java - 无法实例化接收器 com.google.firebase.iid.FirebaseInstanceIdReceiver:java.lang.ClassNotFoundException:
问题描述
我检查了很多答案,但它们没有用。我只想创建简单的推送通知应用程序。首先,当我制作一个 apk 并尝试在多个设备上发送通知时,我为单个设备创建了它开始崩溃。
public class MyFirebaseMessagingService extends FirebaseMessagingService {
String TAG ="MALIK";
@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
// ...
sendNotification(remoteMessage.getNotification().getBody());
// TODO(developer): Handle FCM messages here.
Log.d(TAG, "From: " + remoteMessage.getFrom());
// Check if message contains a data payload.
if (remoteMessage.getData().size() > 0) {
Log.d(TAG, "Message data payload: " + remoteMessage.getData());
if (/* Check if data needs to be processed by long-running job */ true) {
// For long-running tasks (10 seconds or more) use Firebase Job Dispatcher.
} else {
// Handle message within 10 seconds
}
}
// Check if message contains a notification payload.
if (remoteMessage.getNotification() != null) {
Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
sendNotification(remoteMessage.getNotification().getBody());
}
// Also if you intend on generating your own notifications as a result of a received FCM
// message, here is where that should be initiated. See sendNotification method below.
}
@Override
public void onNewToken(String token) {
Log.d(TAG, "Refreshed token: " + token);
// If you want to send messages to this application instance or
// manage this apps subscriptions on the server side, send the
// Instance ID token to your app server.
}
private void sendNotification(String messageBody) {
Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
PendingIntent.FLAG_ONE_SHOT);
String channelId = getString(R.string.default_notification_channel_id);
Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
NotificationCompat.Builder notificationBuilder =
new NotificationCompat.Builder(this, channelId)
.setSmallIcon(R.drawable.ic_launcher_background)
.setContentTitle(getString(R.string.fcm_message))
.setContentText(messageBody)
.setAutoCancel(true)
.setSound(defaultSoundUri)
.setContentIntent(pendingIntent);
NotificationManager notificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
// Since android Oreo notification channel is needed.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationChannel channel = new NotificationChannel(channelId,
"Channel human readable title",
NotificationManager.IMPORTANCE_DEFAULT);
notificationManager.createNotificationChannel(channel);
}
notificationManager.notify(0 /* ID of notification */, notificationBuilder.build());
}
}
解决方案
错误可以总结为ClassNotFoundException
。
这意味着代码调用了一个不在类路径中的类。问题可能是因为:
Firebase-iid
需要添加库。// use compile instead of implementation if it's unknown implementation "com.google.firebase:firebase-iid:+" // 18.0.0 or 20.0.0
添加了库
firebase-messaging
(并添加了此类),但它非常旧或非常新,因此与您的代码不兼容。- 确保将 firebase 消息添加到项目中:
// use compile instead of implementation if it's unknown implementation "com.google.firebase:firebase-messaging:+" // 18.0.0 or 20.0.0
- 如果您的代码是旧的(从古老的博文复制),请添加较低的
firebase-messaging
库版本。否则,如果您的代码是新的而您的代码是firebase-messaging
旧的,请尝试升级库版本。
有关firebase 发行说明的更多信息。
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