Develop Reference

error: [Hilt] Null element: java.lang.NullPointerException: Null element [Hilt]

I was writing unit tests for my room db operations, everything was working great but, I decided to write and inject the DataBaseBuilder within TestAppModule using Hilt, but seems like I am getting the following error when i run the tests. I also created a custom HiltRunnerClass and used it in gradle as testInstrumentationRunner "com.rimapps.wisetest.HiltTestRunner"
here is full error
error: [Hilt]
Null element: java.lang.NullPointerException: Null element
at dagger.hilt.processor.internal.root.AutoValue_Root.<init>(AutoValue_Root.java:19)
at dagger.hilt.processor.internal.root.Root.createDefaultRoot(Root.java:46)
at
[Hilt] Processing did not complete. See error above for details.
1 error
here is the code
HiltTestRunner.kt
class HiltTestRunner:AndroidJUnitRunner() {
override fun newApplication(
cl: ClassLoader?,
className: String?,
context: Context?
): Application {
return super.newApplication(cl, HiltTestApplication::class.java.name, context)
}
}
NewsArticleDaoTest.kt
#RunWith(AndroidJUnit4::class)
#SmallTest
#HiltAndroidTest
class NewsArticleDaoTest{
#get:Rule
var hiltRule = HiltAndroidRule(this)
#get:Rule
var instantTaskExecutorRule = InstantTaskExecutorRule()
#Inject
#Named("test_db")
lateinit var database: NewsArticleDatabase
//private lateinit var database: NewsArticleDatabase
private lateinit var dao: NewsArticleDao
#Before
fun setup(){
hiltRule.inject()
dao = database.newsArticleDao()
// database = Room.inMemoryDatabaseBuilder(
// ApplicationProvider.getApplicationContext(),
// NewsArticleDatabase::class.java
// ).allowMainThreadQueries().build()
dao = database.newsArticleDao()
}
#After
fun teardown(){
database.close()
}
#Test
fun insertNewsArticle() = runTest {
val testArticle = NewsArticle("Time traveller shares footage from three weeks in the future showing who wins the World Cup","https://www.ladbible.com/sport/time-traveller-who-wins-world-cup-2022-20221128","https://images.ladbible.com/resize?type=webp&quality=70&width=671&fit=contain&gravity=null&dpr=2&url=https://eu-images.contentstack.com/v3/assets/bltcd74acc1d0a99f3a/bltb6064933a4b82b9c/6384c84adb8e364b186bfb6c/Most_prolific_speed_camera_in_the_UK_has_caught_almost_50_000_drivers_this_year_(42).png")
val testItem = listOf(testArticle)
dao.insertArticles(testItem)
val testFeed = NewsFeed(testArticle.url)
val feedTestItem = listOf(testFeed)
dao.insertNewsFeed(feedTestItem)
val allNewsArticles = dao.getAllNewsArticles().first()
assertThat(allNewsArticles).contains(testArticle)
}
#Test
fun deleteAllArticles()= runTest {
val testArticle = NewsArticle("Time traveller claims discovery of mysterious sea creature will change world","https://www.dailystar.co.uk/news/weird-news/time-traveller-claims-discovery-mysterious-28766022","https://i2-prod.dailystar.co.uk/incoming/article28766081.ece/ALTERNATES/s615b/1_A-SELF-proclaimed-time-traveller-from-2198-claims-experts-will-soon-make-a-chilling-ocean-discovery.jpg")
val testItem = listOf(testArticle)
dao.insertArticles(testItem)
val testFeed = NewsFeed(testArticle.url)
val feedTestItem = listOf(testFeed)
dao.insertNewsFeed(feedTestItem)
dao.deleteAllNewsFeed()
val allArticles = dao.getAllNewsArticles().first()
assertThat(allArticles).doesNotContain(testArticle)
}
}
TestAppModule.kt
#Module
#InstallIn(SingletonComponent::class)
object TestAppModule {
#Provides
#Named("test_db")
fun provideInMemoryDb(#ApplicationContext context: Context) =
Room.inMemoryDatabaseBuilder(context,NewsArticleDatabase::class.java )
.allowMainThreadQueries()
.build()
}
gladle(app)
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
id 'dagger.hilt.android.plugin'
