Room + cannot find implementation DB + DB_Impl does not exist : <p>I am getting following error while running application</p>

<pre><code>java.lang.RuntimeException: cannot find implementation for com.abc.db.abdDB. abcDB_Impl does not exist
</code></pre>

<p>My build.gradle has following configuration:</p>

<pre><code>implementation "androidx.lifecycle:lifecycle-extensions:2.0.0-alpha1"
annotationProcessor "androidx.lifecycle:lifecycle-compiler:2.0.0-alpha1"
implementation "androidx.room:room-runtime:2.0.0-alpha1"
annotationProcessor "androidx.room:room-compiler:2.0.0-alpha1"
</code></pre>

<p>My Database class:</p>

<pre><code>fun getDatabase(context: Context): abcDB? {
        if (dbInstance == null) {
            synchronized(abcDB::class.java) {
                if (dbInstance == null) {
                    dbInstance = Room.databaseBuilder(context.applicationContext,
                            abcDB::class.java, "abc_db")
                            .fallbackToDestructiveMigration()
                            .addCallback(sRoomDatabaseCallback)
                            .build()
                }
            }
        }
        return dbInstance
    }
</code></pre>

<p>Does anyone try to use androidX API? Can someone help to find solution for this?</p>
