无法使用 Hilt 注入 workmanager 构造函数

Question

I'm developing an Android app. and I'm trying to use hilt with workmanager constructor but it does not work and gives me this error:

2020-08-18 19:01:09.989 18125-18759/com. E/WM-WorkerFactory: Could not instantiate example.android.app.database.DeleteNotesWorker
    java.lang.NoSuchMethodException: example.android.app.database.DeleteNotesWorker.<init> [class android.content.Context, class androidx.work.WorkerParameters]
        at java.lang.Class.getConstructor0(Class.java:2328)
        at java.lang.Class.getDeclaredConstructor(Class.java:2167)
        at androidx.work.WorkerFactory.createWorkerWithDefaultFallback(WorkerFactory.java:95)
        at androidx.work.impl.WorkerWrapper.runWorker(WorkerWrapper.java:242)
        at androidx.work.impl.WorkerWrapper.run(WorkerWrapper.java:136)
        at androidx.work.impl.utils.SerialExecutor$Task.run(SerialExecutor.java:91)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:764)

this is the worker class:

class DeleteNotesWorker @WorkerInject constructor(
    @Assisted context: Context,
    @Assisted workerParams: WorkerParameters,
    private val dao : NotesDao
) : CoroutineWorker(context, workerParams) {

    override suspend fun doWork(): Result {
        dao.deleteNotesInTrash()
         return Result.success()
    }


}

app module:

@Module
@InstallIn(ApplicationComponent::class)
object AppModule {

    @Singleton
    @Provides
    fun getNotesDatabase(@ApplicationContext context: Context) =
        Room.databaseBuilder(context, NotesDatabase::class.java, NotesDatabase.DB_NAME).build()

    @Singleton
    @Provides
    fun getDoa(db: NotesDatabase) = db.notesDao()

}

application class:

@HiltAndroidApp
class App : Application(), Configuration.Provider {

    @Inject
    lateinit var workerFactory: HiltWorkerFactory

    override fun getWorkManagerConfiguration(): Configuration {
        return Configuration.Builder()
            .setWorkerFactory(workerFactory)
            .build()
    }


}

build.gradle (app):

 dependencies {

.......

 //Hilt
    implementation "com.google.dagger:hilt-android:2.28-alpha"
    kapt "com.google.dagger:hilt-android-compiler:2.28-alpha"
    
    //Hilt with workManager
    implementation 'androidx.hilt:hilt-work:1.0.0-alpha02'
    kapt 'androidx.hilt:hilt-compiler:1.0.0-alpha02'
}

build.gradle (project):

 dependencies {
        classpath 'com.android.tools.build:gradle:4.0.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    ............

        //Hilt
        classpath 'com.google.dagger:hilt-android-gradle-plugin:2.28-alpha'

        ..........
    }

Did I do anything wrong in this case? if yes please help me with it

Answer 1

According to this documentation, you need to paste this code into your AndroidManifest to get Hilt's WorkManager Inject working.

<provider
    android:name="androidx.work.impl.WorkManagerInitializer"
    android:authorities="${applicationId}.workmanager-init"
    tools:node="remove" />

I had the same problem as you some moment ago and this fixed it

Answer 2

The answer provided by @Attila works for WorkManager versions 2.6 and below.

For versions 2.6+, you need to remove the WorkManagerInitializer node as follows:

 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    android:exported="false"
    tools:node="merge">

    <meta-data
        android:name="androidx.work.WorkManagerInitializer"
        android:value="androidx.startup"
        tools:node="remove" />
 </provider>

The WorkManager documentation provides more information about this.

Answer 3

In case you're a dummy like me, don't forgot to include kapt 'androidx.hilt:hilt-compiler:1.0.0' to your dependencies.

You will get the same exception if the androidx hilt compiler extension is missing and you will also not get any build warnings or errors.

Answer 4

Since work version 2.6 it works using below androidmanifest.xml

AndroidManifest.xml

<provider
     android:name="androidx.startup.InitializationProvider"
     android:authorities="${applicationId}.androidx-startup"
     tools:node="remove">
</provider>

and in case of Worker class some annotation was changed. @HiltWorker, @AssistedInject

@HiltWorker
class RefreshWorker @AssistedInject constructor(
    @Assisted appContext: Context,
    @Assisted workerParams: WorkerParameters,
    val myRepository: MyRepository
) : CoroutineWorker(appContext, workerParams) {

    override suspend fun doWork(): Result {
        return Result.success()
    }

}

Developer site ( worker api ) https://developer.android.com/jetpack/androidx/releases/hilt

Replace @WorkerInject with @HiltWorker. @HiltWorker is now a type annotation and requires the usage of @AssistedInject in the constructor. (Ic2f15)

Developer site ( remove default worker initializer ) https://developer.android.com/topic/libraries/architecture/workmanager/advanced/custom-configuration#remove-default

remove the default initializer To provide your own configuration, you must first remove the default initializer. To do so, update AndroidManifest.xml using the merge rule tools:node="remove".

Since WorkManager 2.6, App Startup is used internally within WorkManager. To provide a custom initializer you need to remove the androidx.startup node.