Android room persistent: AppDatabase_Impl does not exist
In Android Studio, if you get errors when you paste code or during the build process, select Build >Clean Project. Then select Build > Rebuild Project, and then build again.
UPDATE
If you have migrated to androidx
def room_version = "2.3.0" // check latest version from docs implementation "androidx.room:room-runtime:$room_version" kapt "androidx.room:room-compiler:$room_version" UPDATE 2 (since July 2021)
def room_version = "2.3.0" // check latest version from docs implementation "androidx.room:room-ktx:$room_version" kapt "androidx.room:room-compiler:$room_version" Thanks a lot. Just moving to Kotlin and all my test cases started failing. Was banging my head. Then I accidentally saw this comment. Saved my day.
This saved me. I think Google should work more on showing proper error. I had kapt call but I didnt add apply kapt-plugin
Was stuck since yesterday. thanks a lot. I don’t understand why don’t google people mention this in the documentation.
And keep both in dependencies
annotationProcessor "android.arch.persistence.room:compiler:$rootProject.roomVersion" kapt "android.arch.persistence.room:compiler:$rootProject.roomVersion" In newer version don’t need to add both dependencies at a time Just use, hope it will work.
kapt 'android.arch.persistence.room:compiler:1.1.1' I had this error when I missed
is properly defined and you’d be good
For clarity, this goes immediately above the DB class definition. It appears to have fixed my problem — thanks!
make sure you don’t have empty constructors (constructor()<>) in your entities stackoverflow.com/a/60494924/6148931
I had this problem and changing the build.gradle as the accepted answer did not solve the problem. Adding this annotation solved the problem, but in the tutorial I was following, the «user» class has only @Entity , not @Entity(tablename=»table name» ) . If this is required, why does the tutorial lack this annotation?
if you are using kotlin classes to implement database then use
kapt "android.arch.persistence.room:compiler:1.1.1" in your gradle file, it will work.
I think most of the people were not using androidx library in whole project. that why I suggested 1.1.1. I myself faced compilation issues and felt safe with minimal changes using older version.
For Kotlin Developers
implementation "android.arch.persistence.room:runtime:1.0.0" kapt "android.arch.persistence.room:compiler:1.0.0" And add apply plugin: ‘kotlin-kapt’ to the top of the app level build.gradle .
For Java Developers
implementation "android.arch.persistence.room:runtime:1.0.0" annotationProcessor "android.arch.persistence.room:compiler:1.0.0" Agreed with the above answers
The solution is as below. Change annotationProcessor to kapt as below
// annotationProcessor "androidx.room:room-compiler:$room_version" implementation "androidx.room:room-runtime:$room_version" kapt "androidx.room:room-compiler:$room_version" It is not just about updating your dependencies. Make sure all your Room dependencies have the same version.
implementation 'android.arch.persistence.room:rxjava2:1.1.0-alpha2' implementation 'android.arch.persistence.room:runtime:1.1.0-alpha2' annotationProcessor "android.arch.persistence.room:compiler:1.1.0-alpha2" In the sample snippet above, all my Room dependencies have the same version 1.1.0-alpha2
If you are using kotlin , add kotlin annotation processor plugin to app level build.gradle
Also remove annotationProcessor and replace it with kapt
The annotationProcessor only works in java environment. The kapt takes care of both java and kotlin. If something wrong with your implementation, those plugins will show them at the compile time.
tried adding plugins <. >and replacing kapt with annotationProcessor but separately, thank you very much for answering..
