Server sends back page a, plus an ETag for a.
服务器返回页面a，并在给a加上一个ETag。
An ETag is a string that uniquely identifies a specific version of a component.
Etag是一个识别内容版本号的唯一字符串。
The origin server specifies the component's ETag using the ETag response header.
原服务器指定组件的ETag使用，ETag响应标头。
We should now make a change and see if the ETag changes. We add a pet to this owner.
我们现在应该做点修改，看看ETag是否改变了。
Otherwise, we set the ETag response header in preparation for the next client request.
否则，我们设置ETag响应头以便为下一次客户端请求做好准备。
ETAG 012 Guideline for European technical approval of Timber frame and log prefabricated building fits.
ETAG 012欧洲技术标准指南-木材框型支架和原木预制安装建筑套件。
And removing the ETag reduces the size of the HTTP headers in both the response and subsequent requests.
并删除该ETag减少响应和后续请求中的http头的大小。
Client requests page a again, passing along the ETag it got back from the server the last time it made the request.
客户再次请求页面a，并将上次请求时服务器返回的ETag一起传递给服务器。
Because the server generated the ETag in the first place, it can use it later to determine if the page has changed.
因为服务器首先产生ETag，服务器可在稍后使用它来判断页面是否已经被修改。
This is considered good form for server generated content as it caters for clients that don't understand ETag headers.
这被认为是为服务器产生内容的正确形式，因为其迎合了不认识ETag头的客户端。
We are computing the ETag value after the page has been rendered on the server, but before sending it back to the client.
我们是在页面已经被展现在服务器之后计算ETag的，但是在返回客户端之前。
We use the count as the ETag, so when the client sends it back we know if one of the objects behind the page has been modified.
我们使用该计数值作为ETag，这样当客户端将ETag送回时我们就知道页面背后的一个或多个对象是否被修改了。
If you're not taking advantage of the flexible validation model that ETags provide, it's better to just remove the ETag altogether.
如果你不利用ETags提供的灵活验证模型，最好只是完全删除该ETag。
If there is a ETag match, there really is no need to pull in the data for the model as the rendered page will not be sent to the client.
如果有Etag匹配，实际上并不需要再为model装进数据，因为要展现的页面不需要发送回客户端。
First we will use a Servlet 2.3 Filter to apply an ETag generated using an MD5 checksum of the rendered view (a "shallow" ETag implementation).
首先我们将使用Servlet 2.3Filter，利用展现视图(rendered view)的MD 5校验和(checksum)以实现生成ETag的方法(一个“浅显的”ETag实现)。
ETAG 014 Guideline for European technical approval of Plastic anchors for fixing of external thermal insulation composite systems with rendering.
ETAG 014欧洲技术标准指南-用于固定外墙保温复合系统的塑料锚栓。
The first approach we will look at is to create a Servlet Filter that will generate its ETag token based on the content of the page - the "View" in MVC.
我们要考虑的第一种方法是创建一个ServletFilter，它将基于页面(MVC中的“View”)的内容产生其ETag记号。
By default, both Apache and IIS embed data in the ETag that dramatically reduces the odds of the validity test succeeding on web sites with multiple servers.
默认情况下，Apache和IIS都会把数据嵌入ETag中，这会显著减少多服务器间的文件验证冲突。
The second approach uses a more sophisticated method to track changes in the model used by the view to determine ETag validity ( a "deep ETag" implementation).
第二种方法使用更为复杂的方法追踪view中所使用的model，以确定ETag有效性（一个“深入的”ETag实现）。
This is an ideal place to apply our ETag comparison logic so that if we find the data that is used to build a page hasn't changed we can avoid further processing.
这儿是应用我们ETag比较逻辑的理想场所，因此如果我们发现构建一个页面的数据没有发生变化，我们可以避免进一步处理。
We first make sure we are dealing with a GET request (ETag in conjunction with PUT can be used to detect conflicting updates, but that is beyond the scope of this article.).
我们首先确信我们正在处理GET请求(与PUT一起的ETag可以用来检测不一致的更新，但其超出了本文的范围。)
HTTP 1.1 introduced a new kind of validator called the ETag. ETags are unique identifiers that are generated by the server and changed every time the representation does.
HTTP 1.1介绍了另外一个校验参数：ETag，服务器是服务器生成的唯一标识符etag，每次副本的标签都会变化。
One-line include in Perl CGI, Python CGI and PHP scripts automatically handles ETag generation and validation, Content-Length generation and gzip Content-Encoding —correctly.
用于CGI模式运行的Perl/Python/PHP脚本，自动处理ETag生成/校验，Content-Length生成和内容压缩。正确地。
Server examines the ETag and determines that the page hasn't changed since last time the client requested it, so sends back a response of 304 (Not Modified) with an empty body.
服务器检查该ETag，并判断出该页面自上次客户端请求之后还未被修改，直接返回响应304(未修改——NotModified)和一个空的响应体。
The tests included individual cache limits and support for Last-Modified and ETag page headers, and for whether the cache was preserved after turning the device off and back on.
测试包括缓存限制、对网页更新判断和ETag的支持，以及重启后缓存是否保留。
My hope is that this article has provided you with food for thought for your current and future web based projects, and an appreciation for the under utilized ETag response header.
我希望本文已为你当下或将来基于Web的项目提供了精神食粮，并正确评价在底层利用ETag响应头的做法。
My hope is that this article has provided you with food for thought for your current and future web based projects, and an appreciation for the under utilized ETag response header.
我希望本文已为你当下或将来基于Web的项目提供了精神食粮，并正确评价在底层利用ETag响应头的做法。
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