[Flutter]Android12でアプリがクラッシュしてデバッグできない

解決策

https://stackoverflow.com/questions/61046199/java-lang-runtimeexception-unable-to-instantiate-activity-in-flutter
こちらのサイトを参考にビルドまでは出来るようになりました。
Android12の端末で起動できるかはまだ不明なので、確認が取れ次第解決済みにします。

現状

iOSとAndroidアプリをリリースしたのですが,
Android12の端末がアプリがインストール出来るが、起動できず、クラッシュし、
アプリが継続して停止していますと表示されます。

環境

[✓] Flutter (Channel stable, 2.10.4, on macOS 12.2.1 21D62 darwin-x64, locale ja-JP)
[✓] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
[✓] Xcode - develop for iOS and macOS (Xcode 13.3.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2021.1)
[✓] VS Code (version 1.66.2)
[✓] Connected device (2 available)
[✓] HTTP Host Availability

デバッグ端末
Pixel4 - API level 32 - Android12

問題

元々Emulatorでは開けたのですが、compileSdkVersionを31に変更し、
SDK ManagerでAndroid SDK Buildをアップデート、Android12をインストールしました。その後、デバッグしてみるとコンソールに以下のエラーが出ました。

Dart
1E/AndroidRuntime(19282): FATAL EXCEPTION: main
2E/AndroidRuntime(19282): Process: com.app.attendanc_management_app, PID: 19282
3E/AndroidRuntime(19282): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.app.attendanc_management_app/com.app.attendanc_management_app.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.app.attendanc_management_app.MainActivity" on path: DexPathList[[zip file "/data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/base.apk"],nativeLibraryDirectories=[/data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/lib/x86_64, /data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/base.apk!/lib/x86_64, /system/lib64, /system_ext/lib64]]
4E/AndroidRuntime(19282): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3591)
5E/AndroidRuntime(19282): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3842)
6E/AndroidRuntime(19282): 	at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:103)
7E/AndroidRuntime(19282): 	at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
8E/AndroidRuntime(19282): 	at android.app.ActivityThread.main(ActivityThread.java:7842)
9E/AndroidRuntime(19282): 	at java.lang.reflect.Method.invoke(Native Method)
10E/AndroidRuntime(19282): 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
11E/AndroidRuntime(19282): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
12E/AndroidRuntime(19282): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.app.attendanc_management_app.MainActivity" on path: DexPathList[[zip file "/data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/base.apk"],nativeLibraryDirectories=[/data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/lib/x86_64, /data/app/~~IzjC1wYkYt43ic3kTwEE0Q==/com.app.attendanc_management_app-dWEZ4IHdQ8bWoaBXQz5xEw==/base.apk!/lib/x86_64, /system/lib64, /system_ext/lib64]]
13E/AndroidRuntime(19282): 	at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:218)
14E/AndroidRuntime(19282): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
15E/AndroidRuntime(19282): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
16E/AndroidRuntime(19282): 	at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
17E/AndroidRuntime(19282): 	at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:45)
18E/AndroidRuntime(19282): 	at android.app.Instrumentation.newActivity(Instrumentation.java:1285)
19E/AndroidRuntime(19282): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3578)
20E/AndroidRuntime(19282): 	... 12 more

見解

自分も初めてのエラーだったので調べてみたら

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo

このエラーはたくさん記事が出てきて確認してみたのですが、記述を追加する場合などは自分はどれも記述してあり、今まではデバッグできてEmulatorも動いていたので何が原因なのか掴めていません。flutter cleanとflutter pub getをしてみましたが変わらずでした。

設定周り

android/build.gradle

Dart
1buildscript {
2    ext.kotlin_version = '1.6.21'
3    repositories {
4        google()
5        mavenCentral()
6    }
7
8    dependencies {
9        classpath 'com.android.tools.build:gradle:4.2.0'
10        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
11        classpath 'com.google.gms:google-services:4.3.10'
12    }
13}
14
15allprojects {
16    repositories {
17        google()
18        mavenCentral()
19    }
20}

android/app/build.gradle

Dart
1android {
2    compileSdkVersion 31
3//    デバッグシンボル用
4    ndkVersion "24.0.8215888"
5
6    compileOptions {
7        sourceCompatibility JavaVersion.VERSION_1_8
8        targetCompatibility JavaVersion.VERSION_1_8
9    }
10
11    kotlinOptions {
12        jvmTarget = '1.8'
13    }
14
15    sourceSets {
16        main.java.srcDirs += 'src/main/kotlin'
17    }
18
19    defaultConfig {
20        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
21        applicationId "com.app.attendanc_management_app"
22        minSdkVersion 25
23        targetSdkVersion 31
24        versionCode flutterVersionCode.toInteger()
25        versionName flutterVersionName
26        multiDexEnabled true 
27    }
28
29    signingConfigs {
30        release {
31            keyAlias keystoreProperties['keyAlias']
32            keyPassword keystoreProperties['keyPassword']
33            storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
34            storePassword keystoreProperties['storePassword']
35        }
36    }
37
38    buildTypes {
39        release {
40            // TODO: Add your own signing config for the release build.
41            // Signing with the debug keys for now, so `flutter run --release` works.
42            signingConfig signingConfigs.release
43            ndk {
44                debugSymbolLevel 'SYMBOL_TABLE'
45            }
46        }
47    }
48}
49
50flutter {
51    source '../..'
52}
53
54dependencies {
55    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
56}
57
58apply plugin: 'com.google.gms.google-services'

android/app/src/main/AndroidManifest.xml

Dart
1<manifest xmlns:android="http://schemas.android.com/apk/res/android"
2    package="com.app.attendanc_management_app">
3    <!-- <uses-permission android:name="android.permission.SEND_SMS"/> -->
4   <application
5        android:label="シュッ席"
6        android:name="${applicationName}"
7        android:icon="@mipmap/ic_launcher">
8        <activity
9            android:name=".MainActivity"
10            android:exported="true"
11            android:launchMode="singleTop"
12            android:theme="@style/LaunchTheme"
13            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
14            android:hardwareAccelerated="true"
15            android:windowSoftInputMode="adjustResize">
16            <!-- Specifies an Android theme to apply to this Activity as soon as
17                 the Android process has started. This theme is visible to the user
18                 while the Flutter UI initializes. After that, this theme continues
19                 to determine the Window background behind the Flutter UI. -->
20            <meta-data
21              android:name="io.flutter.embedding.android.NormalTheme"
22              android:resource="@style/NormalTheme"
23              />
24            <intent-filter>
25                <action android:name="android.intent.action.MAIN"/>
26                <category android:name="android.intent.category.LAUNCHER"/>
27            </intent-filter>
28        </activity>
29        <!-- Don't delete the meta-data below.
30             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
31        <meta-data
32            android:name="flutterEmbedding"
33            android:value="2" />
34    </application>
35</manifest>