I meet with the problem, because I forget @Dao annotation
@Dao public interface SearchHistoryDao < @Query("SELECT * FROM search_history") ListgetAll(); @Insert void insertAll(SearchHistory. histories); @Delete() void delete(SearchHistory history); > make sure to add correct dependency for room in build.gradle
ext < roomVersion = '2.1.0-alpha06' >// Room components implementation "androidx.room:room-runtime:$rootProject.roomVersion" implementation "androidx.room:room-ktx:$rootProject.roomVersion" kapt "androidx.room:room-compiler:$rootProject.roomVersion" androidTestImplementation "androidx.room:room-testing:$rootProject.roomVersion" And below line at the top-
I met this problem because I have forgotten the apt dependences
implementation "android.arch.lifecycle:extensions:$archLifecycleVersion" implementation "android.arch.persistence.room:runtime:$archRoomVersion" annotationProcessor "android.arch.lifecycle:compiler:$archLifecycleVersion" annotationProcessor "android.arch.persistence.room:compiler:$archRoomVersion" after added the annotationProcessor, and rebuild it, the problem solved.
Had the same problem. Implemented the few classes and interface as officially told in a new example project created by Android Studio: https://developer.android.com/training/data-storage/room/
All mentioned solutions above did not help, the necessary _Impl files according to my database class were not generated by Room. Finally executing gradle clean build in terminal gave me the hint that lead to the solution:
«warning: Schema export directory is not provided to the annotation processor so we cannot export the schema. You can either provide room.schemaLocation annotation processor argument OR set exportSchema to false.»
I added the parameter exportSchema = false in the database class
@Database(entities = arrayOf(User::class), version = 1, exportSchema = false) abstract class AppDatabase : RoomDatabase()
And then it worked, found these two generated files in the app module under generatedJava:
cannot find implementation for database Room
I am writing my first application with Room. I discovered it has issues when it uses kotlin, even some sample doesn’t work on my machine, so I rollback to plain Java.
FilmsDatabaseJ db = Room.databaseBuilder(getApplicationContext(), FilmsDatabase.class, "DATABASE_NAME").build(); java.lang.RuntimeException: cannot find implementation for com.home.myapplication.films.storage.FilmsDatabase. FilmsDatabase_Impl does not exist I explored source code, Room expects to have such class already (does generated somewhere?), but by some reason such class doesn’t exist for my case which is not far from documentation. Could you please share your ideas what might went wrong here?
@TypeConverters() @Database(entities = , version = 1) public abstract class FilmsDatabaseJ extends RoomDatabase < private static final String DATABASE_NAME = "DATABASE_NAME"; private static FilmsDatabaseJ instance; public abstract FilmsDaoJ getFilmsDao(); @NotNull public static FilmsDatabaseJ getInstance(Context context) < if (instance == null) < synchronized (FilmsDatabaseJ.class) < if (instance != null) return instance = Room.databaseBuilder(context, FilmsDatabaseJ.class, DATABASE_NAME).build(); >> return instance; > > annotationProcessor "android.arch.lifecycle:compiler:1.1.1" // Room (use 1.1.0-beta2 for latest beta) implementation "android.arch.persistence.room:runtime:1.0.0" annotationProcessor "android.arch.persistence.room:compiler:1.0.0" Room «cannot find implementation for» even with using kapt
I am trying to use Room in my project. Gradle syncing files well, but I get RunitomeException when trying to get database instance. «Caused by: java.lang.RuntimeException: cannot find implementation for com.fillooow.android.testtochka.BusinessLogic.database.GithubUserSearchDataBase. GithubUserSearchDataBase_Impl does not exist» I searched this issue and find that solution is to add this lines into build.gradle file:
