PHP + cURL - 输出比预期的要早？(PHP + cURL - output is older than expected?)

 我一直想弄清楚两天为什么这不起作用。 基本上我正在使用TradeMe的API，他们在这里有一个.json文件： 
 
 链接1： http ： //api.trademe.co.nz/v1/Listings/Latest.json 
 
 而不是耗尽API速率限制，我认为好吧......我只会为我的网络服务器编写一个脚本来抓取这个文件并将其返回给我（我当然必须在本地缓存它但我还不完全到了那里）。 我们只是说我的抓取器URL是这样的： 
 
 链接2：http：// {MY URL} /trademe/fetcher.php?url=http://api.trademe.co.nz/v1/Listings/Latest.json 
 
 事情是......链接2的cURL返回给我的不是链接1返回给我的东西！ 每次我运行我的脚本（链接2）时，它总是给我一个旧版本的链接1的JSON文件（我知道它是一个旧版本，因为我查看了JSON文件中的ListingId数字）。 有时我运行链接2，它给了我一个更新的JSON，然后当我刷新脚本时，它再次给我更旧的JSON！ （请注意，如果我直接在Chrome中访问链接1，它总会向我提供最新的JSON文件。我的脚本有问题吗？） 
 
 这是我的脚本： 
 
<?php

set_time_limit(3600);

header("Content-Type: application/json");
header("Expires: on, 01 Jan 1970 00:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

$ch = curl_init();
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/534.51.22 (KHTML, like Gecko) Version/5.1.1 Safari/534.51.22');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 0);
curl_setopt($ch, CURLOPT_FAILONERROR, false);
curl_setopt($ch, CURLOPT_URL, $_GET['url']);
$contents = curl_exec($ch);
curl_close($ch);

echo $contents;
?>
 
 我基本上是通过jQuery的$ .getJSON来调用这个脚本。 我甚至把无缓存头文件放在我的index.php中，并放入$ .ajaxSetup（{cache：false}）; 但没有运气。 
 
 有任何想法吗？ 
 
 （这可能会有所启发，但我还没有发现任何东西： http ： //developer.trademe.co.nz/api-overview/ ） 
 
 干杯 

I've been trying to figure out for two days now why this isn't working. Basically I'm playing around with TradeMe's API and they have a .json file here:
 
Link 1: http://api.trademe.co.nz/v1/Listings/Latest.json
 
Rather than exhaust the API rate limit I thought ok... I'll just write a script for my web server that grabs this file and returns it to me (I'll have to cache it locally of course but I haven't quite gotten there yet). Let's just say my fetcher URL is this:
 
Link 2: http://{MY URL}/trademe/fetcher.php?url=http://api.trademe.co.nz/v1/Listings/Latest.json
 
The thing is... what cURL returns me for link 2 is NOT what link 1 returns me! Every time I run my script (link 2) it always gives me an older version of link 1's JSON file (I know it's an older version because I look at the ListingId numbers in the JSON file). Sometimes I run link 2 and it gives me a newer JSON and then when I refresh the script it gives me the older JSON again! (Note that if I access link 1 directly in Chrome it always gives me the latest JSON file. There is something wrong with my script?)
 
Here's my script:
 
<?php

set_time_limit(3600);

header("Content-Type: application/json");
header("Expires: on, 01 Jan 1970 00:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

$ch = curl_init();
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/534.51.22 (KHTML, like Gecko) Version/5.1.1 Safari/534.51.22');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 0);
curl_setopt($ch, CURLOPT_FAILONERROR, false);
curl_setopt($ch, CURLOPT_URL, $_GET['url']);
$contents = curl_exec($ch);
curl_close($ch);

echo $contents;
?>
 
I'm basically invoking this script through jQuery's $.getJSON. I've even put the no cache headers in my index.php and also put in $.ajaxSetup({ cache: false }); but no luck.
 
Any ideas?
 
(This may shed some light but I've yet to find anything: http://developer.trademe.co.nz/api-overview/)
 
Cheers

原文：https://stackoverflow.com/questions/13794528