找不到实现（房间）
cannot find implementation ( Room )
我对 Room 或 idk 有问题，实际上问题出在哪里，我需要帮助找出问题出在哪里，我正在使用 Hilt DI，那一刻创建数据库实例时它崩溃了这是我的代码
错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.todo, PID: 1895
java.lang.RuntimeException: cannot find implementation for com.example.todo.data.ToDoDatabase. ToDoDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:97)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1358)
at com.example.todo.di.AppModule.provideToDoDatabase(AppModule.kt:27)
at com.example.todo.di.AppModule_ProvideToDoDatabaseFactory.provideToDoDatabase(AppModule_ProvideToDoDatabaseFactory.java:33)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.toDoDatabase(DaggerMainApplication_HiltComponents_SingletonC.java:69)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.access00(DaggerMainApplication_HiltComponents_SingletonC.java:48)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:583)
at dagger.internal.DoubleCheck.get(DoubleCheck.java:47)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.toDoDao(DaggerMainApplication_HiltComponents_SingletonC.java:73)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.access00(DaggerMainApplication_HiltComponents_SingletonC.java:48)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:580)
at dagger.internal.DoubleCheck.get(DoubleCheck.java:47)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.toDoRepository(DaggerMainApplication_HiltComponents_SingletonC.java:448)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.toDoViewModel(DaggerMainApplication_HiltComponents_SingletonC.java:452)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.access00(DaggerMainApplication_HiltComponents_SingletonC.java:429)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:487)
at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:100)
at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:69)
at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:84)
at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:109)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:171)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:139)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:44)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:31)
at com.example.todo.fragments.add.AddFragment.getViewModel(AddFragment.kt:20)
at com.example.todo.fragments.add.AddFragment.insertDataToDo(AddFragment.kt:63)
at com.example.todo.fragments.add.AddFragment.onOptionsItemSelected(AddFragment.kt:45)
at androidx.fragment.app.Fragment.performOptionsItemSelected(Fragment.java:3122)
at androidx.fragment.app.FragmentManager.dispatchOptionsItemSelected(FragmentManager.java:3226)
at androidx.fragment.app.Fragment.performOptionsItemSelected(Fragment.java:3126)
at androidx.fragment.app.FragmentManager.dispatchOptionsItemSelected(FragmentManager.java:3226)
at androidx.fragment.app.FragmentController.dispatchOptionsItemSelected(FragmentController.java:416)
at androidx.fragment.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:358)
at androidx.appcompat.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:264)
at androidx.appcompat.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:109)
at androidx.appcompat.app.AppCompatDelegateImpl.onMenuItemSelected(AppCompatDelegateImpl.java:1179)
at androidx.appcompat.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:834)
at androidx.appcompat.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:158)
at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:985)
at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:975)
at androidx.appcompat.widget.ActionMenuView.invokeItem(ActionMenuView.java:624)
at androidx.appcompat.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:151)
at android.view.View.performClick(View.java:7441)
at android.view.View.performClickInternal(View.java:7418)
at android.view.View.access00(View.java:835)
at android.view.View$PerformClick.run(View.java:28676)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7842)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
build.gradle
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
id 'androidx.navigation.safeargs.kotlin'
id 'dagger.hilt.android.plugin'