id 'kotlin-parcelize'
id 'androidx.navigation.safeargs'
}
android {
compileSdkVersion 33
buildToolsVersion "30.0.3"
defaultConfig {
applicationId "com.rimapps.wisetest"
minSdkVersion 21
targetSdkVersion 33
versionCode 1
versionName "1.0"
//testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
testInstrumentationRunner "com.rimapps.wisetest.HiltTestRunner"
buildConfigField("String", "NEWS_API_ACCESS_KEY", news_api_access_key)
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
buildFeatures {
viewBinding true
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
freeCompilerArgs += "-Xopt-in=androidx.paging.ExperimentalPagingApi"
freeCompilerArgs += "-Xopt-in=kotlinx.coroutines.ExperimentalCoroutinesApi"
}
}
dependencies {
implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
implementation 'androidx.core:core-ktx:1.9.0'
implementation 'androidx.appcompat:appcompat:1.5.1'
//noinspection GradleDependency
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation 'androidx.navigation:navigation-fragment-ktx:2.5.3'
implementation 'androidx.navigation:navigation-ui-ktx:2.5.3'
testImplementation 'org.junit.jupiter:junit-jupiter'
androidTestImplementation 'androidx.test.ext:junit:1.1.4'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0'
// Glide
implementation "com.github.bumptech.glide:glide:4.14.2"
// Dagger Hilt
implementation "com.google.dagger:hilt-android:2.44.2"
kapt "com.google.dagger:hilt-android-compiler:2.44.2"
// Coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4'
// Retrofit + GSON
implementation "com.squareup.retrofit2:retrofit:2.9.0"
implementation "com.squareup.retrofit2:converter-gson:2.9.0"
// Room
implementation "androidx.room:room-runtime:2.5.0-rc01"
kapt "androidx.room:room-compiler:2.5.0-rc01"
implementation "androidx.room:room-ktx:2.5.0-rc01"
// SwipeRefreshLayout
implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.1.0"
// Paging 3
implementation "androidx.paging:paging-runtime-ktx:3.2.0-alpha03"
// Fragment
implementation 'androidx.fragment:fragment-ktx:1.6.0-alpha04'
// Local Unit Tests
implementation "androidx.test:core:1.5.0"
testImplementation "junit:junit:4.13.2"
testImplementation "org.hamcrest:hamcrest-all:1.3"
testImplementation "androidx.arch.core:core-testing:2.1.0"
testImplementation "org.robolectric:robolectric:4.3.1"
testImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.4"
testImplementation "com.google.truth:truth:1.0.1"
testImplementation "org.mockito:mockito-core:3.4.6"
// Instrumented Unit Tests
androidTestImplementation "junit:junit:4.13.2"
androidTestImplementation "org.mockito:mockito-android:2.25.0"
androidTestImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.4"
androidTestImplementation "androidx.arch.core:core-testing:2.1.0"
androidTestImplementation "com.google.truth:truth:1.0.1"
androidTestImplementation 'androidx.test.ext:junit:1.1.4'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0'
androidTestImplementation "org.mockito:mockito-core:3.4.6"
androidTestImplementation 'com.google.dagger:hilt-android-testing:2.28-alpha'
kaptAndroidTest 'com.google.dagger:hilt-android-compiler:2.44.2'
debugImplementation "androidx.fragment:fragment-testing:1.5.5"
}
kapt {
correctErrorTypes true
}
gradle(project)
buildscript {
ext.kotlin_version = "1.7.20"
repositories {
google()
mavenCentral()
}
dependencies {
classpath 'com.android.tools.build:gradle:7.3.1'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
classpath "androidx.navigation:navigation-safe-args-gradle-plugin:2.6.0-alpha04"
classpath "com.google.dagger:hilt-android-gradle-plugin:2.44.2"
}
}
allprojects {
repositories {
google()
mavenCentral()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

