Kotlin + Dagger 2：不会生成 Dagger* 文件

Question

I started using Kotlin and Dagger 2 together for the first time. I assumed everything is the same as in Java, but apparently, not quite. Dagger won't generate Dagger*files for me. Here is my code:

Components:

@PerActivity
@Subcomponent(modules = arrayOf(ApplicationModule::class))
interface ActivityComponent {
    fun inject(app: OneAccountApplication)
}

---

@Singleton
@Component(modules = arrayOf(ApplicationModule::class))
interface ApplicationComponent {

fun inject(syncService: SyncService)
@ApplicationContext fun context(): Context
fun application(): Application
fun ribotsService(): OneAccountService
fun preferencesHelper(): PreferencesHelper
fun databaseHelper(): DatabaseHelper
fun dataManager(): DataManager
}

---

@ConfigPersistent
@Component(dependencies = arrayOf(ApplicationComponent::class))
interface ConfigPersistentComponent {
    fun activityComponent(activityModule: ActivityModule): ActivityComponent
}

---

Modules:

@Module
class ActivityModule(private val mActivity: Activity) {

    @Provides
    internal fun provideActivity() = mActivity

    @Provides
    @ActivityContext
    internal fun providesContext() = mActivity
}

---

@Module
class ApplicationModule(val mApplication: Application) {

    @Provides @Singleton
    internal fun provideApplication() = mApplication

    @Provides
    @ApplicationContext
    internal fun provideContext() = mApplication

    @Provides
    @Singleton
    internal fun provideOneAccountService() = OneAccountService.Creator.newOneAccountService()
}

---

Scope Annotations:

@Qualifier
@Retention(AnnotationRetention.RUNTIME)
annotation class ActivityContext

---

@Qualifier
@Retention(AnnotationRetention.RUNTIME)
annotation class ApplicationContext

---

@Scope
@Retention(AnnotationRetention.RUNTIME)
annotation class ConfigPersistent

---

@Scope
@Retention(AnnotationRetention.RUNTIME)
annotation class PerActivity

---

This is basically my whole DI system which I was using in my java code successfully. But with Kotlin, for some reason it does not work. I have also added: apply plugin: 'kotlin-kapt' to gradle.build like:

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'

And in dependencies I have:

dependencies {

    final DAGGER_VERSION = '2.8'
    def daggerCompiler = "com.google.dagger:dagger-compiler:$DAGGER_VERSION"
    annotationProcessor daggerCompiler
    testAnnotationProcessor daggerCompiler
    androidTestAnnotationProcessor daggerCompiler
    compile  "com.google.dagger:dagger:$DAGGER_VERSION"
}
kapt {
    generateStubs = true
}

Basically, this it https://github.com/ribot/android-boilerplate transformed into Kotlin.

Answer 1

Kotlin works with kapt instead of the annotationProcessor from the Android plugin.

You need to include and use the following in your build.gradle file:

kapt {
    generateStubs = true
}
dependencies {
    // ...
    kapt daggerCompiler
}

More detailed instructions can also be found here: Dagger and Kotlin

Answer 2

I use this gradle and is working fine

buildscript {

  val kotlinVersion = "1.4.20"

  repositories {
    mavenCentral()
  }
  dependencies {
    classpath ("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion")
  }
}
plugins {
  kotlin("jvm") version "1.5.30"
  kotlin("kapt") version "1.5.30"
  application
}


repositories {
  mavenCentral()
  google()
}

application {
  mainClass.set("dp.strategy.MiniDuckSimulator")
}

java {
  sourceCompatibility = JavaVersion.VERSION_1_8
  targetCompatibility = JavaVersion.VERSION_1_8
}


dependencies {
  implementation ("com.google.dagger:dagger:2.39.1")
  kapt ("com.google.dagger:dagger-compiler:2.39.1")
}

kapt {
  mapDiagnosticLocations = true // include the Kotlin files into error reports
}

kapt {
  javacOptions {
    // Increase the max count of errors from annotation processors.
    // Default is 100.
    option("-Xmaxerrs", 500)
  }
}