有没有办法只在一个网页上缓存图像?

时间:2016-06-21 16:07:11

标签: caching meta-tags

我想仅在我网站上的特定页面上缓存图像。

非缓存所有图像非常重要,所以我想一次做1页。

我可以使用META TAGS或PHP或其他方法吗?

1 个答案:

答案 0 :(得分:1)

此代码应该有效。

<?php
//Caching

//get the last-modified-date of this very file
$lastModified=filemtime(__FILE__);
//get a unique hash of this file (etag)
$etagFile = md5_file(__FILE__);
//get the HTTP_IF_MODIFIED_SINCE header if set
$ifModifiedSince=(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? $_SERVER['HTTP_IF_MODIFIED_SINCE'] : false);
//get the HTTP_IF_NONE_MATCH header if set (etag: unique file hash)
$etagHeader=(isset($_SERVER['HTTP_IF_NONE_MATCH']) ? trim($_SERVER['HTTP_IF_NONE_MATCH']) : false);

//set last-modified header
header("Last-Modified: ".gmdate("D, d M Y H:i:s", $lastModified)." GMT");
//set etag-header
header("Etag: $etagFile");
//make sure caching is turned on
header('Cache-Control: public');

//check if page has changed. If not, send 304 and exit
if (@strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])==$lastModified || $etagHeader == $etagFile)
{
       header("HTTP/1.1 304 Not Modified");
       exit;
}

//your normal code
//echo "This page was last modified: ".date("d.m.Y H:i:s",time());

//END OF Caching
?>