Creating a ViewModel causes the app to crash. (Kotlin/Android Studio)

I have been following a tutorial from Geeks for Geeks on how to make a simple note app for Android. I've practically copied to code word-by-word (except for a minor fix in the gradle file as advised from a Stack Overflow post and a comment in the YouTube comment section), yet the app crashes every time I open it even after clearing all the caches and rebuilding the project.
Links:
https://www.geeksforgeeks.org/how-to-build-a-simple-note-android-app-using-mvvm-and-room-database/
https://www.youtube.com/watch?v=D2F5t-phP04
Now, I know the problem with the code stems from the below command line.
viewModel = ViewModelProvider(
this,
ViewModelProvider.AndroidViewModelFactory.getInstance(application)
).get(NoteViewModel::class.java)
Every time I include the above line and launch the app, the app crashes, and my phone cannot open it. Commenting out the above line and the code below it allows the app to be opened without an issue.
(App gradle)
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'kotlin-kapt'
}
android {
compileSdk 32
defaultConfig {
applicationId "com.example.notepractice"
minSdk 26
targetSdk 32
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
packagingOptions {
exclude 'META-INF/atomicfu.kotlin_module'
}
kotlinOptions {
jvmTarget = '1.8'
}
buildFeatures {
viewBinding true
}
}
dependencies {
implementation "androidx.appcompat:appcompat:$rootProject.appCompatVersion"
implementation "androidx.activity:activity-ktx:$rootProject.activityVersion"
// Dependencies for working with Architecture components
// You'll probably have to update the version numbers in build.gradle (Project)
implementation 'androidx.fragment:fragment-ktx:1.1.0'
// Room components
implementation "androidx.room:room-ktx:$rootProject.roomVersion"
annotationProcessor "androidx.room:room-compiler:$rootProject.roomVersion"
androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"
// Lifecycle components
implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.2.0"
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0"
implementation "androidx.lifecycle:lifecycle-common-java8:$rootProject.lifecycleVersion"
// Kotlin components
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
api "org.jetbrains.kotlinx:kotlinx-coroutines-core:$rootProject.coroutines"
api "org.jetbrains.kotlinx:kotlinx-coroutines-android:$rootProject.coroutines"
// UI
implementation "androidx.constraintlayout:constraintlayout:$rootProject.constraintLayoutVersion"
implementation "com.google.android.material:material:$rootProject.materialVersion"
// Testing
testImplementation "junit:junit:$rootProject.junitVersion"
androidTestImplementation "androidx.arch.core:core-testing:$rootProject.coreTestingVersion"
androidTestImplementation ("androidx.test.espresso:espresso-core:$rootProject.espressoVersion", {
exclude group: 'com.android.support', module: 'support-annotations'
})
androidTestImplementation "androidx.test.ext:junit:$rootProject.androidxJunitVersion"
}
(Project gradle)
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
ext.kotlin_version = "1.5.31"
repositories {
google()
mavenCentral()
}
dependencies {
classpath "com.android.tools.build:gradle-api:7.2.1"
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
}
}
plugins {
id 'com.android.application' version '7.2.0' apply false
id 'com.android.library' version '7.2.0' apply false
