MyRepository
class MyRepository #Inject constructor(
private val myDao: IMyDao
){
...
}
MyModule
#InstallIn(SingletonComponent::class)
#Module
class MyModule {
#Provides
fun provideMyRepository(MyDao: IMyDao): MyRepository{
return MyRepository(MyDao)
}
}
Use in Worker
class MyWorker(appContext: Context, workerParams: WorkerParameters) :
Worker(appContext, workerParams) {
private val myRepository: MyRepository =
EntryPointAccessors.fromApplication(appContext, MyRepository::class.java)
}
start worker in Application class.
but got error: java.lang.ClassCastException: Cannot cast com.freedom.android.DaggerMyApplication_HiltComponents_SingletonC$SingletonCImpl to com.freedom.android.MyRepository
I read the relevant documentation.But I don't want to use the interface, I just want the class to be provided.
Please tell me what is the problem.
In this case you need to use hilt worker
#HiltWorker class WokerName #AssistedInject constructor(
#Assisted appContext: Context,
#Assisted params: WorkerParameters,
myRepository: MyRepository): CoroutineWorker(appContext, params)
Go through all the links below you will get all the gradel dependency, how to use them etc..
https://developer.android.com/training/dependency-injection/hilt-jetpack#kotlin
https://developer.android.com/reference/androidx/hilt/work/HiltWorker
https://developer.android.com/guide/background/persistent/configuration/custom-configuration
https://developer.android.com/topic/libraries/app-startup
I have initiated a worker in my App class like below;
#HiltAndroidApp
class KutuphanemApplication:Application(),Configuration.Provider {
#Inject
lateinit var workerFactory: HiltWorkerFactory
override fun getWorkManagerConfiguration() =
Configuration.Builder()
.setMinimumLoggingLevel(android.util.Log.DEBUG)
.setWorkerFactory(workerFactory)
.build()
I want to inject a singleton dao into my worker class for update something in DB. So I am injecting dao like below;
#HiltWorker
class ClearImageNotInArchiveWorker #AssistedInject constructor(
#Assisted val appContext: Context,
#Assisted val workerParams: WorkerParameters,
private val kitapDao: KitapDao): CoroutineWorker(appContext, workerParams) {
override suspend fun doWork(): Result {...}
}
When I enquee this WorkManager class in App class , I am getting
WorkerFactory: Could not instantiate com.mesutemre.kutuphanem.job.ClearImageNotInArchiveWorker
error. But application is not crashing. Is there any problem about injecting dao in here?
Also my singleton dao;
#Singleton
#Provides
fun provideKitapDao(database: KutuphanemDatabase) = database.getKitapDao();
I solved the problem. I messed up hilt-compiler kapts. I have added
kapt("androidx.hilt:hilt-compiler:1.0.0")
into the gradle then I added
<provider
android:name="androidx.startup.InitializationProvider"
android:authorities="${applicationId}.androidx-startup"
tools:node="remove">
</provider>
into AndroidManifest.xml . Then the problem solved.
Hy
I recently migarted my projekt from dagger 2 to Hilt. Everything went well, but when I modified my WorkManager class, since my worker hasn't done anything.
In logcat I found this error message: WM-WorkerFactory: Could not instantiate hu.crm.crmapp.workmanager.SynchronizationWorker
java.lang.NoSuchMethodException: hu.crm.crmapp.workmanager.SynchronizationWorker. [class android.content.Context, class androidx.work.WorkerParameters]
First of all, I checked all of things, that I found in stackoverflow, so I deleted thw workmanager provider from manifest.
The Sync,and PrefManager dependies I also provided, but I don't copy that bunch of code here.
