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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
}

'dagger.hilt.android.internal.lifecycle.DefaultActivityViewModelFactory' could not be resolved

I have spent the hole week trying to add hilt dependency injection to my sample note application, android studio have been throwing on me error after an error.It got me mad, any way, in AppModule i have been trying to inject my room database to app repository and then my app repo to my use cases class and at the end injecting use cases class to my sharedViewModel
so this is my AppModule object:
#Module
#InstallIn(SingletonComponent::class)
object AppModule {
#Provides
#Singleton
fun provideNoteDatabase(app: Application): NoteDatabase {
return Room.databaseBuilder(
app,
NoteDatabase::class.java,
NoteDatabase.DATABASE_NAME
).build()
}
#Provides
#Singleton
fun provideNoteRepository(db: NoteDatabase): NotesRepo {
return RepoImplementation(db.noteDao())
}
#Provides
#Singleton
fun provideNoteUseCase(repo: NotesRepo): NoteUseCase {
return NoteUseCase(
getNotesUseCase = GetNotesUseCase(repo),
deleteNoteUseCase = DeleteNoteUseCase(repo),
updateNoteUseCase = UpdateNoteUseCase(repo),
insertNoteUseCase = InsertNoteUseCase(repo)
)
}
}
and this my Application class:
#HiltAndroidApp
class Application : Application()
my edit fragment:
#AndroidEntryPoint
class EditFragment : Fragment() {
private var _binding: FragmentEditBinding? = null
private val binding get() = _binding!!
private val viewModel: SharedViewModel by activityViewModels()
//...
}
my other fragment:
#AndroidEntryPoint
class MainFragment : Fragment() {
private var _binding: FragmentMainBinding? = null
private val binding get() = _binding!!
private val viewModel: SharedViewModel by activityViewModels()
//...
}
by the way also my MainActivity is annotated with #AndroidEntryPoint
my famous viewModel :
#HiltViewModel
class SharedViewModel #Inject constructor(private val noteUseCase: NoteUseCase) :
ViewModel() {...}
this is project level build.gradle:
buildscript {
repositories {
google()
mavenCentral()
}
dependencies {
def nav_version = "2.5.2"
classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$nav_version"
classpath 'com.google.dagger:hilt-android-gradle-plugin:2.44'
}
}
plugins {
id 'com.android.application' version '7.3.0' apply false
id 'com.android.library' version '7.3.0' apply false
id 'org.jetbrains.kotlin.android' version '1.7.10' apply false
}
and module level build.gradle:
plugins {
id 'com.android.application'
id 'org.jetbrains.kotlin.android'
id 'kotlin-android'
id 'kotlin-kapt'
id "androidx.navigation.safeargs"
id 'com.google.dagger.hilt.android'
}
android {
compileSdk 32
defaultConfig {
applicationId "com.example.stayin"
minSdk 21
targetSdk 32
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
kotlinOptions {
jvmTarget = '1.8'
}
buildFeatures {
dataBinding true
viewBinding true
}
namespace 'com.example.stayin'
}
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.4.2'
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
def lifecycle_version = "2.4.1"
implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
// coroutines for getting off the UI thread
def coroutines = "1.6.0"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines"
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines"
//shared preferences dependency
implementation 'androidx.preference:preference-ktx:1.2.0'
// Room dependency
def room_version = "2.4.3"
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"
// Kotlin Extensions and Coroutines support for Room
implementation "androidx.room:room-ktx:$room_version"
//navigation component dependency
implementation "androidx.navigation:navigation-fragment-ktx:2.5.2"
implementation "androidx.navigation:navigation-ui-ktx:2.5.2"
//Dagger - Hilt
implementation 'com.google.dagger:hilt-android:2.44'
kapt 'com.google.dagger:hilt-compiler:2.44'
// For instrumentation tests
androidTestImplementation 'com.google.dagger:hilt-android-testing:2.44'
kaptAndroidTest 'com.google.dagger:hilt-compiler:2.44'
// For local unit tests
testImplementation 'com.google.dagger:hilt-android-testing:2.44'
kaptTest 'com.google.dagger:hilt-compiler:2.44'
implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03"
}
if can any one help me to find what is wrong and explained why, i will be so thankful towards him. i rally need to pass this so i can level up in my career.

