摘要: 当http请求出现400错误时，一般是http请求无效(bad request)，url参数编码格式不正确导致。而url是有一定格式要求的，一般只能使用英文字母、阿拉伯数字和一些特殊字符，其他字符如空格和双引号需要经过编码后才能用户url。 1.在浏览器中直接访问时浏览器会自动进行编码处理 2.但是在程序中直接调用时则需要事先对url进行编码，如php使用curl_exec调用时需要对空格等非法字符进行编码。 3.特别是针对url参数中包含json数据值需要多加注意。
背景
现象一-php封装的http请求接口调用url
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1.response的rawheader值显示400错误
HTTP/1.1 400 Unknown VersionServer: Tengine/2.0.3Date: Tue, 19 Jul 2016 07:38:15 GMTContent-Length: 0Connection: keep-alive
2.自己封装的发送http请求接口
/**
* 发送httpful get请求
* @param [array] $params [description]
* @return [object] [description]
*/public function sendGetRequest($serverUrl,$params){ try{
$str_params = ''; foreach ($params as $key => $value) {
$str_params .= "&$key=".$value;
}
$response = \Httpful\Request::get($serverUrl.$str_params)->send(); return $response->body;
}catch(Execption $e){ return array("statuscode"=>'-1',"message"=>'服务器出错了');
}
}3.Request.php封装的Request对象的send方法
nategood/httpful中的Request::send方法使用php的curl_exec接口发起http请求。
/**
* Actually send off the request, and parse the response
* @return string|associative array of parsed results
* @throws ConnectionErrorException when unable to parse or communicate w server
*/public function send(){ if (!$this->hasBeenInitialized()) $this->_curlPrep();
$result = curl_exec($this->_ch); if ($result === false) { if ($curlErrorNumber = curl_errno($this->_ch)) {
$curlErrorString = curl_error($this->_ch); $this->_error($curlErrorString); throw new ConnectionErrorException('Unable to connect: ' . $curlErrorNumber . ' ' . $curlErrorString);
} $this->_error('Unable to connect.'); throw new ConnectionErrorException('Unable to connect.');
}
$info = curl_getinfo($this->_ch); // Remove the "HTTP/1.x 200 Connection established" string and any other headers added by proxy
$proxy_regex = "/HTTP\/1\.[01] 200 Connection established.*?\r\n\r\n/s"; if ($this->hasProxy() && preg_match($proxy_regex, $result)) {
$result = preg_replace($proxy_regex, '', $result);
}
$response = explode("\r\n\r\n", $result, 2 + $info['redirect_count']);
$body = array_pop($response);
$headers = array_pop($response);
curl_close($this->_ch); return new Response($body, $headers, $this, $info);
}4.curl_exec调用前url值
http://192.168.59.146/api?version=1.0&format=json&appkey=KtSNKxk3&access_token=changyanyun&method=pan.file.export&uid=3062000039000412278&fileId=3aaaa5c8-3eaa-4511-91e7-46831d418f10&fileIndex={"lifecycle":{"auditstatus":"0"},"general":{"source":"UGC","creator":"\u6559\u5e080523","uploader":"gsres_iflytek_f968bca78360d38abcbaf23a5a318b12","extension":"ppt","title":"Unit12 What did you do last weekdend\u8bfe\u65f64\uff081\uff09"},"properties":{"subject":["01"],"edition":["01"],"stage":["010001"],"book":["01010101-001"],"unit":["01"],"course":[""],"unit1":["01"],"unit2":[""],"unit3":[""],"phase":["03"],"type":["0100"],"rrtlevel1":["08"]}}现象二-浏览器中直接访问url
http://192.168.59.146/api?version=1.0&format=json&appkey=KtSNKxk3&access_token=changyanyun&method=pan.file.export&uid=3062000039000412278&fileId=3aaaa5c8-3eaa-4511-91e7-46831d418f10&fileIndex={ %22lifecycle%22:{ %22auditstatus%22:%220%22},%22general%22:{ %22source%22:%22UGC%22,%22creator%22:%22\u6559\u5e080523%22,%22uploader%22:%22gsres_iflytek_f968bca78360d38abcbaf23a5a318b12%22,%22extension%22:%22ppt%22,%22title%22:%22Unit12%20What%20did%20you%20do%20last%20weekdend\u8bfe\u65f64\uff081\uff09%22},%22properties%22:{ %22subject%22:[%2201%22],%22edition%22:[%2201%22],%22stage%22:[%22010001%22],%22book%22:[%2201010101-001%22],%22unit%22:[%2202%22],%22course%22:[%22%22],%22unit1%22:[%2202%22],%22unit2%22:[%22%22],%22unit3%22:[%22%22],%22phase%22:[%2203%22],%22type%22:[%220100%22],%22rrtlevel1%22:[%2208%22]}}原因分析
对比现象一和现象二中的url值，可以发现：
fileIndex参数值为json字符串
fileIndex参数值中的title属性值中的空格字符在现象二中被编码为%20,且双引号"被编码为%22，此操作为浏览器自动执行
将url中的空格进行编码后，curl_exec接口返回200
测试代码
_ch)) {
$curlErrorString = curl_error($this->_ch); $this->_error($curlErrorString); throw new ConnectionErrorException('Unable to connect: ' . $curlErrorNumber . ' ' . $curlErrorString);
} $this->_error('Unable to connect.'); throw new ConnectionErrorException('Unable to connect.');
}
var_dump("ch");
var_dump($ch);
$info = curl_getinfo($ch);
var_dump("info");
var_dump($info);// Remove the "HTTP/1.x 200 Connection established" string and any other headers added by proxy$proxy_regex = "/HTTP\/1\.[01] 200 Connection established.*?\r\n\r\n/s";if (preg_match($proxy_regex, $result)) {
$result = preg_replace($proxy_regex, '', $result);
}
$response = explode("\r\n\r\n", $result, 2 + $info['redirect_count']);
var_dump("response");
var_dump($response);
$body = array_pop($response);
var_dump("body");
var_dump($body);
$headers = array_pop($response);
var_dump("headers");
var_dump($headers);// 关闭cURL资源，并且释放系统资源curl_close($ch);?>百分号编码(即url编码)
一般来说，URL只能使用英文字母、阿拉伯数字和某些标点符号，不能使用其他文字和符号。阮一峰在他的博文中提到，网络标准RFC 1738做了硬性规定:
"...Only alphanumerics [0-9a-zA-Z], the special characters "$-.+!*'()," [not including the quotes - ed], and reserved characters used for their reserved purposes may be used unencoded within a URL."
"只有字母和数字[0-9a-zA-Z]、一些特殊符号"$-.+!*'(),"[不包括双引号]、以及某些保留字，才可以不经过编码直接用于URL。"
url编码是特定上下文的统一资源定位符 (URL)的编码机制,服务器解析http请求时如果遇到非标准字符，会对该非标准字符进行编码
总结
当http请求出现400错误时，一般是http请求无效(bad request)，url参数编码格式不正确导致。而url是有一定格式要求的，一般只能使用英文字母、阿拉伯数字和一些特殊字符，其他字符如空格和双引号需要经过编码后才能用户url。
在浏览器中直接访问时浏览器会自动进行编码处理
但是在程序中直接调用时则需要事先对url进行编码，如php使用curl_exec调用时需要对空格等非法字符进行编码。
特别是针对url参数中包含json数据值需要多加注意。
