PHP stream_context_create()作用和用法分析

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

1. 例子一

   <?php
       $opts = [
           'http' => [
               'method'=>"GET",
               'header'=>"Accept-language: en
   " .
               "Cookie: foo=bar
   "
           ]
       ];
       $context = stream_context_create($opts);
       $fp = fopen('//www.jjxhp.com', 'r', false, $context);
       fpassthru($fp);
       fclose($fp);
   ?>
   

2. 案例二

   <?php
   	$opts = [ 
   		'http' => [
   			'method'=>"GET",
   			'header'=>"Accept-language: en
   " .
   			"Cookie: foo=bar
   "
   		]
   	];
   	$context = stream_context_create($opts);
   
   	//You would setup the header this way:
   
       $opts = [ 
   	    'http' => [
   			'method'=>"GET",
   			'header'=> [
   				"Accept-language: en",
   				"Cookie: foo=bar",
   				"Custom-Header: value"
   			]
   	 	]
       ];
       $context = stream_context_create($opts);
   ?>
   

3. 案例三

   <?php
   	$opts = [
   		'http' => [
   			'proxy' => 'tcp://127.0.0.1:8080', 
   			'request_fulluri' => true
   		]
   	];
   	$context = stream_context_create($opts);
   	$data = file_get_contents('//www.www.jjxhp', false, $context);
   	echo $data;
   ?>
   

4. 案例四

   <?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
   ";
   			$data .= "Content-Disposition: form-data; name="".$key.""
   
   ".$val."
   ";
   		}
   		$data .= "--$boundary
   ";
   		//Collect Filedata
   		foreach($files as $key => $file)
   		{
   			$fileContents = file_get_contents($file['tmp_name']);
   			$data .= "Content-Disposition: form-data; name="{$key}"; filename="{$file['name']}"
   ";
   			$data .= "Content-Type: image/jpeg
   ";
   			$data .= "Content-Transfer-Encoding: binary
   
   ";
   			$data .= $fileContents."
   ";
   			$data .= "--$boundary--
   ";
   		}
   		$params = [
   			'http' => [
   				'method' => 'POST',
   				'header' => 'Content-Type: multipart/form-data; boundary='.$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 = [
   		'name' => $_POST['name'],
   		'age'  => $_POST['age'],
   		'sex'  => $_POST['sex']
   	];
   	//sample image
   	$files['image'] = $_FILES['image'];
   	do_post_request("//www.jjxhp.com", $postdata, $files);
   ?>