Remove below deprecated dependency:
implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03"
(It was deprecated since dagger-2.34 version)
proof:
https://github.com/google/dagger/releases/tag/dagger-2.34
Also Try to upgrade your lifecycle version as below:
def lifecycle_version = "2.5.1"
add below lines after dependency section in build.gradle(app):
kapt { correctErrorTypes true }
follow official documentation:
https://developer.android.com/training/dependency-injection/hilt-android
https://dagger.dev/hilt/view-model.html

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

MyRoomDatabase_Impl does not exist

I am facing some issue using Room DB
java.lang.RuntimeException: cannot find implementation for
com.zeliot.roomtuto.db.NoteDB. NoteDB_Impl does not exist
below is my app grale
plugins {
id 'com.android.application'
id 'kotlin-android'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.zeliot.roomtuto"
minSdk 23
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
}
kotlinOptions {
jvmTarget = '1.8'
}
}
dependencies {
implementation 'androidx.core:core-ktx:1.6.0'
implementation 'androidx.appcompat:appcompat:1.3.1'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.0'
testImplementation 'junit:junit:4.+'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
//Room
def room_version = "2.3.0"
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
implementation "androidx.room:room-ktx:$room_version"
// Coroutine Lifecycle Scopes
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1"
implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.3.1"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.1"
//coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0'
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0'
}
#Entity(
tableName = "note"
)
data class Note(
#PrimaryKey(autoGenerate = true)
var id:Int?=null,
val title :String,
val desciption:String,
val datetime:String,
)
#Dao
interface NoteDao {
#Insert
fun insert(note: Note)
#Delete
fun delete(note: Note)
#Query("select * from note")
fun getNotes(): LiveData<List<Note>>
#Update
fun update(note: Note)
}
#Database(
entities = [Note::class],
version = 1
)
abstract class NoteDB :RoomDatabase() {
abstract fun getNoteDao():NoteDao
companion object{
#Volatile
private var instance : NoteDB? = null
fun createDB(context: Context) :NoteDB{
return instance ?:
Room.databaseBuilder(
context.applicationContext,
NoteDB::class.java,
"Note_db.db"
)
.build()
}
}
}
UNABLE TO GET THE ANSWER ,I HAVE TRIED MANY SOLUTIONS BUT DIDN'T WORK.
I have tried many solution which are already available in stackoverflow but those solutions didnt work.

In Apple M1 chip we need to use room version of 2.4.0-alpha04.
plugins {
id 'com.android.application'
id 'kotlin-android'
id'kotlin-kapt'
}
implementation "androidx.room:room-runtime:2.4.0-alpha04"
implementation "androidx.room:room-ktx:2.4.0-alpha04"
kapt "androidx.room:room-compiler:2.4.0-alpha04"
issue tracker link https://issuetracker.google.com/issues/174695268?pli=1#comment13

Change :-
plugins {
id 'com.android.application'
id 'kotlin-android'
}
to
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
}
and then change
annotationProcessor "androidx.room:room-compiler:$room_version"
to
kapt "androidx.room:room-compiler:$room_version"

How to get LiveData from Room?

