Flutter app not finding application in manifest - flutter

Question

I have tried adding Firebase Messaging to my Flutter app, and according to this tutorial I should add a custom application name to the manifest file.
Problem
App won't launch because Flutter can't find my custom application file
Cause
I have tried integrating FlutterFire / Firebase Cloud Messaging with flutter
Request
All I care about is receiving push notifications (foreground + background) on the Flutter app, if this is not the correct method to go about it, please let tell me how I can enable this for Android devices
Logs & Outputs
My manifest is
package="com.blabla.blabla">
<!-- Default is android:name="io.flutter.app.FlutterApplication" -->
<!-- FOR PUSH NOIFICATION IN BACKGROUND android:name=".Application" -->
<application
android:name=".Application"
android:label="BlaBla"
android:icon="#mipmap/launcher_icon">
<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">
<!-- this is the push notification intent -->
<intent-filter>
<action android:name="FLUTTER_NOTIFICATION_CLICK" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
<meta-data
android:name="io.flutter.embedding.android.NormalTheme"
android:resource="#style/NormalTheme"
/>
The application file is located in the same folder as Manifest (app->src->main)
import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService
class Application : FlutterApplication(), PluginRegistrantCallback {
override fun onCreate() {
super.onCreate()
FlutterFirebaseMessagingService.setPluginRegistrant(this)
}
override fun registerWith(registry: PluginRegistry?) {
io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin.registerWith(
registry?.registrarFor(
"io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
}
}
And my specific (app->build.gradle) is as follows
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
localPropertiesFile.withReader('UTF-8') { reader ->
localProperties.load(reader)
}
}
def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}
def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
flutterVersionCode = '1'
}
def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
flutterVersionName = '1.0'
}
apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services' // Google Services plugin
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
android {
compileSdkVersion 30
sourceSets {
main.java.srcDirs += 'src/main/kotlin'
}
lintOptions {
disable 'InvalidPackage'
}
defaultConfig {
applicationId "com.bla.bla"
minSdkVersion 21
targetSdkVersion 30
// multiDexEnabled true
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig signingConfigs.debug
}
}
splits {
// Configures multiple APKs based on ABI.
abi {
// Enables building multiple APKs per ABI.
enable true
// By default all ABIs are included, so use reset() and include to specify that we only
// want APKs for x86 and x86_64.
// Resets the list of ABIs that Gradle should create APKs for to none.
reset()
// Specifies a list of ABIs that Gradle should create APKs for.
include "x86", "x86_64", "armeabi", "armeabi-v7a", "arm64-v8a"
// Specifies that we do not want to also generate a universal APK that includes all ABIs.
universalApk true
}
}
}
flutter {
source '../..'
}
dependencies {
// implementation "androidx.multidex:multidex:2.0.1"
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
// Import the BoM for the Firebase platform
implementation platform('com.google.firebase:firebase-bom:26.6.0')
// Declare the dependencies for the Firebase Cloud Messaging and Analytics libraries
// When using the BoM, you don't specify versions in Firebase library dependencies
implementation 'com.google.firebase:firebase-messaging-ktx:21.0.1'
// implementation 'com.google.firebase:firebase-analytics-ktx'
}
This is the general build.gradle
ext.kotlin_version = '1.3.50'
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.5.4'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
classpath 'com.google.gms:google-services:4.3.5' // Google Services plugin
}
}
allprojects {
repositories {
google()
jcenter()
}
}
rootProject.buildDir = '../build'
subprojects {
project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
project.evaluationDependsOn(':app')
}
task clean(type: Delete) {
delete rootProject.buildDir
}
This is the console output of every launch
E/AndroidRuntime(31070): java.lang.RuntimeException: Unable to instantiate application com.bla.bla.Application: java.lang.ClassNotFoundException: Didn't find class "com.bla.bla.Application" on path: DexPathList[[zip file "/data/app/com.bla.bla-bPPOfcyKzIbhjyMWE3Q9NQ==/base.apk"],nativeLibraryDirectories=[/data/app/com.bla.bla-bPPOfcyKzIbhjyMWE3Q9NQ==/lib/arm64, /data/app/com.bla.bla-bPPOfcyKzIbhjyMWE3Q9NQ==/base.apk!/lib/arm64-v8a, /system/lib64, /system/product/lib64]]
E/AndroidRuntime(31070): at android.app.LoadedApk.makeApplication(LoadedApk.java:1231)
E/AndroidRuntime(31070): at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6431)
E/AndroidRuntime(31070): at android.app.ActivityThread.access$1300(ActivityThread.java:219)
E/AndroidRuntime(31070): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1859)
E/AndroidRuntime(31070): at android.os.Handler.dispatchMessage(Handler.java:107)
E/AndroidRuntime(31070): at android.os.Looper.loop(Looper.java:214)
E/AndroidRuntime(31070): at android.app.ActivityThread.main(ActivityThread.java:7356)
E/AndroidRuntime(31070): at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(31070): at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:491)
E/AndroidRuntime(31070): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
I DON'T KNOW WHAT ELSE TO DO!! I have spent countless hours trying to solve it, would appreciate it if anybody knows how to fix this issue!!
Currently running on a Google Pixel 2 Android 10 device.

Answer 1

My bad,
I had accidentally put the Application.kt file in the android > app folder instead of android > app > src > your-package-name.
Once I moved the custom Application.kt next to the MainActivity.kt, all seems to work well!

Answer 2

Try modifying your AndroidManifest.xml file to look like below. This is working.
This is only for the <activity </activity> tags. And set your minSdkVersion to 21 in android/app/build.gradle to overcome possible multidex errors.
<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>