Magento Soap客户端不能在https上工作

我在Magento soap api connection whenever try to use https as secure url上面临问题。

我的magento系统version CE 1.7 and soap version 1。

系统Url设置

Secure url is  https://www.example.com/
Unsecured  is  http://www.example.com/

当我将安全更改为http://www.example.com/(With out https时

表示soap客户端工作正常。

Also,when secure is https://www.example.com ,it throw below error:
SOAP-ERROR: Parsing WSDL: Couldn't load from 'https://www.example.com/index.php/api/soap/index/?wsdl' : failed to load external entity "https://www.example.com/index.php/api/soap/index/?wsdl

try{
$cli = new SoapClient('http://www.example.com/index.php/api/soap/index/?wsdl');
$session = $cli->login('marketplace_usr', 'ezvendorplus');
$result = $cli->call($session, 'catalog_product.info', 10887);
var_dump($result);
}
catch(Exception $e){
    echo '<pre>';
    var_dump($e);
    }