php file_get_contents 报错

昨天在工作中遇到这样一个问题：

PHP Warning:  file_get_contents(http://platform.handsmart.mobi/userplatform/pay/face.php?a=getMoneyAndMsgNum&amp;appid=1&amp;username=3c5122d46b38451731189397098d115b&amp;uid=bda30b0c713e44da6c8e4feb7e78a290&amp;secret=181fa343509968304d51a09e170a4801) [<a href="function.file-get-contents">function.file-get-contents</a>]: failed to open stream: Connection refused in /usr/local/rakoo/userplatform/item/action/fastBuyItemAction.php on line 21

开始一看报错，发现url跟自己写的好像是不一样，所有的&都转义成了&amp;，就固执的定位为你程序编码错误，是系统把url给转义了，所以也就一直在网上找&转义这个问题的解决方案。但最终发现不是url有问题，在url中出现&amp;是正常的，上面那个错误的意思是：file_get_contents无法获取到那个url中的数据流，打开流失败，所以正在的问题应该是那请求响应超时了，所以php报错了。为什么超时呢？这就可能是网络不好了，响应时间超出了php等待时间。要解决这个问题，可以把file_get_contents的超时时间设置的长一些，具体做法如下：

原文地址：PHP stream_cont     原文作者：banu

作用：创建并返回一个文本数据流并应用各种选项，可用于fopen(),file_get_contents()等过程的超时设置、代理服务器、请求方式、头信息设置的特殊过程。

函数原型：resource stream_context_create ([ array $options [, array $params ]] )

用法

例子一：

<?php
$opts = array(   "http-->array(
"method"=&gt;"GET",
"header"=&gt;"Accept-language: en/r/n" .
"Cookie: foo=bar/r/n"
)
);

$context = stream_context_create($opts);

/* Sends an http request to www.heliximitate.cn
with additional headers shown above */
$fp = fopen("http://www.heliximitate.cn", "r", false, $context);
fpassthru($fp);
fclose($fp);
?>
例子二：

<?php
  $opts = array(    "http-->array(
"method"=&gt;"GET",
"header"=&gt;"Accept-language: en/r/n" .
"Cookie: foo=bar/r/n"
)
);

$context = stream_context_create($opts);
?>
You would setup the header this way:

<?php
$opts = array(    "http-->array(
"method"=&gt;"GET",
"header"=&gt;array("Accept-language: en",
"Cookie: foo=bar",
"Custom-Header: value")
)
);

$context = stream_context_create($opts);
?>
例子三：

<?php
$opts = array("http" => array("proxy" => "tcp://127.0.0.1:8080", "request_fulluri" => true));
$context = stream_context_create($opts);

$data = file_get_contents("http://www.heliximitate.cn", false, $context);

echo $data;

?>
例子四：

<?php
function do_post_request($url, $postdata, $files = null)
{
    $data = "";
    $boundary = "---------------------".substr(md5(rand(0,32000)), 0, 10);

    //Collect Postdata
    foreach($postdata as $key => $val)
    {
        $data .= "--$boundary/n";
        $data .= "Content-Disposition: form-data; name=/"".$key."/"/n/n".$val."/n";
    }

    $data .= "--$boundary/n";

    //Collect Filedata
    foreach($files as $key => $file)
    {
        $fileContents = file_get_contents($file["tmp_name"]);

        $data .= "Content-Disposition: form-data; name=/"{$key}/"; filename=/"{$file["name"]}/"/n";
        $data .= "Content-Type: image/jpeg/n";
        $data .= "Content-Transfer-Encoding: binary/n/n";
        $data .= $fileContents."/n";
        $data .= "--$boundary--/n";
    }

    $params = array("http" => array(
           "method" => "POST",
           "header" => "Content-Type: multipart/form-data; boundary=".$boundary,
           "content" => $data
        ));

   $ctx = stream_context_create($params);
   $fp = fopen($url, "rb", false, $ctx);

   if (!$fp) {
      throw new Exception("Problem with $url, $php_errormsg");
   }

   $response = @stream_get_contents($fp);
   if ($response === false) {
      throw new Exception("Problem reading data from $url, $php_errormsg");
   }
   return $response;
}

//set data (in this example from post)

//sample data
$postdata = array(
    "name" => $_POST["name"],
    "age" => $_POST["age"],
    "sex" => $_POST["sex"]
);

//sample image
$files["image"] = $_FILES["image"];

do_post_request("http://www.heliximitate.cn", $postdata, $files);
?>

反思：看到报错，别轻率的定位错误，要认真的看懂错误的根本原因，然后下手。