file_get_contents获取不到网页内容的解决方法

代码如下:

PHP
$url = "http://jb51.cc/index.html";
$ch = curl_init();
$timeout = 5;
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT,$timeout);
//在需要用户检测的网页里需要增加下面两行
//curl_setopt($ch,CURLOPT_HTTPAUTH,CURLAUTH_ANY);
//curl_setopt($ch,CURLOPT_USERPWD,US_NAME.":".US_PWD);
$contents = curl_exec($ch);
curl_close($ch);
echo $contents;
?>