Firebase remoteMessage getData 正確的 NullPointer 處理

Question

我在处理来自remoteMessage的NullPointer 异常时遇到了一些问题。

我尝试进行简单的检查：

Map<String, String> data = remoteMessage.getData();
if(data != null) {
        Log.d(TAG, remoteMessage.getData().get("lat"));
        Log.d(TAG, remoteMessage.getData().get("lng"));
    }

我也更加努力：

  if(remoteMessage.getData().get("lat") != null) {
        Log.d(TAG, remoteMessage.getData().get("lat"));
    }

但它总是与 NullPointer 一起崩溃：

05-29 10:22:33.112 21028-24256/com.coderspeak.smog_app E/AndroidRuntime: FATAL EXCEPTION: pool-12-thread-1
                                                                     Process: com.coderspeak.smog_app, PID: 21028
                                                                     java.lang.NullPointerException: println needs a message
                                                                         at android.util.Log.println_native(Native Method)
                                                                         at android.util.Log.d(Log.java:139)
                                                                         at com.coderspeak.smog_app.services.fcm.AppFirebaseMessagingService.onMessageReceived(AppFirebaseMessagingService.java:50)
                                                                         at com.google.firebase.messaging.FirebaseMessagingService.zzl(Unknown Source)
                                                                         at com.google.firebase.messaging.FirebaseMessagingService.zzJ(Unknown Source)
                                                                         at com.google.firebase.messaging.FirebaseMessagingService.handleIntent(Unknown Source)
                                                                         at com.google.firebase.iid.zzb$1.run(Unknown Source)
                                                                         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
                                                                         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)

我怎样才能对此进行适当的检查？

Answer 1

你试过这种方式吗？

if (remoteMessage != null &&
    remoteMessage.getData() != null) {
    String yourMessage = remoteMessage.getData().get("lat"));
    if (yourMessage != null) {
         Log.d(TAG, yourMessage);
    }
}