\uff0c\u4e00\u822c\u6765\u8bf4\uff1a \u7ecf\u8fc7HTTP\u8ba4\u8bc1\u624d\u80fd\u8bbf\u95ee\u7684\u5185\u5bb9\uff0c\u8f93\u51fa\u662f\u81ea\u52a8\u4e0d\u53ef\u4ee5\u7f13\u5b58\u7684\uff1b

\nno-cache \u2014 \u5f3a\u5236\u6bcf\u6b21\u8bf7\u6c42\u76f4\u63a5\u53d1\u9001\u7ed9\u6e90\u670d\u52a1\u5668\uff0c\u800c\u4e0d\u7ecf\u8fc7\u672c\u5730\u7f13\u5b58\u7248\u672c\u7684\u6821\u9a8c\u3002\u8fd9\u5bf9\u4e8e\u9700\u8981\u786e\u8ba4\u8ba4\u8bc1\u5e94\u7528\u5f88\u6709\u7528\uff08\u53ef\u4ee5\u548cpublic\u7ed3\u5408\u4f7f\u7528\uff09\uff0c\u6216\u8005\u4e25\u683c\u8981\u6c42\u4f7f\u7528\u6700\u65b0\u6570\u636e \u7684\u5e94\u7528\uff08\u4e0d\u60dc\u727a\u7272\u4f7f\u7528\u7f13\u5b58\u7684\u6240\u6709\u597d\u5904\uff09\uff1b

\nno-store \u2014 \u5f3a\u5236\u7f13\u5b58\u5728\u4efb\u4f55\u60c5\u51b5\u4e0b\u90fd\u4e0d\u8981\u4fdd\u7559\u4efb\u4f55\u526f\u672c

\nmust-revalidate \u2014 \u544a\u8bc9\u7f13\u5b58\u5fc5\u987b\u9075\u5faa\u6240\u6709\u4f60\u7ed9\u4e88\u526f\u672c\u7684\u65b0\u9c9c\u5ea6\u7684\uff0cHTTP\u5141\u8bb8\u7f13\u5b58\u5728\u67d0\u4e9b\u7279\u5b9a\u60c5\u51b5\u4e0b\u8fd4\u56de\u8fc7\u671f\u6570\u636e\uff0c\u6307\u5b9a\u4e86\u8fd9\u4e2a\u5c5e\u6027\uff0c\u4f60\u9ad8\u901f\u7f13\u5b58\uff0c\u4f60\u5e0c\u671b\u4e25\u683c\u7684\u9075\u5faa\u4f60\u7684\u89c4\u5219\u3002

\nproxy-revalidate \u2014 \u548c must-revalidate\u7c7b\u4f3c\uff0c\u9664\u4e86\u4ed6\u53ea\u5bf9\u7f13\u5b58\u4ee3\u7406\u670d\u52a1\u5668\u8d77\u4f5c\u7528

\n\u4e3e\u4f8b:

\nCache-Control: max-age=3600, must-revalidate<\/p>\n

\u7ed9
\n\u9759\u6001\u8d44\u6e90(HTML\u6587\u4ef6\uff0c\u56fe\u7247\u6587\u4ef6\u7b49\uff09\u7684Repsone\u52a0\u4e0aExpires\/Cache-Control Header\u662f\u5f88\u6709\u6548\u7684\u4e00\u62db\u3002\u5982\u679cHTTP
\nResponse\u4e2d\u6709Expires\u8fd9\u6837\u7684Header\u7684\u8bdd\uff0c\u6d4f\u89c8\u5668\u4f1aCache\u8fd9\u4e2a\u8d44\u6e90\uff0c\u7406\u60f3\u72b6\u51b5\u4e0b\uff08\u6ce8\u610f\uff0c\u53ea\u662f\u7406\u60f3\u72b6\u51b5\uff09\uff0c\u5728Expire
\nDate\u4e4b\u524d\uff0c\u4e0d\u4f1a\u518d\u53d1HTTP\u8bf7\u6c42\u7ed9Server\u8981\u8fd9\u4e2a\u8d44\u6e90\uff0c\u4e0d\u8fc7Expires\u7684\u503c\u53ea\u80fd\u662f\u4e00\u4e2a\u56fa\u5b9a\u65e5\u671f\uff0c\u6bd4\u5982\u201cThu 27 Nov 2008
\n07:00:00
\nGMT\u201d\uff0c\u4e0d\u80fd\u662f\u4e00\u4e2a\u7c7b\u4f3c\u201c\u4ece\u73b0\u5728\u5f00\u59cb\u4e4b\u540e10\u5e74\u201d\u8fd9\u6837\u4e00\u4e2a\u968f\u673a\u6d6e\u52a8\u7684\u503c\uff0c\u5982\u679c\u8981\u8fd9\u6837\u7684\u6548\u679c\uff0c\u53ef\u4ee5\u7528Cache-Control\u8fd9\u6837\u7684Header\uff0c\u5982\u679c
\n HTTP Response\u4e2d\u6709\u8fd9\u6837\u7684Header:\u201cCache-Control: max-age =
\n100\u201d\uff0c\u8868\u793a\u8fd9\u4e2a\u8d44\u6e90\u5728cache\u4e2d\u7684\u6700\u5927\u5bff\u547d\u662f100\u79d2\u3002\u4e00\u822c\u8bf4\u6765\u8fd9\u79cd\u9759\u6001\u6587\u4ef6\u6c38\u8fdc\u4e0d\u5e94\u8be5\u8fc7\u671f\uff0c\u5982\u679c\u771f\u7684\u8981\u7ed9\u8fd9\u4e2aCache\u52a0\u4e0a\u4e00\u4e2a\u671f\u9650\uff0c\u90a3\u6211\u5e0c\u671b\u662f
\n \u2014\u2014\u4e00\u4e07\u5e74\uff0c\u201cCache-Control: max-age = 315360000000\u201d<\/p>\n

\u5176\u5b9e\u5c31\u5e94\u8be5\u7ed9Expires\u8bbe\u4e00\u4e2a\u6c38\u8fdc\u4e0d\u4f1a\u8fc7\u671f\u7684\u65f6\u95f4\uff0c\u6bd4\u5982\u4f60\u73b0\u5728\u6709\u4e00\u4e2a\u6587\u4ef6\u53eblogo.gif\uff0c\u9700\u8981\u7528\u4e00\u4e2a\u65b0\u7684logo\u7684\u65f6\u5019\uff0c\u4f60\u4e0d\u8981\u53bb \u8986\u76d6\u539f\u6765\u7684\u6587\u4ef6\uff0c\u800c\u628a\u65b0\u7684logo\u5b58\u6210logo_v2.gif\uff0c\u8ba9\u76f8\u5173\u7f51\u9875\u5f15\u7528\u65b0\u7684logo_v2.gif\uff0c\u8fd9\u6837\u53ef\u4ee5\u8ba9\u65b0\u8001\u7f51\u9875\u540c\u65f6\u5de5\u4f5c<\/strong><\/u><\/a>\uff0c\u5b9e\u5728\u72af\u4e0d\u4e0a\u4e3a\u4e86 \u8282\u7701\u5b58\u50a8\u7a7a\u95f4\u8986\u76d6\u539f\u6709\u6587\u4ef6\u3002<\/p>\n

\u5bf9Apache\u670d\u52a1\u5668\uff0c\u4f7f\u7528mod_expires\uff0c\u5728httpd.conf\u6216\u8005.htaccess\u4e2d\u52a0\u4e0a<\/p>\n

<FilesMatch \u201c\\\\.(ico|gif|jpg|html)$\u201d>ExpiresDefault<\/a> \u201caccess plus 10 years\u201d<\/FileMatch><\/p>\n

