Cristi提出的问题 -coding

Cristi

Asked: 2025-04-27 23:27:46 +0800 CST

使用 Hilt 时如何修复“无法创建 ViewModel 类的实例”？

我正在参加 JetPack Compose 课程，并尝试运行一个示例项目，展示 ViewModel 与 Hilt 的结合使用。

@AndroidEntryPoint
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

        setContent {
            Surface(color = MaterialTheme.colorScheme.background) {
                val noteViewModel: NoteViewModel = hiltViewModel<NoteViewModel>()
                // NoteApp(noteViewModel)
            }
        }
    }
}

为了初始化 ViewModel 我也尝试过

 noteViewModel by viewModels()

和

 noteViewModel = hiltViewModel()

ViewModel代码如下：

@HiltViewModel
class NoteViewModel @Inject constructor(private val repository: NoteRepository) : ViewModel() {
    //private var noteList = mutableStateListOf<Note>()

    private val _noteList = MutableStateFlow<List<Note>>(emptyList())
    val noteList = _noteList.asStateFlow()

    init {
        //noteList.addAll(NotesDataSource.loadDataNotes())
        viewModelScope.launch(Dispatchers.IO) {
            repository.getAllNotes().distinctUntilChanged().collect { listOfNotes ->
                if (listOfNotes.isEmpty()) {
                    Log.d("JetNote", "EmptyList")
                } else {
                    _noteList.value = listOfNotes
                }
            }
        }
    }

    fun addNote(note: Note) = viewModelScope.launch {
        repository.addNote(note)
    }

    fun updateNote(note: Note) = viewModelScope.launch {
        repository.updateNote(note)
    }

    fun removeNote(note: Note) = viewModelScope.launch {
        repository.deleteNote(note)
    }
}

Hilt 的 AppModule 设置如下：

@InstallIn(SingletonComponent::class)
@Module
object AppModule {

    @Singleton
    @Provides
    fun provideNotesDao(noteDatabase: NoteDatabase) : NoteDatabaseDao = noteDatabase.noteDao()

    @Singleton
    @Provides
    fun provideAppDatabase(@ApplicationContext context: Context) : NoteDatabase =
        Room.databaseBuilder(
            context,
            NoteDatabase::class.java,
            "notes_db"
        ).fallbackToDestructiveMigration().build()
}

注释存储库的代码：

class NoteRepository @Inject constructor(private val noteDatabaseDao: NoteDatabaseDao) {
    suspend fun addNote(note: Note) = noteDatabaseDao.insert(note)
    suspend fun updateNote(note: Note) = noteDatabaseDao.update(note)
    suspend fun deleteNote(note: Note) = noteDatabaseDao.deleteNote(note)
    suspend fun deleteAllNotes() = noteDatabaseDao.deleteAll()
    fun getAllNotes(): Flow<List<Note>> = noteDatabaseDao.getNotes().flowOn(Dispatchers.IO).conflate()
}

运行该应用程序时我收到的错误是：

java.lang.RuntimeException: Cannot create an instance of class com.course.jetnote.screens.NoteViewModel
........................
Caused by: java.lang.NoSuchMethodException: com.course.jetnote.screens.NoteViewModel.<init> []

这是我的 Gradle 设置：

构建.gradle.kts：

plugins {
    alias(libs.plugins.android.application)
    alias(libs.plugins.kotlin.android)
    alias(libs.plugins.kotlin.compose)
}

android {
    namespace = "com.course.jetnote"
    compileSdk = 35

    defaultConfig {
        applicationId = "com.course.jetnote"
        minSdk = 26
        targetSdk = 35
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_11
        targetCompatibility = JavaVersion.VERSION_11
    }
    kotlinOptions {
        jvmTarget = "11"
    }
    buildFeatures {
        compose = true
    }

    packaging {
        resources {
            excludes += "/META-INF/gradle/incremental.annotation.processors"
            excludes += "META-INF/androidx/room/room-compiler-processing/LICENSE.txt"
        }
    }

}

configurations.implementation {
    exclude(group = "org.jetbrains", module = "annotations")
}


dependencies {

    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.lifecycle.runtime.ktx)
    implementation(libs.androidx.activity.compose)
    implementation(platform(libs.androidx.compose.bom))
    implementation(libs.androidx.ui)
    implementation(libs.androidx.ui.graphics)
    implementation(libs.androidx.ui.tooling.preview)
    implementation(libs.androidx.material3)
    implementation(libs.androidx.lifecycle.viewModelCompose)
    implementation(libs.hilt.android)
    implementation(libs.hilt.compiler)
    implementation(libs.androidx.hilt.navigation.compose)
    implementation(libs.room.ktx)
    implementation(libs.room.runtime)
    implementation(libs.room.compiler)
    implementation(libs.kotlinx.coroutines.android)
    implementation(libs.androidx.room.runtime.android)