My Woker class:
#HiltWorker
class SynchronizationWorker #AssistedInject constructor(
private val sync: Sync,
private val prefManager: PrefManager,
#Assisted private val context: Context,
#Assisted workerParams: WorkerParameters
) : Worker(context, workerParams) {
private val countDownLatch = CountDownLatch(1)
override fun doWork(): Result {
val notificationHelper = NotificationHelper(context)
var workResult: Result = Result.success()
//doThings
}
My Application class:
#HiltAndroidApp
class CrmApp : Application(), Configuration.Provider {
#Inject
lateinit var workerFactory: HiltWorkerFactory
#Inject
lateinit var errorLogDao: ErrorLogDao
override fun attachBaseContext(base: Context?) {
super.attachBaseContext(base)
MultiDex.install(this)
}
override fun onCreate() {
super.onCreate()
BuildTypeInitializations.init(this)
}
override fun getWorkManagerConfiguration(): Configuration {
return Configuration.Builder()
.setWorkerFactory(workerFactory)
.build()
}
}
And there is the call of Worker class
val constraint =
Constraints.Builder()
.setRequiredNetworkType(NetworkType.CONNECTED).build()
val synchronizationWorker =
OneTimeWorkRequest.Builder(SynchronizationWorker::class.java)
.setConstraints(constraint)
.setBackoffCriteria(
BackoffPolicy.LINEAR,
OneTimeWorkRequest.MIN_BACKOFF_MILLIS,
TimeUnit.MILLISECONDS
)
.build()
WorkManager.getInstance(requireContext()).enqueue(synchronizationWorker)
Thanks for the help.
I encountered the same problem and error when I wanted to inject constructor parameters in the Workmanager with the Dagger-Hilt. Follow these steps to inject constructor parameters in the Workmanager with Hilt:
Step 1: Remove the default initializer from the AndroidManifest.xml:
<application>
<provider
android:name="androidx.work.impl.WorkManagerInitializer"
android:authorities="${applicationId}.workmanager-init"
tools:node="remove" />
</application>
(As you've stated, you have already done this part)
Step 2: In your Application class insert this code:
#HiltAndroidApp
class ImageSearchApplication : Application(), Configuration.Provider{
#Inject lateinit var workerFactory: MyWorkerFactory
override fun getWorkManagerConfiguration() =
Configuration.Builder()
.setMinimumLoggingLevel(android.util.Log.DEBUG)
.setWorkerFactory(workerFactory)
.build()
}
Step 3: Now create this class called MyWorkerFactory like this:
class MyWorkerFactory #Inject constructor (private val repository: UnsplashRepository) : WorkerFactory() {
override fun createWorker(
appContext: Context,
workerClassName: String,
workerParameters: WorkerParameters
): ListenableWorker? {
// This only handles a single Worker, please don’t do this!!
// See below for a better way using DelegatingWorkerFactory
return MyWorker(appContext, workerParameters, repository)
}
}
That's it! Note that, pass and inject all the parameters you need in the Worker class. I needed only my repository so I defined and injected it.
I am trying to use Dagger2 standard library with WorkManager. But in the examples on the internet they are using with dagger-android which I do not want. So, can you please suggest some solutions for this, so that I can use Dagger2, NOT dagger-android with WorkManager.
Thank you for your answer in advance!
This example using Kotlin.
class YourWorker(ctx: Context, params: WorkerParameters) : Worker(ctx, params) {
#Inject
lateinit var yourModel: YourModel
init {
getServiceComponent().inject(this) // or you create your component here and inject worker to it
}
}
#ServiceScope
#Component(
dependencies = {ApplicationComponent.class}
)
public interface ServiceComponent {
void inject(YourWorker worker);
}
You can inject a worker using Hilt.
Use #WorkerInject in the constructor of your worker. You must also annotate the Context and WorkerParameters dependencies with #Assisted:
class ExampleWorker #WorkerInject constructor(
#Assisted appContext: Context,
#Assisted workerParams: WorkerParameters,
workerDependency: WorkerDependency
) : Worker(appContext, workerParams) { ... }
And setup WorkManager configuration in your Application class:
#HiltAndroidApp
class ExampleApplication : Application(), Configuration.Provider {
#Inject lateinit var workerFactory: HiltWorkerFactory
override fun getWorkManagerConfiguration() =
Configuration.Builder()
.setWorkerFactory(workerFactory)
.build()
}
Reference: https://developer.android.com/training/dependency-injection/hilt-jetpack#workmanager
So from what I read, Dagger doesn't have support for inject in Worker yet. But there are some workarounds as people suggest. I have tried to do it a number of ways following examples online but none of them work for me.
When I don't try to inject anything into the Worker class, the code works fine, only that I can't do what I want because I need access to some DAOs and Services. If I use #Inject on those dependencies, the dependencies are either null or the worker never starts i.e the debugger doesn't even enter the Worker class.
For eg I tried doing this:
#Component(modules = {Module.class})
public interface Component{
void inject(MyWorker myWorker);
}
#Module
public class Module{
#Provides
public MyRepository getMyRepo(){
return new myRepository();
}
}
And in my worker
#Inject
MyRepository myRepo;
public MyWorker() {
DaggerAppComponent.builder().build().inject(this);
}
But then the execution never reaches the worker. If I remove the constructor, the myRepo dependency remains null.
