php - 适用于Android的FCM通知

我尝试使用PHP脚本发送FCM通知，在数据库插入事件中，我尝试从FCM控制台发送，使用topic选项可以正常工作，知道我已使用以下代码将应用程序实例注册到某个主题“ exptopic”在MainActivity.java OnCreate类中：

FirebaseMessaging.getInstance().subscribeToTopic("exptopic");

现在，PHP脚本如下：

function sendMessage($data,$target){
    //FCM api URL
    $url = 'https://fcm.googleapis.com/fcm/send';

    //api_key available in Firebase console -> project settings -> cloud messaging -> server key

    $server_key = "API_KEY";//my api key

    $fields = array();
    $fields['data'] = array('message'=>$data);
    $fields['to'] = $target;

    $headers = array('content-type:application/json',
            'Authorization:key='.$server_key);

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
    $result = curl_exec($ch);

    if($result === FALSE){
        die('FCM Send error: '.curl_error($ch));
        echo 'notification not sent';
    }
    curl_close($ch);
    echo $result;
    return $result;
}

显然$target = "exptopic"，当我运行snedMessage函数时，它将返回以下结果：

{"multicast_id":6779996340041741184,"success":0,"failure":1,"canonical_ids":0,"results":[{"error":"InvalidRegistration"}]}

有人可以帮忙吗？

最佳答案

基于this documentation，to字段应为/topics/exptopic