implementation "android.arch.persistence.room:runtime:1.1.1" implementation "android.arch.persistence.room:rxjava2:1.1.1" kapt "android.arch.persistence.room:compiler:1.1.1" apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions' apply plugin: 'kotlin-kapt' android < compileSdkVersion 28 defaultConfig < applicationId "com.fillooow.android.testtochka" minSdkVersion 21 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' >> > dependencies import android.arch.persistence.room.Room import android.arch.persistence.room.RoomDatabase import android.content.Context abstract class GithubUserSearchDataBase : RoomDatabase() < abstract fun githubUserSearchDataDao(): GithubUserSearchDataDao companion object < private var INSTANCE: GithubUserSearchDataBase? = null fun getInstance(context: Context): GithubUserSearchDataBase?< if (INSTANCE == null)< synchronized(GithubUserSearchDataBase::class)< INSTANCE = Room.databaseBuilder(context.applicationContext, GithubUserSearchDataBase::class.java, "github.db") .build() >> return INSTANCE > fun destroyInstance() < INSTANCE = null >> > I try to implement a Room Database with Androidx, I am getting error
java.lang.RuntimeException: cannot find implementation for com.qbitstream.salesmanagementsystem.data.AppDatabase. AppDatabase_Impl does not exist at androidx.room.Room.getGeneratedImplementation(Room.java:94)
apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions' android < compileSdkVersion 28 defaultConfig < applicationId "com.qbitstream.salesmanagementsystem" minSdkVersion 19 targetSdkVersion 28 versionCode 1 versionName "1.0" testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" >buildTypes < release < minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' >> > dependencies < def nav_version = "1.0.0-alpha04" implementation fileTree(dir: 'libs', include: ['*.jar']) implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version" implementation 'androidx.appcompat:appcompat:1.0.0-rc01' implementation 'androidx.constraintlayout:constraintlayout:1.1.2' implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0-rc01' implementation 'androidx.legacy:legacy-support-v4:1.0.0-rc01' testImplementation 'junit:junit:4.12' androidTestImplementation 'androidx.test:runner:1.1.0-alpha4' androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4' implementation "android.arch.navigation:navigation-fragment:$nav_version" // use -ktx for Kotlin implementation "android.arch.navigation:navigation-ui:$nav_version" // use -ktx for Kotlin //room def room_version = "2.0.0-rc01" implementation "androidx.room:room-runtime:$room_version" annotationProcessor "androidx.room:room-compiler:$room_version" // use kapt for Kotlin // optional - RxJava support for Room implementation "androidx.room:room-rxjava2:$room_version" // optional - Guava support for Room, including Optional and ListenableFuture implementation "androidx.room:room-guava:$room_version" // Test helpers testImplementation "androidx.room:room-testing:$room_version" // retrofit implementation "com.squareup.retrofit2:retrofit:2.3.0" implementation "com.squareup.retrofit2:adapter-rxjava2:2.3.0" implementation "com.squareup.retrofit2:converter-gson:2.3.0" // rxandroid implementation "io.reactivex.rxjava2:rxandroid:2.0.1" >import android.content.Context import androidx.room.Database import androidx.room.Room import androidx.room.RoomDatabase import com.qbitstream.salesmanagementsystem.model.Customer @Database(entities = [(Customer::class)], version = 1) abstract class AppDatabase: RoomDatabase() < abstract fun customerDao(): CustomerDao companion object < @Volatile private var INSTANCE: AppDatabase? = null fun getInstance(context: Context): AppDatabase = INSTANCE ?: synchronized(this) < INSTANCE ?: buildDatabase(context).also < INSTANCE = it >> private fun buildDatabase(context: Context) = Room.databaseBuilder(context.applicationContext, AppDatabase::class.java, "sms.db") .build() > > import androidx.room.Dao import androidx.room.Insert import androidx.room.OnConflictStrategy import androidx.room.Query import com.qbitstream.salesmanagementsystem.model.Customer @Dao interface CustomerDao < @Insert(onConflict = OnConflictStrategy.IGNORE) fun insertAll(customer:List) @Query("SELECT * FROM customer where lower(customer_name) like ':name%'") fun customers(name:String):List > import androidx.room.ColumnInfo import androidx.room.Entity import androidx.room.PrimaryKey import com.google.gson.annotations.SerializedName data class Customers(val customer: Data,val response_code:Int,val status:String) data class Data(val data:ArrayList) @Entity(tableName = "customer") data class Customer( @PrimaryKey @ColumnInfo(name = "id") @SerializedName("id") val id:String, @ColumnInfo(name = "customer_name") @SerializedName("customer_name") val name:String) data class Manufacturer(val id:Int,val name:String) data class Product(val id:Int,val manufacturerId: Int,val name:String)