I tried doing many other things but none work. Is there even a way to do this? Thanks!!
Overview
You need to look at WorkerFactory, available from 1.0.0-alpha09 onwards.
Previous workarounds relied on being able to create a Worker using the default 0-arg constructor, but as of 1.0.0-alpha10 that is no longer an option.
Example
Let's say that you have a Worker subclass called DataClearingWorker, and that this class needs a Foo from your Dagger graph.
class DataClearingWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {
lateinit var foo: Foo
override fun doWork(): Result {
foo.doStuff()
return Result.SUCCESS
}
}
Now, you can't just instantiate one of those DataClearingWorker instances directly. So you need to define a WorkerFactory subclass that can create one of them for you; and not just create one, but also set your Foo field too.
class DaggerWorkerFactory(private val foo: Foo) : WorkerFactory() {
override fun createWorker(appContext: Context, workerClassName: String, workerParameters: WorkerParameters): ListenableWorker? {
val workerKlass = Class.forName(workerClassName).asSubclass(Worker::class.java)
val constructor = workerKlass.getDeclaredConstructor(Context::class.java, WorkerParameters::class.java)
val instance = constructor.newInstance(appContext, workerParameters)
when (instance) {
is DataClearingWorker -> {
instance.foo = foo
}
// optionally, handle other workers
}
return instance
}
}
Finally, you need to create a DaggerWorkerFactory which has access to the Foo. You can do this in the normal Dagger way.
#Provides
#Singleton
fun workerFactory(foo: Foo): WorkerFactory {
return DaggerWorkerFactory(foo)
}
Disabling Default WorkManager Initialization
You'll also need to disable the default WorkManager initialization (which happens automatically) and initialize it manually.
How you do this depends on the version of androidx.work that you're using:
2.6.0 and onwards:
In AndroidManifest.xml, add:
<provider
android:name="androidx.startup.InitializationProvider"
android:authorities="YOUR_APP_PACKAGE.androidx-startup"
android:exported="false"
tools:node="merge">
<meta-data
android:name="androidx.work.WorkManagerInitializer"
android:value="androidx.startup"
tools:node="remove" />
</provider>
Pre 2.6.0:
In AndroidManifest.xml, add:
<provider
android:name="androidx.work.impl.WorkManagerInitializer"
android:authorities="YOUR_APP_PACKAGE.workmanager-init"
android:enabled="false"
android:exported="false"
tools:replace="android:authorities" />
Be sure to replace YOUR_APP_PACKAGE with your actual app's package. The <provider block above goes inside your <application tag.. so it's a sibling of your Activities, Services etc...
In your Application subclass, (or somewhere else if you prefer), you can manually initialize WorkManager.
#Inject
lateinit var workerFactory: WorkerFactory
private fun configureWorkManager() {
val config = Configuration.Builder()
.setWorkerFactory(workerFactory)
.build()
WorkManager.initialize(this, config)
}
2020/06 Update
Things become much easier with Hilt and Hilt for Jetpack.
With Hilt, all you have to do is
add annotation #HiltAndroidApp to your Application class
inject out-of-box HiltWorkerFactory in the field fo Application class
Implement interface Configuration.Provider and return the injected work factory in Step 2.
Now, change the annotation on the constructor of Worker from #Inject to #WorkerInject
class ExampleWorker #WorkerInject constructor(
#Assisted appContext: Context,
#Assisted workerParams: WorkerParameters,
someDependency: SomeDependency // your own dependency
) : Worker(appContext, workerParams) { ... }
That's it!
(also, don't forget to disable default work manager initialization)
===========
Old solution
As of version 1.0.0-beta01, here is an implementation of Dagger injection with WorkerFactory.
The concept is from this article: https://medium.com/#nlg.tuan.kiet/bb9f474bde37 and I just post my own implementation of it step by step(in Kotlin).
