Room DataBase Implementation not found w/Jetpack Compose

Issue

I have looked around here and other sites, but I can't figure out the solution.

everything worked fine till I initialized the RoomViewModel.kt in MainActivity.kt.

I keep getting this error

    java.lang.RuntimeException: cannot find implementation for com.caller.fakecaller.data.DataBase. DataBase_Impl does not exist
        at androidx.room.Room.getGeneratedImplementation(Room.java:97)
        at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1358)
        at com.caller.fakecaller.data.DataBase$Companion.getInstance(DataBase.kt:31)
        at com.caller.fakecaller.data.RoomViewModel.<init>(RoomViewModel.kt:18)
        at com.caller.fakecaller.util.RoomViewModelFactory.create(RoomViewModelFactory.kt:14)...

I have this gradle

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
}

android {
    compileSdk 31

    defaultConfig {
        applicationId "com.caller.fakecaller"
        minSdk 21
        targetSdk 31
        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 '1.0.2'
    }
    packagingOptions {
        resources {
            excludes += '/META-INF/{AL2.0,LGPL2.1}'
        }
    }
}

dependencies {

    implementation 'androidx.core:core-ktx:1.6.0'
    implementation "androidx.compose.ui:ui:1.0.2"
    implementation "androidx.compose.material:material:1.0.2"
    implementation "androidx.compose.ui:ui-tooling-preview:1.0.2"
    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.1'
    implementation 'androidx.activity:activity-compose:1.3.1'
    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-junit4:1.0.2"
    debugImplementation "androidx.compose.ui:ui-tooling:1.0.2"

    //Room
    implementation "androidx.room:room-runtime:2.3.0"
    annotationProcessor "androidx.room:room-compiler:2.3.0"
    // optional - Kotlin Extensions and Coroutines support for Room
    implementation("androidx.room:room-ktx:2.3.0")

    // Lifecycle components
    implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.3.1"
    implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
    implementation "androidx.lifecycle:lifecycle-common-java8:2.3.1"
    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1"

    //Navigation with Compose
    implementation("androidx.navigation:navigation-compose:2.4.0-alpha08")

    //Preferences
    implementation("androidx.preference:preference-ktx:1.1.1")

    //Activity
    implementation 'androidx.activity:activity-ktx:1.4.0-alpha01'

    //Glide Accompanist
    implementation "dev.chrisbanes.accompanist:accompanist-glide:0.4.2"

}

when i added the plugins kotlin-android and kotlin-kapt it said that they weren't found. therefore i had to change the app gradle to be like this (based on other posts)

// Top-level build file where you can add configuration options common to all sub-projects/modules.
task clean(type: Delete) {
    delete rootProject.buildDir
}
buildscript {

    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.30"
    }
}

allprojects {
    configurations.all {
        resolutionStrategy {
            cacheChangingModulesFor 0, 'seconds'
        }
    }
}

but that gave me these errors

com/android/build/gradle/BaseExtension
> com.android.build.gradle.BaseExtension


Unable to load class 'com.android.build.gradle.BaseExtension'.

in the database file I did as follows:

private const val DATABASE_NAME = "FakeCaller"


@Database(entities = [Contact::class, RingTone::class], version = 1, exportSchema = false)
abstract class DataBase:RoomDatabase() {

    abstract fun UserDao(): UserDao

    abstract fun RingDao():RingDao

//Implementing the DataBase
    companion object {
        @Volatile
        private var INSTANCE: DataBase? = null

        fun getInstance(context: Context): DataBase {
            synchronized(this) {
                var instance = INSTANCE

                if (instance == null) {
                    instance = Room.databaseBuilder(
                        context.applicationContext,
                        DataBase::class.java,
                        DATABASE_NAME
                    ).build()

                    INSTANCE = instance
                }
                return instance
            }
        }
    }
}

and connected everything to the RoomViewModel (I created a factory for it also)

class RoomViewModel(application: Application) : AndroidViewModel(application) {

    val readContactList : LiveData<List<Contact>>
    val readFileUri: LiveData<Uri>
    private val repository : Repository

    init {
        val dbInstance = DataBase.getInstance(application)
        val userDao = dbInstance.UserDao()
        val ringDao = dbInstance.RingDao()
        repository = Repository(userDao, ringDao)
        readContactList = repository.getContacts
        readFileUri = repository.getUri()
    }

    suspend fun getContact(id:Long): LiveData<Contact>{
        return repository.getContact(id)
    }
...
}

in MainActivity I made this

setContent {
            FakeCallerTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colors.background
                ) {
                    val context = LocalContext.current
                    val roomViewModel: RoomViewModel = viewModel(
                        factory = RoomViewModelFactory(context.applicationContext as Application)
                    )
                    Greeting("Android")
                }

i think there is an issue with the context but i don't know really. still learning...

please help

Solution

This should help.

Modern day approach:

inside the plugins block,

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-kapt' //Add this
}

Then, withing dependencies,

    kapt "androidx.room:room-compiler:$rootProject.roomVersion"

Well based on the comment below,

These are all that I have needed to build fine.

    implementation "androidx.room:room-ktx:$rootProject.roomVersion"
    kapt "androidx.room:room-compiler:$rootProject.roomVersion"
    androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion"

Hey wait, are you connected to the internet? These may need to be downloaded from the web by the studio (downloads automatically). If download does not start, please check whether gradle is configured for offline work. If it is, toggle the state and it will download.

Per the comment below, this seems to have solved the issue

project-level-build{
 dependencies{
  classpath 'com.android.tools.build:gradle:7.1.0-alpha04' 
  classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 }
} 

Answered By - MARSK