id 'org.jetbrains.kotlin.android' version '1.7.10' apply false
}
allprojects {
repositories {
google()
mavenCentral()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
/*
ext {
activityVersion = '1.4.0'
appCompatVersion = '1.4.0'
constraintLayoutVersion = '2.1.2'
coreTestingVersion = '2.1.0'
coroutines = '1.5.2'
lifecycleVersion = '2.4.0'
materialVersion = '1.4.0'
roomVersion = '2.3.0'
// testing
junitVersion = '4.13.2'
espressoVersion = '3.4.0'
androidxJunitVersion = '1.1.3'
}
*/
ext {
activityVersion = '1.2.3'
appCompatVersion = '1.3.0'
constraintLayoutVersion = '2.0.4'
coreTestingVersion = '2.1.0'
coroutines = '1.5.0'
lifecycleVersion = '2.3.1'
materialVersion = '1.3.0'
roomVersion = '2.3.0'
// testing
junitVersion = '4.13.2'
espressoVersion = '3.1.0'
androidxJunitVersion = '1.1.2'
}
(Main Activity)
package com.example.notepractice
import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.activity.viewModels
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.google.android.material.floatingactionbutton.FloatingActionButton
import java.util.*
class MainActivity : AppCompatActivity(), NoteClickInterface, NoteClickDeleteInterface {
lateinit var viewModel: NoteViewModel
lateinit var notesRV: RecyclerView
lateinit var addFAB: FloatingActionButton
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
notesRV = findViewById(R.id.RVNotes)
addFAB = findViewById(R.id.FABAddNote)
notesRV.layoutManager = LinearLayoutManager(this)
val noteRVAdapter = NoteRVAdapter(this, this, this)
notesRV.adapter = noteRVAdapter
viewModel = ViewModelProvider(
this,
ViewModelProvider.AndroidViewModelFactory.getInstance(application)
).get(NoteViewModel::class.java)
/*
viewModel.allNotes.observe(this, Observer { list ->
list?.let {
noteRVAdapter.updateList(it)
}
})
addFAB.setOnClickListener {
val intent = Intent(this#MainActivity, AddEditNoteActivity::class.java)
startActivity(intent)
this.finish()
}
*/
}
override fun onNoteClick(note: Note) {
val intent = Intent(this#MainActivity, AddEditNoteActivity::class.java)
intent.putExtra("noteType", "Edit")
intent.putExtra("noteTitle", note.noteTitle)
intent.putExtra("noteDescription", note.noteDescription)
intent.putExtra("noteId", note.id)
startActivity(intent)
}
override fun onDeleteIconClick(note: Note) {
viewModel.deleteNote(note)
Toast.makeText(this, "${note.noteTitle} Deleted", Toast.LENGTH_LONG).show()
}
}
(ViewModel)
package com.example.notepractice
import android.app.Application
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.LiveData
import androidx.lifecycle.viewModelScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
class NoteViewModel(application: Application): AndroidViewModel(application) {
val allNotes: LiveData<List<Note>>
val repository: NoteRepository
init {
val dao = NoteDatabase.getDatabase(application).getNotesDao()
repository = NoteRepository(dao)
allNotes = repository.allNotes
}
fun deleteNote (note: Note) = viewModelScope.launch(Dispatchers.IO) {
repository.delete(note)
}
fun updateNote(note: Note) = viewModelScope.launch(Dispatchers.IO) {
repository.update(note)
}
fun addNote(note: Note) = viewModelScope.launch(Dispatchers.IO) {
repository.insert(note)
}
}
I'd like to end my question post with an actual question, but I am very inexperienced and cannot specify the problem. What would be the correct way to set up a ViewModel in Android with Kotlin?