I'm trying to get LiveData from Room. So my RecycleView can have Live updates if anything in database is changed
I have tried with out LiveData and that works, but when i add LiveData that always shows this error.
error: Not sure how to convert a Cursor to this method's return type (androidx.lifecycle.LiveData<java.util.List<com.example.models.Club>>).
public abstract java.lang.Object getAll(#org.jetbrains.annotations.NotNull()
I googled and looked on this site for solution, but every on with this issue have used rxjava, rxandroid, rxkotlin or ArrayList.
And for them solution is to replace ArrayList with List, and for RX to try coroutine.
Well i am using Coroutine and List and still no progress.
This is my ClubDao
ClubDao
#Query("SELECT * FROM club")
suspend fun getAll(): LiveData<List<Club>>
In Club i have this attributes
Club
#Entity
data class Club(#PrimaryKey var id: Int,
#ColumnInfo(name = "logo_url") var logoUrl: String,
#ColumnInfo(name = "name") var name: String,
#ColumnInfo(name = "town") var town: String,
#ColumnInfo(name = "address") var address: String,
#ColumnInfo(name = "contact_name") var contactName: String,
#ColumnInfo(name = "phone_numbers") var phoneNumbers: String,
#ColumnInfo(name = "email") var email: String)
phoneNumbers should be List, but i convert those to and from json with TypeConverters
TypeConverter is here
TypeConverter
class ConvertersDB {
#TypeConverter
fun fromString(value: String): ArrayList<String> {
val listType = object : TypeToken<ArrayList<String>>() {
}.type
return Gson().fromJson(value, listType)
}
#TypeConverter
fun fromArrayList(list: ArrayList<String>): String {
val gson = Gson()
return gson.toJson(list)
}
}
And my DB
DataBase
#Database(entities = [Club::class], version = 1, exportSchema = false)
#TypeConverters(ConvertersDB::class)
abstract class AppDatabase : RoomDatabase() {
abstract fun clubDao(): ClubDao
companion object {
#Volatile
private var instance: AppDatabase? = null
private val LOCK = Any()
operator fun invoke(context: Context) = instance ?: synchronized(LOCK) {
instance ?: buildDatabase(context).also { instance = it }
}
private fun buildDatabase(context: Context) = Room.databaseBuilder(context,
AppDatabase::class.java, "pss.db")
.allowMainThreadQueries()
.build()
}
}
In my fragment i need to observe all the clubs from database via ViewModel and Repository and send them to RecycleView
Now i am getting error:
error: Not sure how to convert a Cursor to this method's return type (androidx.lifecycle.LiveData<java.util.List<com.example.models.Club>>).
public abstract java.lang.Object getAll(#org.jetbrains.annotations.NotNull()
Does anyone know solution for this?
EDIT:
Gradle
apply plugin: 'com.android.application'
apply plugin: 'androidx.navigation.safeargs'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.overswayit.plesnisavezsrbije"
minSdkVersion 24
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
dataBinding {
enabled true
}
packagingOptions {
exclude 'META-INF/atomicfu.kotlin_module'
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.31"
implementation 'com.jakewharton:butterknife:10.1.0'
implementation 'com.google.android.material:material:1.1.0-alpha07'
implementation 'androidx.cardview:cardview:1.0.0'
implementation 'androidx.appcompat:appcompat:1.1.0-beta01'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
// Room components
implementation "androidx.room:room-runtime:$rootProject.roomVersion"
implementation "androidx.room:room-ktx:$rootProject.roomVersion"
kapt "androidx.room:room-compiler:$rootProject.roomVersion"
androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"
// Room and RxJava
implementation "androidx.room:room-rxjava2:$rootProject.roomVersion"
// Lifecycle components
implementation "androidx.lifecycle:lifecycle-extensions:$rootProject.archLifecycleVersion"
kapt "androidx.lifecycle:lifecycle-compiler:$rootProject.archLifecycleVersion"
androidTestImplementation "androidx.arch.core:core-testing:$rootProject.androidxArchVersion"
// ViewModel Kotlin support
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$rootProject.archLifecycleVersion"
//LiveData Kotlin
implementation "androidx.lifecycle:lifecycle-livedata:$rootProject.archLifecycleVersion"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$rootProject.archLifecycleVersion"
implementation "androidx.lifecycle:lifecycle-runtime-ktx:$rootProject.archLifecycleVersion"
// Coroutines
api "org.jetbrains.kotlinx:kotlinx-coroutines-core:$rootProject.coroutines"
api "org.jetbrains.kotlinx:kotlinx-coroutines-android:$rootProject.coroutines"
//RxJava
implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
implementation "io.reactivex.rxjava2:rxjava:2.2.6"
implementation 'com.jakewharton.rxbinding3:rxbinding:3.0.0-alpha2'
implementation "org.jetbrains.kotlin:kotlin-stdlib:1.3.31"
annotationProcessor 'com.jakewharton:butterknife-compiler:10.1.0'
implementation 'com.squareup.picasso:picasso:2.71828'
implementation 'com.kaopiz:kprogresshud:1.0.5'
implementation 'com.squareup:otto:1.3.8'
implementation 'agency.tango.android:avatar-view:0.0.2'
implementation 'agency.tango.android:avatar-view-picasso:0.0.2'
implementation 'com.mikhaellopez:circularimageview:3.2.0'
implementation 'com.googlecode.libphonenumber:libphonenumber:8.1.0'
// Data Binding
kapt "com.android.databinding:compiler:3.1.4"
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.2.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
implementation project(path: ':tuple')
// Navigation Component
implementation 'androidx.navigation:navigation-fragment-ktx:2.0.0'
implementation 'androidx.navigation:navigation-ui-ktx:2.0.0'
//Gson
implementation 'com.google.code.gson:gson:2.8.5'
}
kapt {
generateStubs = true
}
Top Level Gradle
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.4.1'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.31"
classpath "android.arch.navigation:navigation-safe-args-gradle-plugin:1.0.0"
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
ext {
roomVersion = '2.1.0'
archLifecycleVersion = '2.2.0-alpha01'
androidxArchVersion = '2.0.0'
coroutines = '1.2.0'
}

As mentioned in the comments, remove suspend.
When a method returns an observable, there is no reason to make it suspend since it just returns and object, does not run any query until it is observed.
#Query("SELECT * FROM club")
fun getAll(): LiveData<List<Club>>
Room's coroutines integration brings ability to return suspend values but when the value itself is asnyc, there is no reason to use it.

I found a good solution to the problem with using rxJava with room and livedata.
The approach is similar to using Retrofit with RxJava, using LiveDataReactiveStreams, which
by default uses flowable.
In your approach i would recomend is:
#Query("SELECT * FROM club")
suspend fun getAll(): LiveData<List<Club>>
changed to
DAO:
#Query("SELECT * FROM club")
fun getAll(): (Any rxJava object) Flowable<List<Club>>
Repository:
fun getAllClubs() : LiveData<List<Club>>{
return LiveDataReactiveStreams.fromPublisher(dao.getAll()"do any transformation or
other functionality you want and then if using Maybe for example transform to
flowable by .toFlowable()")
}
ViewModel:
val clubList : MediatorLiveData<List<Club>>()
fun setClubData(){
clubList.addSource(repository.getAllClubs(), {
clubList.value = it
})
}
then you can observe the livedata object as usual in your view.
Hope what i wrote is understandable, if not i will try to make it better :)