3.Last-Modified\/If-Modified-Since<\/strong><\/h3>\n

\u6709\u4e9b\u6570\u636e\u968f\u65f6\u90fd\u5728\u53d8\u5316\u3002 CNN.com \u7684\u4e3b\u9875\u7ecf\u5e38\u51e0\u5206\u949f\u5c31\u66f4\u65b0\u3002\u53e6\u4e00\u65b9\u9762\uff0cGoogle<\/strong><\/u><\/a>.com \u7684\u4e3b\u9875\u51e0\u4e2a\u661f\u671f\u624d\u66f4\u65b0\u4e00\u6b21 (\u5f53\u4ed6\u4eec\u4e0a\u4f20\u7279\u6b8a\u7684\u5047\u65e5 logo\uff0c\u6216\u4e3a\u4e00\u4e2a\u65b0\u670d\u52a1\u4f5c\u5e7f\u544a\u65f6)\u3002 Web \u670d\u52a1\u662f\u4e0d\u53d8\u7684\uff1a\u901a\u5e38\u670d\u52a1\u5668\u77e5\u9053\u4f60\u6240\u8bf7\u6c42\u7684\u6570\u636e\u7684\u6700\u540e\u4fee\u6539\u65f6\u95f4\uff0c\u5e76\u4e14 HTTP \u4e3a\u670d\u52a1\u5668\u63d0\u4f9b\u4e86\u4e00\u79cd\u5c06\u6700\u8fd1\u4fee\u6539\u6570\u636e\u8fde\u540c\u4f60\u8bf7\u6c42\u7684\u6570\u636e\u4e00\u540c\u53d1\u9001\u7684\u65b9\u6cd5\u3002<\/p>\n

\u5982
\n\u679c\u4f60\u7b2c\u4e8c\u6b21 (\u6216\u7b2c\u4e09\u6b21\uff0c\u6216\u7b2c\u56db\u6b21) \u8bf7\u6c42\u76f8\u540c\u7684\u6570\u636e\uff0c\u4f60\u53ef\u4ee5\u544a\u8bc9\u670d\u52a1\u5668\u4f60\u4e0a\u4e00\u6b21\u83b7\u5f97\u7684\u6700\u540e\u4fee\u6539\u65e5\u671f\uff1a\u5728\u4f60\u7684\u8bf7\u6c42\u4e2d\u53d1\u9001\u4e00\u4e2a
\nIf-Modified-Since \u5934\u4fe1\u606f\uff0c\u5b83\u5305\u542b\u4e86\u4e0a\u4e00\u6b21\u4ece\u670d\u52a1\u5668\u8fde\u540c\u6570\u636e\u6240\u83b7\u5f97\u7684\u65e5\u671f\u3002\u5982\u679c\u6570\u636e\u4ece\u90a3\u65f6\u8d77\u6ca1\u6709\u6539\u53d8\uff0c\u670d\u52a1\u5668\u5c06\u8fd4\u56de\u4e00\u4e2a\u7279\u6b8a\u7684
\nHTTP \u72b6\u6001\u4ee3\u7801 304\uff0c\u8fd9\u610f\u5473\u7740 \u201c\u4ece\u4e0a\u4e00\u6b21\u8bf7\u6c42\u540e\u8fd9\u4e2a\u6570\u636e\u6ca1\u6709\u6539\u53d8\u201d\u3002\u8fd9\u4e00\u70b9\u6709\u4f55\u8fdb\u6b65\u5462\uff1f\u5f53\u670d\u52a1\u5668\u53d1\u9001\u72b6\u6001\u7f16\u7801 304
\n\u65f6\uff0c\u4e0d\u518d\u91cd\u65b0\u53d1\u9001\u6570\u636e\u3002\u60a8\u4ec5\u4ec5\u83b7\u5f97\u4e86\u8fd9\u4e2a\u72b6\u6001\u4ee3\u7801\u3002\u6240\u4ee5\u5f53\u6570\u636e\u6ca1\u6709\u66f4\u65b0\u65f6\uff0c\u4f60\u4e0d\u9700\u8981\u4e00\u6b21\u53c8\u4e00\u6b21\u5730\u4e0b\u8f7d\u76f8\u540c\u7684\u6570\u636e\uff1b\u670d\u52a1\u5668\u5047\u5b9a\u4f60\u6709\u672c\u5730\u7684\u7f13\u5b58\u6570\u636e\u3002<\/p>\n