===========
What's this implementation trying to achieve is:
Every time you want to add a dependency to a worker, you put the dependency in the related worker class
===========
1. Add an interface for all worker's factory
IWorkerFactory.kt
interface IWorkerFactory<T : ListenableWorker> {
fun create(params: WorkerParameters): T
}
2. Add a simple Worker class with a Factory which implements IWorkerFactory and also with the dependency for this worker
HelloWorker.kt
class HelloWorker(
context: Context,
params: WorkerParameters,
private val apiService: ApiService // our dependency
): Worker(context, params) {
override fun doWork(): Result {
Log.d("HelloWorker", "doWork - fetchSomething")
return apiService.fetchSomething() // using Retrofit + RxJava
.map { Result.success() }
.onErrorReturnItem(Result.failure())
.blockingGet()
}
class Factory #Inject constructor(
private val context: Provider<Context>, // provide from AppModule
private val apiService: Provider<ApiService> // provide from NetworkModule
) : IWorkerFactory<HelloWorker> {
override fun create(params: WorkerParameters): HelloWorker {
return HelloWorker(context.get(), params, apiService.get())
}
}
}
3. Add a WorkerKey for Dagger's multi-binding
WorkerKey.kt
#MapKey
#Target(AnnotationTarget.FUNCTION)
#Retention(AnnotationRetention.RUNTIME)
annotation class WorkerKey(val value: KClass<out ListenableWorker>)
4. Add a Dagger module for multi-binding worker (actually multi-binds the factory)
WorkerModule.kt
#Module
interface WorkerModule {
#Binds
#IntoMap
#WorkerKey(HelloWorker::class)
fun bindHelloWorker(factory: HelloWorker.Factory): IWorkerFactory<out ListenableWorker>
// every time you add a worker, add a binding here
}
5. Put the WorkerModule into AppComponent. Here I use dagger-android to construct the component class
AppComponent.kt
#Singleton
#Component(modules = [
AndroidSupportInjectionModule::class,
NetworkModule::class, // provides ApiService
AppModule::class, // provides context of application
WorkerModule::class // <- add WorkerModule here
])
interface AppComponent: AndroidInjector<App> {
#Component.Builder
abstract class Builder: AndroidInjector.Builder<App>()
}
6. Add a custom WorkerFactory to leverage the ability of creating worker since the release version of 1.0.0-alpha09
DaggerAwareWorkerFactory.kt
class DaggerAwareWorkerFactory #Inject constructor(
private val workerFactoryMap: Map<Class<out ListenableWorker>, #JvmSuppressWildcards Provider<IWorkerFactory<out ListenableWorker>>>
) : WorkerFactory() {
override fun createWorker(
appContext: Context,
workerClassName: String,
workerParameters: WorkerParameters
): ListenableWorker? {
val entry = workerFactoryMap.entries.find { Class.forName(workerClassName).isAssignableFrom(it.key) }
val factory = entry?.value
?: throw IllegalArgumentException("could not find worker: $workerClassName")
return factory.get().create(workerParameters)
}
}
7. In Application class, replace WorkerFactory with our custom one:
App.kt
class App: DaggerApplication() {
override fun onCreate() {
super.onCreate()
configureWorkManager()
}
override fun applicationInjector(): AndroidInjector<out DaggerApplication> {
return DaggerAppComponent.builder().create(this)
}
#Inject lateinit var daggerAwareWorkerFactory: DaggerAwareWorkerFactory
private fun configureWorkManager() {
val config = Configuration.Builder()
.setWorkerFactory(daggerAwareWorkerFactory)
.build()
WorkManager.initialize(this, config)
}
}
8. Don't forget to disable default work manager initialization
AndroidManifest.xml
<provider
android:name="androidx.work.impl.WorkManagerInitializer"
android:authorities="${applicationId}.workmanager-init"
android:enabled="false"
android:exported="false"
tools:replace="android:authorities" />
That's it.
Every time you want to add a dependency to a worker, you put the dependency in the related worker class (like HelloWorker here).
Every time you want to add a worker, implement the factory in the worker class and add the worker's factory to WorkerModule for multi-binding.
For more detail, like using AssistedInject to reduce boilerplate codes, please refer to the article I mentioned at beginning.
I use Dagger2 Multibindings to solve this problem.
The similar approach is used to inject ViewModel objects (it's described well here). Important difference from view model case is the presence of Context and WorkerParameters arguments in Worker constructor. To provide these arguments to worker constructor intermediate dagger component should be used.
Annotate your Worker's constructor with #Inject and provide your desired dependency as constructor argument.
class HardWorker #Inject constructor(context: Context,
workerParams: WorkerParameters,
private val someDependency: SomeDependency)
: Worker(context, workerParams) {
override fun doWork(): Result {
// do some work with use of someDependency
return Result.SUCCESS
}
}
Create custom annotation that specifies the key for worker multibound map entry.
