Flutter firebase_messaging android应用程序在.getToken()调用上崩溃

Question

我正在尝试将firebase_messaging包与我的flutter应用程序集成。通常，它(版本7.0.3(与我正在使用的代码(见下文(配合得很好，但由于发布了空安全版本，我的代码不再工作了。我想知道是否有人能帮我找出我做错了什么？

导致错误的代码

try {
fcmToken = await _firebaseMessaging.getToken();
} catch (error) {
print(error);
}

错误输出

E/AndroidRuntime( 8942): java.lang.NoClassDefFoundError: Failed resolution of: Lcom/google/firebase/iid/Metadata;
E/AndroidRuntime( 8942):    at io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin.lambda$getToken$1$FlutterFirebaseMessagingPlugin(FlutterFirebaseMessagingPlugin.java:165)
E/AndroidRuntime( 8942):    at io.flutter.plugins.firebase.messaging.-$$Lambda$FlutterFirebaseMessagingPlugin$p8YQXDuFBNIxl8PFaPCQJtYc3sw.call(Unknown Source:4)
E/AndroidRuntime( 8942):    at com.google.android.gms.tasks.zzv.run(Unknown Source:2)
E/AndroidRuntime( 8942):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
E/AndroidRuntime( 8942):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
E/AndroidRuntime( 8942):    at java.lang.Thread.run(Thread.java:923)
E/AndroidRuntime( 8942): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.firebase.iid.Metadata" on path: DexPathList[[zip file "/data/app/~~uCa7QFzhvu5i_TZpnqat0w==/com.example.****-1cbY-LKuCoOsfZybV-Gq6g==/base.apk"],nativeLibraryDirectories=[/data/app/~~uCa7QFzhvu5i_TZpnqat0w==/com.example.****-1cbY-LKuCoOsfZybV-Gq6g==/lib/x86, /data/app/~~uCa7QFzhvu5i_TZpnqat0w==/com.example.****-1cbY-LKuCoOsfZybV-Gq6g==/base.apk!/lib/x86, /system/lib, /system_ext/lib]]
E/AndroidRuntime( 8942):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:207)
E/AndroidRuntime( 8942):    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
E/AndroidRuntime( 8942):    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
E/AndroidRuntime( 8942):    ... 6 more

应用程序->src->main->kotlin->应用程序.kt

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin
class Application() : FlutterApplication(), PluginRegistry.PluginRegistrantCallback {
override fun registerWith(registry: PluginRegistry?) {
val key: String? = FlutterFirebaseMessagingPlugin::class.java.canonicalName
if (!registry?.hasPlugin(key)!!) {
FlutterFirebaseMessagingPlugin.registerWith(registry?.registrarFor("io.flutter.plugins.firebase.messaging.FlutterFirebaseMessagingPlugin"));
}
}
}

应用程序->src->main->kotlin->主要活动.kt

import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant
class MainActivity: FlutterActivity() {
override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
GeneratedPluginRegistrant.registerWith(flutterEngine);
}
}

Answer 1

对我来说，它通过从降级来工作

com.google.firebase:firebase-bom:28.0.1

至

com.google.firebase:firebase-bom:27.0.0

提示：这是这些版本的临时解决方案：

firebase_messaging: ^9.1.4firebase_core: ^1.1.1

Answer 2

解决方案

出于某种原因，我将onBackgroundMessageHandler作为类方法放在了我的项目中。通过简单地将该方法作为顶级函数来解决问题。

之前

class MyNotificationClass {
Future<dynamic> onBackgroundMessageHandler(RemoteMessage message) async {
print('on Background $message');
}
// ...
}

之后

Future<dynamic> onBackgroundMessageHandler(RemoteMessage message) async {
print('on Background $message');
}
class MyNotificationClass {
// ...
}

安卓系统->应用程序->src->build.gradle

dependencies {
implementation 'com.google.android.material:material:1.3.0'
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
// Import the Firebase BoM
implementation platform('com.google.firebase:firebase-bom:26.3.0')
// Add the dependency for the Firebase SDK for Google Analytics
// When using the BoM, don't specify versions in Firebase dependencies
implementation 'com.google.firebase:firebase-analytics'
implementation 'com.google.firebase:firebase-auth'
implementation 'com.google.firebase:firebase-messaging'
}
// ADD THIS AT THE BOTTOM
apply plugin: 'com.google.gms.google-services'

安卓系统->build.gradle

buildscript {
ext.kotlin_version = '1.3.50'
repositories {
google()
jcenter()
}
dependencies {
//classpath 'com.android.tools.build:gradle:4.1.0'
classpath 'com.android.tools.build:gradle:3.5.3' // 3.5.0
classpath 'com.google.gms:google-services:4.3.2' // 4.3.2
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
allprojects {
repositories {
google()
jcenter()
}
}
rootProject.buildDir = '../build'
subprojects {
project.buildDir = "${rootProject.buildDir}/${project.name}"
project.evaluationDependsOn(':app')
}
task clean(type: Delete) {
delete rootProject.buildDir
}

pubspec.yaml

cloud_firestore: ^1.0.5 #^0.14.4 #^0.13.5                     
firebase_database: ^6.1.2 #4.4.0                             
firebase_core: ^1.0.3 #^0.5.3 #^0.4.4+3                       
firebase_auth: ^1.1.0 #0.18.4+1 #^0.16.0                     
firebase_messaging: ^9.1.1 #7.0.3 #^6.0.15                   
firebase_dynamic_links: ^2.0.0 #0.6.3 #^0.5.0+11             
firebase_analytics: ^8.0.0 #6.3.0 #^5.0.11                   
cloud_functions: ^1.0.3 #0.7.2 #^0.5.0                       

AndroidManifest.xml

<application
android:name=".Application"
android:label="app name"
android:usesCleartextTraffic="true"
android:icon="@mipmap/ic_launcher">
<activity
android:name=".MainActivity"
android:launchMode="singleTop"
android:theme="@style/LaunchTheme"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
android:hardwareAccelerated="true"
android:windowSoftInputMode="adjustResize">
<!-- Specifies an Android theme to apply to this Activity as soon as
the Android process has started. This theme is visible to the user
while the Flutter UI initializes. After that, this theme continues
to determine the Window background behind the Flutter UI. -->
<meta-data
android:name="io.flutter.embedding.android.NormalTheme"
android:resource="@style/NormalTheme"
/>
<!-- Displays an Android View that continues showing the launch screen
Drawable until Flutter paints its first frame, then this splash
screen fades out. A splash screen is useful to avoid any visual
gap between the end of Android's launch screen and the painting of
Flutter's first frame. -->
<meta-data
android:name="io.flutter.embedding.android.SplashScreenDrawable"
android:resource="@drawable/launch_background"
/>
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
<intent-filter>
<action android:name="FLUTTER_NOTIFICATION_CLICK" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.firebase.messaging.default_notification_icon"
android:resource="@mipmap/ic_notification" />
<!-- Don't delete the meta-data below.
This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
<meta-data
android:name="flutterEmbedding"
android:value="2" />
</application>