    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)
    androidTestImplementation(platform(libs.androidx.compose.bom))
    androidTestImplementation(libs.androidx.ui.test.junit4)
    debugImplementation(libs.androidx.ui.tooling)
    debugImplementation(libs.androidx.ui.test.manifest)
}

lib.versions.toml：

[versions]
agp = "8.8.2"
kotlin = "2.0.0"
coreKtx = "1.15.0"
junit = "4.13.2"
junitVersion = "1.2.1"
espressoCore = "3.6.1"
lifecycleRuntimeKtx = "2.8.7"
activityCompose = "1.10.1"
composeBom = "2024.04.01"
androidxLifecycle = "2.8.7"

androidxHiltNavigationCompose = "1.0.0"
hilt = "2.56.2"
hiltExt = "1.0.0"

room = "2.6.0"

kotlinxCoroutines = "1.10.0"
kotlinxDatetime = "0.6.0"
kotlinxSerializationJson = "1.8.0"
roomRuntimeAndroid = "2.7.1"

[libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
 junit = { group = "junit", name = "junit", version.ref = "junit" }
 androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
 androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
 androidx-ui = { group = "androidx.compose.ui", name = "ui" }
 androidx-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }
 androidx-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
 androidx-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
 androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
 androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
 androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
 androidx-lifecycle-viewModelCompose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "androidxLifecycle" }


hilt-android = { group = "com.google.dagger", name = "hilt-android", version.ref = "hilt" }
hilt-compiler = { group = "com.google.dagger", name = "hilt-android-compiler", version.ref = "hilt" }
hilt-ext-compiler = { group = "androidx.hilt", name = "hilt-compiler", version.ref = "hiltExt" }
androidx-hilt-navigation-compose = { group = "androidx.hilt", name = "hilt-navigation-compose", version.ref = "androidxHiltNavigationCompose" }



#Database
room-runtime = { group = "androidx.room", name = "room-runtime", version.ref = "room" }
room-ktx = { group = "androidx.room", name = "room-ktx", version.ref = "room" }
room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }

#Kotlin Coroutines, serialization, datetime...
kotlinx-coroutines-android = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-android", version.ref = "kotlinxCoroutines" }
kotlinx-datetime = { group = "org.jetbrains.kotlinx", name = "kotlinx-datetime", version.ref = "kotlinxDatetime" }
kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
androidx-room-runtime-android = { group = "androidx.room", name = "room-runtime-android", version.ref = "roomRuntimeAndroid" }

[plugins]
android-application = { id = "com.android.application", version.ref = "agp" }
kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }

Cristi

Asked: 2023-12-29 01:38:35 +0800 CST

SecurityFilterChain 方法 Spring Boot 3.1.5 Kotlin

我正在尝试使用 Spring Boot 3.1.5 创建 securityFilterChain 方法

这是我所拥有的：

@Bean
@Throws(java.lang.Exception::class)
fun securityFilterChain(http: HttpSecurity): SecurityFilterChain? {
    http
        .authorizeHttpRequests(
            Customizer<AuthorizationManagerRequestMatcherRegistry> { authorizeHttpRequests: AuthorizationManagerRequestMatcherRegistry ->
                authorizeHttpRequests
                    .requestMatchers("/**").hasRole("USER")
            }
        )
    return http.build()
}

不幸的是，我收到此编译错误：“应为外部类指定类型参数。使用完整的类名来指定它们。”

任何人都可以指导正确的方向吗？

这是我尝试过的其他方法：

@Bean
@Throws(Exception::class)
     fun filterChain(http: HttpSecurity): SecurityFilterChain {
         http.authorizeHttpRequests((requests) -> requests
        .requestMatchers("/users/registration").permitAll())
        return http.build()
     }

但这也不能编译。

以下是项目依赖项：

dependencies {
    implementation("org.apache.tomcat.embed:tomcat-embed-jasper")
    implementation("org.springframework.boot:spring-boot-starter-data-jpa")
    implementation("org.springframework.boot:spring-boot-starter-validation")
    implementation("org.springframework.boot:spring-boot-starter-security")
    implementation("org.springframework.boot:spring-boot-starter-web")
    implementation("org.springframework.security:spring-security-core")
    implementation("org.springframework.security:spring-security-config")
    implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
    implementation("org.jetbrains.kotlin:kotlin-reflect")
    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    implementation("io.jsonwebtoken:jjwt:0.9.0")
    implementation("org.postgresql:postgresql")
    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core")
    testImplementation("org.springframework.boot:spring-boot-starter-test") {
         exclude(group = "org.junit.vintage", module = "junit-vintage-engine")
    }
    testImplementation("org.springframework.security:spring-security-test")
}

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