淘宝API grant type is empty错误|淘宝Oauth grant type is empty错误

事实上，大部分人不会忘了设置grant_type，这个报错最可能的原因还是php curl设置问题。

事实上淘宝SDK有封装curl操作，不需要自己去写这些代码。

封装的函数在TopClient中的curl()方法。

附代码如下：

public function curl($url, $postFields = null)
{
	$ch = curl_init();
	curl_setopt($ch, CURLOPT_URL, $url);
	curl_setopt($ch, CURLOPT_FAILONERROR, false);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
	if ($this->readTimeout) {
		curl_setopt($ch, CURLOPT_TIMEOUT, $this->readTimeout);
	}
	if ($this->connectTimeout) {
		curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $this->connectTimeout);
	}
	//https 请求
	if(strlen($url) > 5 && strtolower(substr($url,0,5)) == "https" ) {
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
		curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
	}

	if (is_array($postFields) && 0 < count($postFields))
	{
		$postBodyString = "";
		$postMultipart = false;
		foreach ($postFields as $k => $v)
		{
			if("@" != substr($v, 0, 1))//判断是不是文件上传
			{
				$postBodyString .= "$k=" . urlencode($v) . "&"; 
			}
			else//文件上传用multipart/form-data，否则用www-form-urlencoded
			{
				$postMultipart = true;
			}
		}
		unset($k, $v);
		curl_setopt($ch, CURLOPT_POST, true);
		if ($postMultipart)
		{
			curl_setopt($ch, CURLOPT_POSTFIELDS, $postFields);
		}
		else
		{
			curl_setopt($ch, CURLOPT_POSTFIELDS, substr($postBodyString,0,-1));
		}
	}
	$reponse = curl_exec($ch);
	
	if (curl_errno($ch))
	{
		throw new Exception(curl_error($ch),0);
	}
	else
	{
		$httpStatusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
		if (200 !== $httpStatusCode)
		{
			throw new Exception($reponse,$httpStatusCode);
		}
	}
	curl_close($ch);
	return $reponse;
}