不能在浏览器只使用从先前的Ajax调用缓存？能在、缓存、先前、浏览器

2023-09-10 16:27:17 作者：旧街旧巷等旧人

我试图依靠浏览器缓存举行返回的JSON数据从阿贾克斯jQuery的要求。

I am trying to rely upon the browser cache to hold JSON data returned from AJAX calls in jQuery.

普通浏览器活动依赖于浏览器缓存中所有的时间。例如：JPG和GIF图像不重新获取一个页面重新加载

Normal browser activity relies upon the browser cache all the time. Example: jpg and gif images are not refetched on a page reload.

但是当我尝试使用jQuery的getJSON Ajax调用，我似乎无法避免从服务器获取数据。

But when I try using jQuery getJSON ajax calls, I cannot seem to avoid fetching the data from the server.

我返回头看起来像这样（与萤火虫确认）：

My returned headers look like this (confirmed with firebug):

Transfer-Encoding: chunked
Date: Wed, 05 Aug 2009 02:55:39 GMT
Content-Type: text/plain; charset=ISO-8859-1
Expires: Wed, 05 Aug 2009 03:55:39 GMT
Cache-Control: max-age=3600

然而，页面立即刷新导致相同的请求命中服务器。

Yet an immediate refresh of the page causes identical requests to hit the server.

我已经看到了有关避免缓存行为，这不是我所需要的多个岗位。我已经看到了关于利用缓存多个岗位，但这些似乎都依赖在保存数据的DOM。我想要的东西，表现在重新加载页面，就像缓存图像做的。

I've seen several postings about avoiding caching behavior, which isn't what I need. I've seen several postings about utilizing caching, but those all seem to rely upon saving data in the DOM. I want something that behaves just like cached images do during a page reload.

广东话浏览器刚刚从它自己的高速缓存中获取呢？

Cant the browser just fetch it from it's own cache?

- X - X - X - X更新--x - X - X -

--x--x--x--x UPDATE --x--x--x--

但令我失望的是，一些可敬的人都认为这不仅是可能的。有些人甚至认为，这不应该是（这还是令我感到困惑）。

Much to my disappointment, several respectable folks agree that this isn't just possible. Some even argue that it shouldn't be (which still baffles me).

Stubburn一个错误，我试过如下：

Stubburn to a fault, I tried the following:

我设置了ETag头在所有外发的网页我想缓存（我挑选重新present我请求并只使用了ETag值数据几个选择URL参数）

I set the Etag header on all outgoing pages I want to be cached (I pick a few choice URL arguments that represent the data I'm requesting and just use that for the Etag value)

目前的下一个请求的开始，我只是检查如果 - 无 - 匹配标头请求。如果是这样的话，浏览器不缓存请求像我想要的东西，所以我发了304未修改响应。

At the beginning of the next request, I simply check if the 'If-None-Match' header is in the request. If so, then the browser isn't caching the request like I wanted, so I sent a 304 Not Modified response.

测试显示，Firefox将不缓存我的要求（但我还是能避免我的CGI的获取昂贵的数据部分），而IE6实际上将缓存它（甚至不会尝试从服务器获取回）。

Testing shows that Firefox won't cache my request (but I can still avoid the 'fetch the expensive data' part of my cgi), while IE6 will actually cache it (and wont even attempt fetching back from the server).

这不是一个pretty的答案，但它的工作对我来说，现在（图数据的那些pesty全页面刷新不会这么慢或昂贵了）。

It's not a pretty answer, but it's working for me for now (those pesty full-page refreshes of graph data wont be so slow or expensive now).

（什么？我运行的IE6！妈呀！哦，看松鼠！）

(What? I'm running IE6! OMG! Oh look a squirrel!)

不能在浏览器只使用从先前的Ajax调用缓存？能在、缓存、先前、浏览器

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