\u6240
\n\u6709\u73b0\u4ee3\u7684\u6d4f\u89c8\u5668\u90fd\u652f\u6301\u6700\u8fd1\u4fee\u6539 (last-modified)
\n\u7684\u6570\u636e\u68c0\u67e5\u3002\u5982\u679c\u4f60\u66fe\u7ecf\u8bbf\u95ee\u8fc7\u67d0\u9875\uff0c\u4e00\u5929\u540e\u91cd\u65b0\u8bbf\u95ee\u76f8\u540c\u7684\u9875\u65f6\u53d1\u73b0\u5b83\u6ca1\u6709\u53d8\u5316\uff0c\u5e76\u5947\u602a\u7b2c\u4e8c\u6b21\u8bbf\u95ee\u65f6\u9875\u9762\u52a0\u8f7d\u5f97\u5982\u6b64\u4e4b\u5feb\u2014\u2014\u8fd9\u5c31\u662f\u539f\u56e0\u6240\u5728\u3002\u4f60\u7684\u6d4f\u89c8\u5668\u9996\u6b21
\n \u8bbf\u95ee\u65f6\u4f1a\u5728\u672c\u5730\u7f13\u5b58\u9875\u9762\u5185\u5bb9\uff0c\u5f53\u4f60\u7b2c\u4e8c\u6b21\u8bbf\u95ee\uff0c\u6d4f\u89c8\u5668\u81ea\u52a8\u53d1\u9001\u9996\u6b21\u8bbf\u95ee\u65f6\u4ece\u670d\u52a1\u5668\u83b7\u5f97\u7684\u6700\u8fd1\u4fee\u6539\u65e5\u671f\u3002\u670d\u52a1\u5668\u7b80\u5355\u5730\u8fd4\u56de 304: Not
\nModified (\u6ca1\u6709\u4fee\u6539)\uff0c\u56e0\u6b64\u6d4f\u89c8\u5668\u5c31\u4f1a\u77e5\u9053\u4ece\u672c\u5730\u7f13\u5b58\u52a0\u8f7d\u9875\u9762\u3002\u5728\u8fd9\u4e00\u70b9\u4e0a\uff0cWeb \u670d\u52a1\u4e5f\u5982\u6b64\u667a\u80fd\u3002<\/p>\n

