使用PHP检查流是否打开或关闭TWITCH API

The following ifalways return "Stream is Online!", even when "Stream is Offline!"

Could anyone point me the error?

    <?php
    $opts    = array(
        'http' => array(
            'method' => "GET",
            'header' => "Client-id: clientidhere
" . "Accept: application/vnd.twitchtv.v5+json
"
        )
    );
    $context = stream_context_create($opts);
    $file    = file_get_

contents('https://api.twitch.tv/kraken/streams/somestreaming', false, $context);
$json    = json_decode($file);


if (($json->stream === "NULL") || ($json->stream === "null")) {
    echo "Stream is Offline!";
} else {
    echo "Stream is Online!";
}

?>

For me, I write as follows.

    if (empty($http_response_header)){
        echo "Stream is Offline!
";
    } else {
        echo "Stream is Online!
";
    }

Note: $http_response_header is not empty when first request was succeeded then second request was failed, so you should need to empty $http_response_header before each requests.

$http_response_header = '';
file_get_contents(...);