Try initialising NoteViewModel like this inside your Activity.
private val viewModel: NoteViewModel by lazy {
ViewModelProvider(this).get(NoteViewModel::class.java)
}

Cannot create an instance of viewmodel class with hilt

I am trying to create MVVM app using Openweathermap API and hilt. I tried to inject my repository into my viewmodel primary constractor and creating a ViewModelFactory class, in order to pass the parameters from viewmodel class to my main activity class it did not work with 'by viewmodels()' itself. Sadly it did not work and I am getting the following message "has no zero argument constructor". It worth to mention that I also tried to inject the repository into my secondary constractor.
This is my MainActivity
#AndroidEntryPoint
class MainActivity
#Inject constructor(var repository:WeatherRepositoryInterface) : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
private lateinit var previewAdapter: PreviewAdapter
lateinit var viewModel:WeatherViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
initViewItems()
}
fun initViewItems() {
viewModel= ViewModelProvider(this#MainActivity,FactoryViewModel(application,repository))[WeatherViewModel::class.java]
binding.recyclerview.apply {
layoutManager = LinearLayoutManager(this#MainActivity)
previewAdapter = PreviewAdapter(viewModel.loadCities().value!!)
previewAdapter.let {
it.setOnItemClickListener(object: OnClickInterface{
override fun onClickItem(position: Int) {
var intent=Intent(this#MainActivity,DetailActivity::class.java)
intent.putExtra("name",viewModel.loadCities().value!![position].cityName)
intent.putExtra("img",viewModel.loadCities().value!![position].cityImg)
startActivity(intent)
}
})
}
adapter = previewAdapter
}
}
}
My ViewModel class
#HiltViewModel
class WeatherViewModel #Inject constructor(application: Application, var repository: WeatherRepositoryInterface)
: AndroidViewModel(application) ,LifecycleObserver{
companion object{
private val VIEWMODEL_STRING="WeatherViewModel.class"
}
private var list: MutableLiveData<List<Preview>> = MutableLiveData()
fun getCityInfo(q:String) =
liveData(Dispatchers.IO){
emit(com.example.yourweatherapp.Resources.Resource.loading(data = null))
try {
emit(com.example.yourweatherapp.Resources.Resource.success(data = repository.getWeather(q=q)))
} catch (e: Exception) {
emit(e.message?.let { com.example.yourweatherapp.Resources.Resource.error(data = null, message = it) })
e.message?.let { Log.e(VIEWMODEL_STRING, it) }
}
}
fun loadCities():MutableLiveData<List<Preview>>{
list.value= listOf(
Preview(
CityList.santorini,
CityList.santoriniImg),
Preview(CityList.bern,
CityList.bernImg),
Preview(CityList.venice,
CityList.veniceImg),
Preview("",CityList.myLocationImg)
)
return list
}
}
My ViewModelFactory class:
class FactoryViewModel(
var application:Application,
var repository: WeatherRepositoryInterface
): ViewModelProvider.NewInstanceFactory() {
override fun <T : ViewModel> create(modelClass: Class<T>): T =
WeatherViewModel(application,repository) as T
}
My Gradle dependency file:
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'kotlin-kapt'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.example.yourweatherapp"
minSdk 21
targetSdk 31
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildFeatures {
dataBinding = true
viewBinding = true
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.4.0'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.2'
implementation 'androidx.navigation:navigation-fragment-ktx:2.4.0'
implementation 'androidx.navigation:navigation-ui-ktx:2.4.0'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
implementation "com.squareup.retrofit2:converter-gson:2.9.0"
implementation "com.squareup.retrofit2:retrofit:2.9.0"
implementation("androidx.cardview:cardview:1.0.0")
implementation 'com.github.bumptech.glide:glide:4.12.0'
implementation("androidx.cardview:cardview:1.0.0")
implementation("androidx.recyclerview:recyclerview:1.2.1")
// implementation ("androidx.lifecycle:lifecycle-livedata:2.5.0-alpha01")
//http3
implementation(platform("com.squareup.okhttp3:okhttp-bom:4.9.3"))
implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.5.0-alpha01"
implementation "androidx.activity:activity-ktx:1.1.0"
implementation("com.squareup.okhttp3:okhttp")
implementation("com.squareup.okhttp3:logging-interceptor")
//lifecycle
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.4.0"
implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:2.4.0")
implementation("androidx.lifecycle:lifecycle-viewmodel-compose:2.4.0")
kapt("androidx.lifecycle:lifecycle-compiler:2.5.0-alpha01")
implementation("androidx.lifecycle:lifecycle-common-java8:2.5.0-alpha01")
implementation("androidx.lifecycle:lifecycle-service:2.5.0-alpha01")
//fragment
implementation("androidx.fragment:fragment-ktx:1.4.1")
implementation("androidx.navigation:navigation-fragment-ktx:2.4.1")
implementation("androidx.navigation:navigation-ui-ktx:2.4.1")
//hilt dagger
implementation("com.google.dagger:hilt-android:2.38.1")
kapt("com.google.dagger:hilt-android-compiler:2.38.1")
//implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.4.2"
implementation 'androidx.hilt:hilt-navigation-compose:1.0.0'
implementation 'androidx.hilt:hilt-navigation-compose:1.0.0'
implementation 'androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03'
kapt 'androidx.hilt:hilt-compiler:1.0.0'
}
kapt {
javacOptions {
// These options are normally set automatically via the Hilt Gradle plugin, but we
// set them manually to workaround a bug in the Kotlin 1.5.20
option("-Adagger.fastInit=ENABLED")
option("-Adagger.hilt.android.internal.disableAndroidSuperclassValidation=true")
}
}

Just remove this line from your dependencies:
implementation 'androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03'

I found this in migrations doc and solved the issue for my case:
Remove this line from gradle:
implementation 'androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03'
I'm using latest versions of all dependencies, make sure to check and apply all related and necessary migrations