id 'kotlin-parcelize'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.example.todo"
minSdk 24
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'
}
buildFeatures {
dataBinding true
viewBinding true
}
}
dependencies {
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
def nav_version = "2.3.5"
def room_version = "2.3.0"
def lifecycle_version = "2.4.0"
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.3.1'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
testImplementation 'junit:junit:'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
//Navigation component
implementation "androidx.navigation:navigation-fragment-ktx:$nav_version"
implementation "androidx.navigation:navigation-ui-ktx:$nav_version"
//Room
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
// Lifecycle
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
//Kotlin coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0'
//RecyclerView
implementation 'jp.wasabeef:recyclerview-animators:4.0.2'
//Hilt DI
implementation "com.google.dagger:hilt-android:2.38.1"
kapt "com.google.dagger:hilt-compiler:2.38.1"
}
ToDoData.kt
@Entity(tableName = "todo_table")
@Parcelize
data class ToDoData(
@PrimaryKey(autoGenerate = true)
var id: Int,
var title: String,
var description: String,
var priority: Priority
) : Parcelable
ToDoDatabase.kt
@Database(entities = [ToDoData::class], version = 1, exportSchema = false)
@TypeConverters(Converter::class)
abstract class ToDoDatabase : RoomDatabase() {
abstract fun toDoDao(): ToDoDao
}
ToDoViewModel.kt
@HiltViewModel
class ToDoViewModel @Inject constructor(
private val repository: ToDoRepository
) : ViewModel() {
private val getAllData: LiveData<List<ToDoData>> = repository.getAllData
fun insertData(toDoData: ToDoData) {
viewModelScope.launch(Dispatchers.IO) {
repository.insertData(toDoData)
}
}
}
AppModule.kt
@Module
@InstallIn(SingletonComponent::class)
object AppModule {
@Singleton
@Provides
fun provideToDoDatabase(
@ApplicationContext app: Context
) = Room.databaseBuilder(
app,
ToDoDatabase::class.java,
"todo_database"
)
.fallbackToDestructiveMigration()
.build()
@Singleton
@Provides
fun provideTodoDao(db: ToDoDatabase) = db.toDoDao()
}
AddFragment.kt
这是我从 AddFragment
插入数据所调用的函数
private val viewModel: ToDoViewModel by viewModels()
private fun insertDataToDo() {
val title = binding.titleEt.text.toString()
val priority = binding.spinnerPriorities.selectedItem.toString()
val description = binding.descriptionEt.text.toString()
val validation = verifyDataFromUser(title, description)
if (validation) {
val data = ToDoData(
0,
title,
description,
parsePriority(priority)
)
viewModel.insertData(data)
Toast.makeText(requireContext(), "Successfully Added!", Toast.LENGTH_SHORT).show()
findNavController().navigate(R.id.action_addFragment_to_listFragment)
} else
Toast.makeText(requireContext(), "Please fill out all fields", Toast.LENGTH_SHORT)
.show()
}
private fun verifyDataFromUser(title: String, description: String): Boolean {
return if (TextUtils.isEmpty(title) || TextUtils.isEmpty(description)) {
false
} else !(title.isEmpty() || description.isEmpty())
}
private fun parsePriority(priority: String): Priority {
return when (priority) {
"High Priority" -> Priority.HIGH
"Medium Priority" -> Priority.MEDIUM
"Low Priority" -> Priority.LOW
else -> Priority.LOW
}
}
我已经在这里看到了一些相同问题的问题，但它对我不起作用，所以我知道问题出在哪里
我和你遇到了完全一样的问题，经过半天的尝试重写和删除代码片段，最终通过将 annotationProcessor 更改为 kapt 解决了我的问题在 build.gradle 文件中。
// Hilt, Dependency injection
def hilt_version = "2.38.1"
implementation "com.google.dagger:hilt-android:$hilt_version"
annotationProcessor "com.google.dagger:hilt-compiler:$hilt_version"
// Room database
def room_version = "2.4.2"
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
更改和修复后：
// Hilt, Dependency injection
def hilt_version = "2.38.1"
implementation "com.google.dagger:hilt-android:$hilt_version"
kapt "com.google.dagger:hilt-compiler:$hilt_version"
// Room database
def room_version = "2.4.2"
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"
鉴于控制台上打印的错误文本，我认为这根本不是问题！
我对 Room 或 idk 有问题，实际上问题出在哪里，我需要帮助找出问题出在哪里，我正在使用 Hilt DI，那一刻创建数据库实例时它崩溃了这是我的代码
错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.todo, PID: 1895
