What is going on with RoomDB and Kotlin coroutines? I am trying again and again to use suspend function in Room Dao but everytimes it shows error. I even follow the android codelabs example. But it shows error again. the app don't even build if I write suspend in Dao. But if I remove suspend keyword it build 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"
}

CodePudding user response：

Try to change your dependencies this way :

// Room
implementation("androidx.room:room-runtime:$rootProject.roomVersion")
kapt("androidx.room:room-compiler:$rootProject.roomVersion")
implementation("androidx.room:room-ktx:$rootProject.roomVersion")
testImplementation("androidx.room:room-testing:$rootProject.roomVersion")

Then try to clean and rebuild project, from the Build menu.

CodePudding user response：

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'