接收新的FCM消息（前台和后台）时Android应用程序崩溃

贵有恒，何必三更起、五更眠、最无益，只怕一日曝、十日寒。这篇文章主要讲述接收新的FCM消息（前台和后台）时Android应用程序崩溃相关的知识，希望能为你提供帮助。
我正在努力在我的应用中实施FCM。我正在按照文档中的指南进行操作，并尝试按照文档中的建议实现一个简单的测试，但每当我从控制台发送通知时，应用程序崩溃，天气就在前台或后台。
**更新：我已经删除了服务类，它在gradle中的减速和实现。如果我尝试测试消息，应用程序仍会崩溃。它不应该完全不受它的影响吗？
这是我的扩展课程：

import android.util.Log import com.google.firebase.auth.FirebaseAuth import com.google.firebase.database.FirebaseDatabase import com.google.firebase.iid.FirebaseInstanceId import com.google.firebase.messaging.FirebaseMessagingService import com.google.firebase.messaging.RemoteMessageclass MyFirebaseMessagingService : FirebaseMessagingService() {override fun onMessageReceived(p0: RemoteMessage?) { super.onMessageReceived(p0)Log.d("newMessage", p0!!.notification!!.body) }override fun onNewToken(p0: String?) { super.onNewToken(p0) FirebaseInstanceId.getInstance().instanceId.addOnSuccessListener { idResult -> val uid = FirebaseAuth.getInstance().uid ?: ""val token = idResult.tokenval userRef = FirebaseDatabase.getInstance().getReference("/users/$uid/services/firebase-token") userRef.setValue(token) } } }

这是我的表现：

< service android:name=".otherClasses.MyFirebaseMessagingService" android:exported="false"> < intent-filter> < action android:name="com.google.firebase.MESSAGING_EVENT" /> < /intent-filter> < /service>

这是崩溃日志：

2019-04-18 11:45:44.007 21257-21295/co.getdere E/AndroidRuntime: FATAL EXCEPTION: Firebase-WrappedFirebaseMessagingService Process: co.getdere, PID: 21257 java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference at android.content.ContextWrapper.getPackageName(ContextWrapper.java:135) at com.google.firebase.messaging.zzb.< init> (Unknown Source:5) at com.google.firebase.messaging.FirebaseMessagingService.zzd(Unknown Source:58) at com.google.firebase.iid.zzb.run(Unknown Source:2) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) at com.google.android.gms.common.util.concurrent.zza.run(Unknown Source:6) at java.lang.Thread.run(Thread.java:764)

答案试试吧。它可能会奏效

class MyFirebaseMessagingService : FirebaseMessagingService() { companion object {private val TAG = "MyFirebaseMsgService" }override fun onNewToken(s: String?) { super.onNewToken(s) //Displaying token on logcat Log.e(TAG, "Refreshed token: " + s!!) }override fun onMessageReceived(remoteMessage: RemoteMessage?) { Log.e(TAG, "onMessageReceived") } }

【接收新的FCM消息（前台和后台）时Android应用程序崩溃】将其添加到清单文件中

< service android:name=".fcm.MyFirebaseMessagingService" android:exported="false"> < intent-filter> < action android:name="com.google.firebase.MESSAGING_EVENT" /> < /intent-filter> < /service>