java.lang.RuntimeException: cannot find implementation for com.example.todo.data.ToDoDatabase. ToDoDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:97)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1358)
at com.example.todo.di.AppModule.provideToDoDatabase(AppModule.kt:27)
at com.example.todo.di.AppModule_ProvideToDoDatabaseFactory.provideToDoDatabase(AppModule_ProvideToDoDatabaseFactory.java:33)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.toDoDatabase(DaggerMainApplication_HiltComponents_SingletonC.java:69)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.access00(DaggerMainApplication_HiltComponents_SingletonC.java:48)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:583)
at dagger.internal.DoubleCheck.get(DoubleCheck.java:47)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.toDoDao(DaggerMainApplication_HiltComponents_SingletonC.java:73)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC.access00(DaggerMainApplication_HiltComponents_SingletonC.java:48)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:580)
at dagger.internal.DoubleCheck.get(DoubleCheck.java:47)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.toDoRepository(DaggerMainApplication_HiltComponents_SingletonC.java:448)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.toDoViewModel(DaggerMainApplication_HiltComponents_SingletonC.java:452)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl.access00(DaggerMainApplication_HiltComponents_SingletonC.java:429)
at com.example.todo.DaggerMainApplication_HiltComponents_SingletonC$ViewModelCImpl$SwitchingProvider.get(DaggerMainApplication_HiltComponents_SingletonC.java:487)
at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:100)
at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:69)
at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:84)
at dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:109)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:171)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:139)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:44)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelLazy.kt:31)
at com.example.todo.fragments.add.AddFragment.getViewModel(AddFragment.kt:20)
at com.example.todo.fragments.add.AddFragment.insertDataToDo(AddFragment.kt:63)
at com.example.todo.fragments.add.AddFragment.onOptionsItemSelected(AddFragment.kt:45)
at androidx.fragment.app.Fragment.performOptionsItemSelected(Fragment.java:3122)
at androidx.fragment.app.FragmentManager.dispatchOptionsItemSelected(FragmentManager.java:3226)
at androidx.fragment.app.Fragment.performOptionsItemSelected(Fragment.java:3126)
at androidx.fragment.app.FragmentManager.dispatchOptionsItemSelected(FragmentManager.java:3226)
at androidx.fragment.app.FragmentController.dispatchOptionsItemSelected(FragmentController.java:416)
at androidx.fragment.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:358)
at androidx.appcompat.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:264)
at androidx.appcompat.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:109)
at androidx.appcompat.app.AppCompatDelegateImpl.onMenuItemSelected(AppCompatDelegateImpl.java:1179)
at androidx.appcompat.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:834)
at androidx.appcompat.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:158)
at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:985)
at androidx.appcompat.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:975)
at androidx.appcompat.widget.ActionMenuView.invokeItem(ActionMenuView.java:624)
at androidx.appcompat.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:151)
at android.view.View.performClick(View.java:7441)
at android.view.View.performClickInternal(View.java:7418)
at android.view.View.access00(View.java:835)
at android.view.View$PerformClick.run(View.java:28676)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7842)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
build.gradle
plugins {
id 'com.android.application'
id 'kotlin-android'
id 'kotlin-kapt'
id 'androidx.navigation.safeargs.kotlin'
id 'dagger.hilt.android.plugin'
id 'kotlin-parcelize'
