Pre-Populating ROOM Database results in "java.lang.RuntimeException: Unable to copy database fi-CodePudding

I'm currently trying to pre-populate a ROOM database from a database file within assets using .createFromAsset. While running my application, I get "Caused by: java.lang.RuntimeException: Unable to copy database file." error.

My db file path assets/database/cardb.db

E/AndroidRuntime: FATAL EXCEPTION: arch_disk_io_0
    Process: com.example.myapplication, PID: 8068
    java.lang.RuntimeException: Exception while computing database live data.
        at androidx.room.RoomTrackingLiveData.refreshRunnable$lambda-0(RoomTrackingLiveData.kt:74)
        at androidx.room.RoomTrackingLiveData.$r8$lambda$UkyPj-RMUoTXOMbUuy5NWSwmo0E(Unknown Source:0)
        at androidx.room.RoomTrackingLiveData$$ExternalSyntheticLambda0.run(Unknown Source:2)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
        at java.lang.Thread.run(Thread.java:1012)
     Caused by: java.lang.RuntimeException: Unable to copy database file.
        at androidx.room.SQLiteCopyOpenHelper.verifyDatabaseFile(SQLiteCopyOpenHelper.kt:114)
        at androidx.room.SQLiteCopyOpenHelper.getWritableDatabase(SQLiteCopyOpenHelper.kt:68)
        at androidx.room.RoomDatabase.inTransaction(RoomDatabase.kt:629)
        at androidx.room.RoomDatabase.assertNotSuspendingTransaction(RoomDatabase.kt:448)
        at androidx.room.RoomDatabase.query(RoomDatabase.kt:477)
        at androidx.room.util.DBUtil.query(DBUtil.kt:75)
        at com.example.myapplication.data.CarDao_Impl$1.call(CarDao_Impl.java:34)
        at com.example.myapplication.data.CarDao_Impl$1.call(CarDao_Impl.java:31)
        at androidx.room.RoomTrackingLiveData.refreshRunnable$lambda-0(RoomTrackingLiveData.kt:72)
        at androidx.room.RoomTrackingLiveData.$r8$lambda$UkyPj-RMUoTXOMbUuy5NWSwmo0E(Unknown Source:0) 
        at androidx.room.RoomTrackingLiveData$$ExternalSyntheticLambda0.run(Unknown Source:2) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637) 
        at java.lang.Thread.run(Thread.java:1012) 
     Caused by: java.io.FileNotFoundException: database/cardb.db
        at android.content.res.AssetManager.nativeOpenAsset(Native Method)
        at android.content.res.AssetManager.open(AssetManager.java:904)
        at android.content.res.AssetManager.open(AssetManager.java:881)
        at androidx.room.SQLiteCopyOpenHelper.copyDatabaseFile(SQLiteCopyOpenHelper.kt:156)
        at androidx.room.SQLiteCopyOpenHelper.verifyDatabaseFile(SQLiteCopyOpenHelper.kt:111)
        at androidx.room.SQLiteCopyOpenHelper.getWritableDatabase(SQLiteCopyOpenHelper.kt:68) 
        at androidx.room.RoomDatabase.inTransaction(RoomDatabase.kt:629) 
        at androidx.room.RoomDatabase.assertNotSuspendingTransaction(RoomDatabase.kt:448) 
        at androidx.room.RoomDatabase.query(RoomDatabase.kt:477) 
        at androidx.room.util.DBUtil.query(DBUtil.kt:75) 
        at com.example.myapplication.data.CarDao_Impl$1.call(CarDao_Impl.java:34) 
        at com.example.myapplication.data.CarDao_Impl$1.call(CarDao_Impl.java:31) 
        at androidx.room.RoomTrackingLiveData.refreshRunnable$lambda-0(RoomTrackingLiveData.kt:72) 
        at androidx.room.RoomTrackingLiveData.$r8$lambda$UkyPj-RMUoTXOMbUuy5NWSwmo0E(Unknown Source:0) 
        at androidx.room.RoomTrackingLiveData$$ExternalSyntheticLambda0.run(Unknown Source:2) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637) 
        at java.lang.Thread.run(Thread.java:1012)

Directories

Here is my database file

package com.example.myapplication.data

import android.content.Context
import android.os.Bundle
import android.util.Log
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase
import java.io.File


@Database(entities = [CarMake::class], version = 1, exportSchema = false)
abstract class CarDatabase: RoomDatabase() {
    abstract fun carDao(): CarDao

    companion object{

        @Volatile
        private var INSTANCE : CarDatabase? = null

        fun provideDatabase(context : Context): CarDatabase{
            //Log.d("MyActivity", context.toString())


            val tempInstance = INSTANCE
            if (tempInstance != null){
                return tempInstance
            }
            synchronized(this){

                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    CarDatabase::class.java,"car_database")
                    .createFromAsset("database/cardb.db")
                    .build()
                INSTANCE = instance
                return instance
            }

        }

    }
}

I tried recreating the database file in case I did something wrong. I am able to open it up and see the structure and data within an SQLite browser. I also tried renaming the database file, moving the db just inside of the assets folder. Furthermore, I tried looking into my app data within the virtual device and the database is not present in the assets folder. I expect for the database to simply be copied and function the way it is intended to.

I've read some posts regarding this issue.

CodePudding user response：

According to your screenshot, your assets/ directory is in the androidTest source set. That needs to be moved to the main source set.