4. ETag\/If-None-Match<\/strong><\/h3>\n

ETag
\n \u662f\u5b9e\u73b0\u4e0e\u6700\u8fd1\u4fee\u6539\u6570\u636e\u68c0\u67e5\u540c\u6837\u7684\u529f\u80fd\u7684\u53e6\u4e00\u79cd\u65b9\u6cd5\uff1a\u6ca1\u6709\u53d8\u5316\u65f6\u4e0d\u91cd\u65b0\u4e0b\u8f7d\u6570\u636e\u3002\u5176\u5de5\u4f5c\u65b9\u5f0f\u662f\uff1a\u670d\u52a1\u5668\u53d1\u9001\u4f60\u6240\u8bf7\u6c42\u7684\u6570\u636e\u7684\u540c\u65f6\uff0c\u53d1\u9001\u67d0\u79cd\u6570\u636e\u7684
\nhash (\u5728 ETag \u5934\u4fe1\u606f\u4e2d\u7ed9\u51fa)\u3002hash \u7684\u786e\u5b9a\u5b8c\u5168\u53d6\u51b3\u4e8e\u670d\u52a1\u5668\u3002\u5f53\u7b2c\u4e8c\u6b21\u8bf7\u6c42\u76f8\u540c\u7684\u6570\u636e\u65f6\uff0c\u4f60\u9700\u8981\u5728 If-None-Match:
\n\u5934\u4fe1\u606f\u4e2d\u5305\u542b ETag hash\uff0c\u5982\u679c\u6570\u636e\u6ca1\u6709\u6539\u53d8\uff0c\u670d\u52a1\u5668\u5c06\u8fd4\u56de 304 \u72b6\u6001\u4ee3\u7801\u3002\u4e0e\u6700\u8fd1\u4fee\u6539\u6570\u636e\u68c0\u67e5\u76f8\u540c\uff0c\u670d\u52a1\u5668\u4ec5\u4ec5 \u53d1\u9001 304
\n\u72b6\u6001\u4ee3\u7801\uff1b\u7b2c\u4e8c\u6b21\u5c06\u4e0d\u4e3a\u4f60\u53d1\u9001\u76f8\u540c\u7684\u6570\u636e\u3002\u5728\u7b2c\u4e8c\u6b21\u8bf7\u6c42\u65f6\uff0c\u901a\u8fc7\u5305\u542b ETag hash\uff0c\u4f60\u544a\u8bc9\u670d\u52a1\u5668\uff1a\u5982\u679c hash
\n\u4ecd\u65e7\u5339\u914d\u5c31\u6ca1\u6709\u5fc5\u8981\u91cd\u65b0\u53d1\u9001\u76f8\u540c\u7684\u6570\u636e\uff0c\u56e0\u4e3a\u4f60\u8fd8\u6709\u4e0a\u4e00\u6b21\u8bbf\u95ee\u8fc7\u7684\u6570\u636e\u3002<\/p>\n

\u8fd9\u51e0\u4e2ahttp\u5934\u53ef\u4ee5\u4f5c\u4e3ameta\u6807\u7b7e\u53d1\u9001\u5230\u5ba2\u6237\u7aef\uff0c\u4f46\u662f\u9700\u8981\u6ce8\u610f\u7684\u662fHttp\u5934\u4e2d\u7684\u8bbe\u7f6e\u4f18\u5148\u7ea7\u66f4\u9ad8\u4e00\u4e9b\uff0c\u4f8b\u5982\uff1a

\n<meta. http-equiv=\u201dExpires\u201d CONTENT=\u201d Fri, 30 Oct 1998 14:19:41\u2033>

\n<meta. http-equiv=\u201dCache-Control\u201d CONTENT=\u201dno-cache\u201d><\/p>\n

\u603b\u7ed3<\/h2>\n

Expires\/Cache-Control Header\u662f\u63a7\u5236\u6d4f\u89c8\u5668\u662f\u5426\u76f4\u63a5\u4ece\u6d4f\u89c8\u5668\u7f13\u5b58\u53d6\u6570\u636e\u8fd8\u662f\u91cd\u65b0\u53d1\u8bf7\u6c42\u5230\u670d\u52a1\u5668\u53d6\u6570\u636e\u3002\u53ea\u662fCache-Control\u6bd4Expires\u53ef\u4ee5\u63a7\u5236\u7684\u591a\u4e00\u4e9b\uff0c \u800c\u4e14Cache-Control\u4f1a\u91cd\u5199Expires\u7684\u89c4\u5219\u3002<\/p>\n

Last-
\nModified\/If-Modified-Since\u548cETag\/If-None-Match\u662f\u6d4f\u89c8\u5668\u53d1\u9001\u8bf7\u6c42\u5230\u670d\u52a1\u5668\u540e\u5224\u65ad\u6587\u4ef6\u662f\u5426
\n\u5df2\u7ecf\u4fee\u6539\u8fc7\uff0c\u5982\u679c\u6ca1\u6709\u4fee\u6539\u8fc7\u5c31\u53ea\u53d1\u9001\u4e00\u4e2a304\u56de\u7ed9\u6d4f\u89c8\u5668\uff0c\u544a\u8bc9\u6d4f\u89c8\u5668\u76f4\u63a5\u4ece\u81ea\u5df1\u672c\u5730\u7684\u7f13\u5b58\u53d6\u6570\u636e\uff1b\u5982\u679c\u4fee\u6539\u8fc7\u90a3\u5c31\u6574\u4e2a\u6570\u636e\u91cd\u65b0\u53d1\u7ed9\u6d4f\u89c8\u5668\u3002<\/p>\n