}
android {
compileSdk 31
defaultConfig {
applicationId "com.example.todo"
minSdk 24
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'
}
buildFeatures {
dataBinding true
viewBinding true
}
}
dependencies {
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
def nav_version = "2.3.5"
def room_version = "2.3.0"
def lifecycle_version = "2.4.0"
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.3.1'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
testImplementation 'junit:junit:'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
//Navigation component
implementation "androidx.navigation:navigation-fragment-ktx:$nav_version"
implementation "androidx.navigation:navigation-ui-ktx:$nav_version"
//Room
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
// Lifecycle
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
//Kotlin coroutines
implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0'
//RecyclerView
implementation 'jp.wasabeef:recyclerview-animators:4.0.2'
//Hilt DI
implementation "com.google.dagger:hilt-android:2.38.1"
kapt "com.google.dagger:hilt-compiler:2.38.1"
}
ToDoData.kt
@Entity(tableName = "todo_table")
@Parcelize
data class ToDoData(
@PrimaryKey(autoGenerate = true)
var id: Int,
var title: String,
var description: String,
var priority: Priority
) : Parcelable
ToDoDatabase.kt
@Database(entities = [ToDoData::class], version = 1, exportSchema = false)
@TypeConverters(Converter::class)
abstract class ToDoDatabase : RoomDatabase() {
abstract fun toDoDao(): ToDoDao
}
ToDoViewModel.kt
@HiltViewModel
class ToDoViewModel @Inject constructor(
private val repository: ToDoRepository
) : ViewModel() {
private val getAllData: LiveData<List<ToDoData>> = repository.getAllData
fun insertData(toDoData: ToDoData) {
viewModelScope.launch(Dispatchers.IO) {
repository.insertData(toDoData)
}
}
}
AppModule.kt
@Module
@InstallIn(SingletonComponent::class)
object AppModule {
@Singleton
@Provides
fun provideToDoDatabase(
@ApplicationContext app: Context
) = Room.databaseBuilder(
app,
ToDoDatabase::class.java,
"todo_database"
)
.fallbackToDestructiveMigration()
.build()
@Singleton
@Provides
fun provideTodoDao(db: ToDoDatabase) = db.toDoDao()
}
AddFragment.kt
这是我从 AddFragment
插入数据所调用的函数 private val viewModel: ToDoViewModel by viewModels()
private fun insertDataToDo() {
val title = binding.titleEt.text.toString()
val priority = binding.spinnerPriorities.selectedItem.toString()
val description = binding.descriptionEt.text.toString()
val validation = verifyDataFromUser(title, description)
if (validation) {
val data = ToDoData(
0,
title,
description,
parsePriority(priority)
)
viewModel.insertData(data)
Toast.makeText(requireContext(), "Successfully Added!", Toast.LENGTH_SHORT).show()
findNavController().navigate(R.id.action_addFragment_to_listFragment)
} else
Toast.makeText(requireContext(), "Please fill out all fields", Toast.LENGTH_SHORT)
.show()
}
private fun verifyDataFromUser(title: String, description: String): Boolean {
return if (TextUtils.isEmpty(title) || TextUtils.isEmpty(description)) {
false
} else !(title.isEmpty() || description.isEmpty())
}
private fun parsePriority(priority: String): Priority {
return when (priority) {
"High Priority" -> Priority.HIGH
"Medium Priority" -> Priority.MEDIUM
"Low Priority" -> Priority.LOW
else -> Priority.LOW
}
}
我已经在这里看到了一些相同问题的问题，但它对我不起作用，所以我知道问题出在哪里
我和你遇到了完全一样的问题，经过半天的尝试重写和删除代码片段，最终通过将 annotationProcessor 更改为 kapt 解决了我的问题在 build.gradle 文件中。
// Hilt, Dependency injection
def hilt_version = "2.38.1"
implementation "com.google.dagger:hilt-android:$hilt_version"
annotationProcessor "com.google.dagger:hilt-compiler:$hilt_version"
// Room database
def room_version = "2.4.2"
implementation "androidx.room:room-runtime:$room_version"
annotationProcessor "androidx.room:room-compiler:$room_version"
更改和修复后：
// Hilt, Dependency injection
def hilt_version = "2.38.1"
implementation "com.google.dagger:hilt-android:$hilt_version"
kapt "com.google.dagger:hilt-compiler:$hilt_version"
// Room database
def room_version = "2.4.2"
implementation "androidx.room:room-runtime:$room_version"
kapt "androidx.room:room-compiler:$room_version"
鉴于控制台上打印的错误文本，我认为这根本不是问题！