Can't use suspend function in RoomDB Dao

What is going on with RoomDB and Kotlin coroutines? I am trying, again and again, to use suspend function in Room Dao but every time it shows an error. I even follow the android codelabs example. But it shows an error again. the app doesn't even build if I write suspend in Dao. But if I remove suspend keyword it builds successfully.
It shows the error below:
error: Type of the parameter must be a class annotated with #Entity or a collection/array of it.
kotlin.coroutines.Continuation<? super kotlin.Unit> continuation);
My Entity:
import androidx.room.Entity
import androidx.room.PrimaryKey
#Entity(tableName = "vocabulary")
class Vocabulary(
#PrimaryKey(autoGenerate = true)
val vocabularyId: Long,
val word: String,
val meaning: String,
val definition: String,
val example: String,
val partsOfSpeech: String,
val synonyms: String,
val antonyms: String,
val phonetics: String,
val folderId: Long,
val isLearned: Int
)
My Dao:
import androidx.room.Dao
import androidx.room.Insert
import androidx.room.OnConflictStrategy
#Dao
interface VocabuilderDao {
#Insert(onConflict = OnConflictStrategy.IGNORE)
suspend fun insertVocab(vocabulary: Vocabulary)
}
My Database class:
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
#Database(entities = [Vocabulary::class], version = 1, exportSchema = false)
public abstract class VocabuilderRoomDb : RoomDatabase(){
abstract fun vocabuilderDao(): VocabuilderDao
companion object{
#Volatile
private var INSTANCE: VocabuilderRoomDb? = null
fun getRoomDatabase(context: Context): VocabuilderRoomDb{
return INSTANCE ?: synchronized(this){
val instance = Room.databaseBuilder(
context.applicationContext,
VocabuilderRoomDb::class.java,
"vocabuilder_roomdb"
).build()
INSTANCE = instance
instance
}
}
}
}
My build.gradle (project level):
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
ext.kotlin_version = '1.6.0'
repositories {
google()
mavenCentral()
}
dependencies {
classpath "com.android.tools.build:gradle:7.0.2"
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.0"
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
ext {
activityVersion = '1.2.3'
appCompatVersion = '1.3.0'
constraintLayoutVersion = '2.0.4'
coreTestingVersion = '2.1.0'
coroutines = '1.5.0'
lifecycleVersion = '2.3.1'
materialVersion = '1.3.0'
roomVersion = '2.3.0'
// testing
junitVersion = '4.13.2'
espressoVersion = '3.1.0'
androidxJunitVersion = '1.1.2'
}
task clean(type: Delete) {
delete rootProject.buildDir
}
My build.gradle(module):
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.domesoft.vocabuilder"
minSdk 21
targetSdk 31
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
packagingOptions {
exclude 'META-INF/atomicfu.kotlin_module'
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation "androidx.appcompat:appcompat:$rootProject.appCompatVersion"
implementation "androidx.activity:activity-ktx:$rootProject.activityVersion"
// Dependencies for working with Architecture components
// You'll probably have to update the version numbers in build.gradle (Project)
// Room components
implementation "androidx.room:room-ktx:$rootProject.roomVersion"
kapt "androidx.room:room-compiler:$rootProject.roomVersion"
androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"
// Lifecycle components
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$rootProject.lifecycleVersion"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$rootProject.lifecycleVersion"
implementation "androidx.lifecycle:lifecycle-common-java8:$rootProject.lifecycleVersion"
// Kotlin components
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
api "org.jetbrains.kotlinx:kotlinx-coroutines-core:$rootProject.coroutines"
api "org.jetbrains.kotlinx:kotlinx-coroutines-android:$rootProject.coroutines"
// UI
implementation "androidx.constraintlayout:constraintlayout:$rootProject.constraintLayoutVersion"
implementation "com.google.android.material:material:$rootProject.materialVersion"
// Testing
testImplementation "junit:junit:$rootProject.junitVersion"
androidTestImplementation "androidx.arch.core:core-testing:$rootProject.coreTestingVersion"
androidTestImplementation ("androidx.test.espresso:espresso-core:$rootProject.espressoVersion", {
exclude group: 'com.android.support', module: 'support-annotations'
})
androidTestImplementation "androidx.test.ext:junit:$rootProject.androidxJunitVersion"
}

If you using kotlin version (1.7.0) shoud work with room latest alpha version (2.5.0-alpha02)
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.0"
implementation "androidx.room:room-runtime:2.5.0-alpha02"
implementation "androidx.room:room-ktx:2.5.0-alpha02"
kapt "androidx.room:room-compiler:2.5.0-alpha02"
If you want using room in stable version (2.4.2) should work with kotlin version (1.6.20)
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.20"
implementation "androidx.room:room-runtime:2.4.2"
implementation "androidx.room:room-ktx:2.4.2"
kapt "androidx.room:room-compiler:2.4.2"
I have tried both and they work. this is the reference: issue tracker

Update the Room version to 2.4.0-rc01.
In my case it solved the problem, and it works with Kotlin 1.6.0.

For me, kotlin-gradle-plugin 1.6.0 didn't work:
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.6.0"
but 1.5.31 worked:
classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.31'
Kotlin 1.6.0 with Room 2.4.0-rc01 worked too.
Thanks Stefano.