\n

\n

\u6765\u6e90\uff1a http:\/\/www.51testing.com\/html\/28\/116228-238337.html<\/p>\n

<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

<\/p>\n

1.Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09HTTP\u5934\u4fe1\u606f<\/strong>Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09 \u5c5e\u6027\u662fHTTP\u63a7\u5236\u7f13\u5b58\u7684\u57fa\u672c\u624b\u6bb5\uff0c\u8fd9\u4e2a\u5c5e\u6027\u544a\u8bc9\u7f13\u5b58\u5668\uff1a\u76f8\u5173\u526f\u672c\u5728\u591a\u957f\u65f6\u95f4\u5185\u662f\u65b0\u9c9c\u7684\u3002\u8fc7\u4e86\u8fd9\u4e2a\u65f6\u95f4\uff0c\u7f13\u5b58\u5668\u5c31\u4f1a\u5411\u6e90\u670d\u52a1\u5668\u53d1\u9001\u8bf7\u6c42\uff0c\u68c0\u67e5\u6587\u6863\u662f\u5426\u88ab\u4fee \u6539\u3002\u51e0\u4e4e\u6240\u6709\u7684\u7f13\u5b58\u670d\u52a1\u5668\u90fd\u652f\u6301Expires\uff08\u8fc7\u671f\u65f6\u95f4\uff09\u5c5e\u6027\uff1b<\/p>\n

\u5927\u90e8\u5206Web\u670d\u52a1\u5668\u652f\u6301\u4f60\u7528\u51e0\u79cd\u65b9\u5f0f\u8bbe\u7f6eExpires\u5c5e\u6027\uff1b\u4e00\u822c \u7684\uff1a\u53ef\u4ee5\u8bbe\u8ba1\u4e00\u4e2a\u7edd\u5bf9\u65f6\u95f4\u95f4\u9694\uff1a\u57fa\u4e8e\u5ba2\u6237\u6700\u540e\u67e5\u770b\u526f\u672c\u7684\u65f6\u95f4\uff08\u6700\u540e\u8bbf\u95ee\u65f6\u95f4\uff09\u6216\u8005\u6839\u636e\u670d\u52a1\u5668\u4e0a\u6587\u6863\u6700\u540e\u88ab\u4fee\u6539\u7684\u65f6\u95f4\uff1b<\/p>\n

Expires<\/p>\n

\u5934\u4fe1\u606f\uff1a\u5bf9\u4e8e\u8bbe\u7f6e\u9759\u6001\u56fe\u7247\u6587\u4ef6\uff08\u4f8b\u5982\u5bfc\u822a\u680f\u548c\u56fe\u7247\u6309\u94ae\uff09\u53ef\u7f13\u5b58\u7279\u522b\u6709\u7528\uff1b\u56e0\u4e3a\u8fd9\u4e9b\u56fe\u7247\u4fee\u6539\u5f88\u5c11\uff0c\u4f60\u53ef\u4ee5\u7ed9\u5b83\u4eec\u8bbe\u7f6e\u4e00\u4e2a\u7279\u522b\u957f\u7684\u8fc7\u671f...<\/p>\n

<\/span> \u7ee7\u7eed\u9605\u8bfb →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[283],"tags":[244,242,245,241,243],"class_list":["post-503","post","type-post","status-publish","format-standard","hentry","category-technologys","tag-Cache-Control","tag-ETag","tag-Expires","tag-Last-Modified"],"_links":{"self":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts\/503","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/comments?post=503"}],"version-history":[{"count":0,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/posts\/503\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/media?parent=503"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/categories?post=503"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xiaobo.li\/notes\/wp-json\/wp\/v2\/tags?post=503"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}