#MustBeDocumented
#Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER)
#Retention(AnnotationRetention.RUNTIME)
#MapKey
annotation class WorkerKey(val value: KClass<out Worker>)
Define worker binding.
#Module
interface HardWorkerModule {
#Binds
#IntoMap
#WorkerKey(HardWorker::class)
fun bindHardWorker(worker: HardWorker): Worker
}
Define intermediate component along with its builder. The component must have the method to get workers map from dependency graph and contain worker binding module among its modules. Also the component must be declared as a subcomponent of its parent component and parent component must have the method to get the child component's builder.
typealias WorkerMap = MutableMap<Class<out Worker>, Provider<Worker>>
#Subcomponent(modules = [HardWorkerModule::class])
interface WorkerFactoryComponent {
fun workers(): WorkerMap
#Subcomponent.Builder
interface Builder {
#BindsInstance
fun setParameters(params: WorkerParameters): Builder
#BindsInstance
fun setContext(context: Context): Builder
fun build(): WorkerFactoryComponent
}
}
// parent component
#ParentComponentScope
#Component(modules = [
//, ...
])
interface ParentComponent {
// ...
fun workerFactoryComponent(): WorkerFactoryComponent.Builder
}
Implement WorkerFactory. It will create the intermediate component, get workers map, find the corresponding worker provider and construct the requested worker.
class DIWorkerFactory(private val parentComponent: ParentComponent) : WorkerFactory() {
private fun createWorker(workerClassName: String, workers: WorkerMap): ListenableWorker? = try {
val workerClass = Class.forName(workerClassName).asSubclass(Worker::class.java)
var provider = workers[workerClass]
if (provider == null) {
for ((key, value) in workers) {
if (workerClass.isAssignableFrom(key)) {
provider = value
break
}
}
}
if (provider == null)
throw IllegalArgumentException("no provider found")
provider.get()
} catch (th: Throwable) {
// log
null
}
override fun createWorker(appContext: Context,
workerClassName: String,
workerParameters: WorkerParameters) = parentComponent
.workerFactoryComponent()
.setContext(appContext)
.setParameters(workerParameters)
.build()
.workers()
.let { createWorker(workerClassName, it) }
}
Initialize a WorkManager manually with custom worker factory (it must be done only once per process). Don't forget to disable auto initialization in manifest.
manifest:
<provider
android:name="androidx.work.impl.WorkManagerInitializer"
android:authorities="${applicationId}.workmanager-init"
android:exported="false"
tools:node="remove" />
Application onCreate:
val configuration = Configuration.Builder()
.setWorkerFactory(DIWorkerFactory(parentComponent))
.build()
WorkManager.initialize(context, configuration)
Use worker
val request = OneTimeWorkRequest.Builder(workerClass).build(HardWorker::class.java)
WorkManager.getInstance().enqueue(request)
Watch this talk for more information on WorkManager features.
In WorkManager alpha09 there is a new WorkerFactory that you can use to initialize the Worker the way you want to.
Use the new Worker constructor which takes in an ApplicationContext and WorkerParams.
Register an implementation of WorkerFactory via Configuration.
Create a configuration and register the newly created WorkerFactory.
Initialize WorkManager with this configuration (while removing the ContentProvider which initializes WorkManager on your behalf).
You need to do the following:
public DaggerWorkerFactory implements WorkerFactory {
#Nullable Worker createWorker(
#NonNull Context appContext,
#NonNull String workerClassName,
#NonNull WorkerParameters workerParameters) {
try {
Class<? extends Worker> workerKlass = Class.forName(workerClassName).asSubclass(Worker.class);
Constructor<? extends Worker> constructor =
workerKlass.getDeclaredConstructor(Context.class, WorkerParameters.class);
// This assumes that you are not using the no argument constructor
// and using the variant of the constructor that takes in an ApplicationContext
// and WorkerParameters. Use the new constructor to #Inject dependencies.
Worker instance = constructor.newInstance(appContext,workerParameters);
return instance;
} catch (Throwable exeption) {
Log.e("DaggerWorkerFactory", "Could not instantiate " + workerClassName, e);
// exception handling
return null;
}
}
}
// Create a configuration
Configuration configuration = new Configuration.Builder()
.setWorkerFactory(new DaggerWorkerFactory())
.build();
// Initialize WorkManager
WorkManager.initialize(context, configuration);