Room Persistance Library: Cannot find implementation for ContactAppDatabase (ContactAppDatabase_Impl does not exist)

I am implementing Room database for storing contacts for the jetpack compose project on Android Studio Bumblebee 2021.1.1 Canary 10. But I am getting an error as shown below
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.tana.contactapp, PID: 8843
java.lang.RuntimeException: cannot find implementation for com.tana.contactapp.data.ContactAppDatabase. ContactAppDatabase_Impl does not exist
Here is my app-level Gradle file
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
}
android {
compileSdk 30
defaultConfig {
applicationId "com.tana.contactapp"
minSdk 22
targetSdk 30
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
vectorDrawables {
useSupportLibrary true
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
buildFeatures {
compose true
}
composeOptions {
kotlinCompilerExtensionVersion compose_version
}
packagingOptions {
resources {
excludes += '/META-INF/{AL2.0,LGPL2.1}'
}
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.6.0'
implementation "androidx.compose.ui:ui:$compose_version"
implementation "androidx.compose.material:material:$compose_version"
implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
implementation "androidx.compose.material:material-icons-core:$compose_version"
implementation "androidx.compose.material:material-icons-extended:$compose_version"
implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.1'
implementation 'androidx.activity:activity-compose:1.3.0'
implementation 'androidx.room:room-ktx:2.3.0'
implementation 'androidx.compose.runtime:runtime-livedata:1.0.2'
implementation 'androidx.navigation:navigation-compose:2.4.0-alpha06'
annotationProcessor 'androidx.room:room-compiler:2.3.0'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
}
Here is the project-level Gradle file
task clean(type: Delete) {
delete rootProject.buildDir
}
buildscript {
ext {
compose_version = '1.0.2'
}
}
Here is settings.gradle file
pluginManagement {
repositories {
gradlePluginPortal()
google()
mavenCentral()
}
plugins {
id 'com.android.application' version '7.1.0-alpha10'
id 'com.android.library' version '7.1.0-alpha10'
id 'org.jetbrains.kotlin.android' version '1.5.21'
}
}
dependencyResolutionManagement {
repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
repositories {
google()
mavenCentral()
}
}
rootProject.name = "ContactApp"
include ':app'
Here is my Entity File
package com.tana.contactapp.data
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Person
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.room.Entity
import androidx.room.Ignore
import androidx.room.PrimaryKey
#Entity(tableName = "contacts")
data class Contact(
#PrimaryKey(autoGenerate = true) val id: Long = 0,
val name: String,
val number: String,
#Ignore val imageDp: ImageVector = Icons.Default.Person
)
Here is my DAO File
package com.tana.contactapp.data
import androidx.lifecycle.LiveData
import androidx.room.*
#Dao
interface ContactAppDao {
#Query("SELECT * FROM contacts")
fun getContacts(): LiveData<List<Contact>>
#Insert
suspend fun addContact(contact: Contact)
#Update
suspend fun updateContact(contact: Contact)
#Delete
suspend fun deleteContact(contact: Contact)
#Query("DELETE FROM contacts")
suspend fun deleteContacts()
}
Here is my Database File
package com.tana.contactapp.data
import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
#Database(entities = [Contact::class], version = 1, exportSchema = false)
abstract class ContactAppDatabase : RoomDatabase() {
abstract fun contactsDao(): ContactAppDao
companion object {
private var INSTANCE: ContactAppDatabase? = null
fun getDatabase(context: Context): ContactAppDatabase {
synchronized(this) {
var instance = INSTANCE
if (instance == null) {
instance = Room.databaseBuilder(
context.applicationContext,
ContactAppDatabase::class.java,
"contact_app_database"
).build()
}
return instance
}
}
}
}
I have tried a lot of solutions from the previous questions similar to this but none seems to work for my case

You need to remove
annotationProcessor 'androidx.room:room-compiler:2.3.0'
and add room compiler using kapt
kapt androidx.room:room-compiler:$room_version
https://developer.android.com/jetpack/androidx/releases/room#kts
and kapt plugin, on top of your root gradle file
apply plugin: "kotlin-kapt"

I solved this by adding id 'org.jetbrains.kotlin.kapt' version '1.5.21' in settings.gradle file plugins section, and then adding id 'org.jetbrains.kotlin.kapt' in app gradle file instead of 'kotlin-kapt'