When using suspend fun in Room Dao methods, following error: Not sure how to convert a Cursor to this method's return type (java.lang.Object). [236612358]

Fixed

Bug

Status Update

No update yet.

Description

ja...@gmail.com

created issue #1

Jun 21, 2022 05:30AM

Component used: Room with suspend functions i.e. coroutines

error: /Users/jayshah/AndroidStudioProjects/SampleMemoryNotes/app/build/tmp/kapt3/stubs/debug/com/example/samplememorynotes/framework/db/NoteDao.java:17: error: Not sure how to convert a Cursor to this method's return type (java.lang.Object). public abstract java.lang.Object getNoteEntity(long id, @org.jetbrains.annotations.NotNull()

Usage:

// NoteDao.kt
@Dao
interface NoteDao {

    @Insert(onConflict = REPLACE)
    suspend fun addNoteEntity(noteEntity: NoteEntity)

    @Query("select * from note where id=:id")
    suspend fun getNoteEntity(id: Long): NoteEntity

    @Query("select * from note")
    suspend fun getAllNoteEntities(): List<NoteEntity>

    @Delete
    suspend fun deleteNoteEntity(noteEntity: NoteEntity)
}

Version used:

ext.coroutines_version = "1.3.0"
ext.room_version = "2.4.2"

    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"

    implementation "androidx.room:room-runtime:$room_version"
    kapt "androidx.room:room-runtime:$room_version"

    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    kapt "androidx.room:room-compiler:$room_version"
    implementation "androidx.room:room-ktx:$room_version"
    implementation "androidx.room:room-coroutines:2.1.0-alpha04"

Devices/Android versions reproduced on: Android emulator

If this is a bug in the library, we would appreciate if you could attach:

Sample project to trigger the issue: https://github.com/chetnashah/roomerrornotes
A screenrecord or screenshots showing the issue (if UI related):

Screenshot 2022-06-21 at 10.52.36 AM.png

1.4 MB

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Comments

ja...@gmail.com <ja...@gmail.com> #2Jun 21, 2022 05:43AM

There is no error when I use kotlin versions: 1.6.21, but issue/error starts appearing when kotlin version is 1.7.0

de...@gmail.com <de...@gmail.com> #3Jun 21, 2022 12:48PM

I have the same problem, i think no stable version of room 2.4.2 with kotlin 1.7.0

de...@gmail.com <de...@gmail.com> #4Jun 21, 2022 07:46PM

usage implementation 'androidx.room:room-ktx:2.5.0-alpha02'

ho...@gmail.com <ho...@gmail.com> #5Jun 22, 2022 09:25AM

me too

da...@google.com <da...@google.com> #6Jun 22, 2022 03:15PM

Thanks for the report I was able to reproduce the issue and indeed it occurs when using Kotlin 1.7.0. Sadly I don't have a workaround yet, but will investigate further.

da...@google.com <da...@google.com> #7Jun 22, 2022 03:32PM

and just to clarify, we see the issue when using Room 2.4.2, but not with Room 2.5.0-alpha02.

yy...@gmail.com <yy...@gmail.com> #8Jun 23, 2022 01:43AM

it occurs when kotlin version 1.7.0 and room 2.5.0-alpha02 as well to me. I solved the problem by downgrading kotlin version to 1.6.20

ma...@gmail.com <ma...@gmail.com> #9Jun 26, 2022 12:16PM

The same if you trying this Google-Developer Project:

https://github.com/google-developer-training/android-basics-kotlin-sql-basics-app
I updated everything - It wasn't running.
With ext.kotlin_version = "1.6.21" - it is running.

za...@gotocme.com <za...@gotocme.com> #10Jul 6, 2022 10:46AM

As a workaround, you can remove the "suspend" in the dao, but you need to explicitly specify the Dispatchers.IO when launching the coroutine.

da...@google.com <da...@google.com> #11Jul 6, 2022 12:51PM

Hey all, looks like the issue is related to a change in Kotlin's @Metadata annotation and the way Room reads it, Room 2.4.2 is using an older version of the kotlinx-metadata-jvm library which does not support reading Kotlin 1.7 information, where as in Room 2.5.0 we updated the library.

To workaround this issue please force upgrade the dependency by adding it to your annotation processor path, i.e. add kapt "org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.5.0" if you are using Room 2.4.x.

Meanwhile, I'll work on releasing a Room 2.4.3 that is compatible with Kotlin 1.7 since Room 2.5.x is still in development.

si...@gmail.com <si...@gmail.com> #12Jul 8, 2022 06:11AM

Thanks a lot. Now its working good for me.

zs...@gmail.com <zs...@gmail.com> #13Jul 11, 2022 04:22PM

Thanks! Do you think 2.4.3 is something that will be released in the next couple weeks? Trying to decide if I want to use the workaround or just wait until it is released.

da...@google.com <da...@google.com> #14Jul 11, 2022 05:17PM

We have an upcoming androidx release in July 20, I am trying to aim for that.

I also wanted to mention that if you migrate to using KSP instead of KAPT you won't run into this issue, as long as you use the KSP version that is compatible with Kotlin 1.7.0 which is 1.7.0-1.0.6.

ge...@gmail.com <ge...@gmail.com> #15Jul 26, 2022 07:02AM

It seems to be working with Kotlin 1.7.10

da...@google.com <da...@google.com> Jul 26, 2022 12:50PM

Marked as fixed.

19...@gmail.com <19...@gmail.com> #16Oct 19, 2022 01:07AM

thanks a lot..

pi...@gmail.com <pi...@gmail.com> #17Jul 7, 2023 11:06AM

Maybe reopen this.

@Query("SELECT * FROM ${SetupData.TABLE_NAME}")
suspend fun selectAll(): Cursor

[ksp] SetupDataDao.kt:24: Not sure how to convert a Cursor to this method's return type (android.database.Cursor).

Duh!

Room 2.5.2
Kotlin 1.9
KSP 1.9.0-1.0.11

te...@gmail.com <te...@gmail.com> #18Jul 11, 2023 11:29PM

I am experiencing the same issue again with the same versions as listed above. Quite frustrating!

da...@google.com <da...@google.com> #19Jul 12, 2023 01:26PM

The diagnosis is the same, Room needs to update its kotlinx-metadata-jvm dependency to be able to read Kotlin 1.9+ metadata. An upcoming patch release (Room 2.5.3) will have the dep updated.

da...@google.com <da...@google.com> #20Jul 12, 2023 01:28PM

Alternative if you use the KSP version of Room, this shouldn't be an issue.

io...@gmail.com <io...@gmail.com> #21Jul 19, 2023 11:26AM

I can confirm that using KSP version of Room the problem with Kotlin 1.9.0 disappears

ri...@gmail.com <ri...@gmail.com> #22Aug 4, 2023 05:04AM

I solved this by upgrading the room version with 2.6.0-alpha02

bl...@gmail.com <bl...@gmail.com> #23Aug 16, 2023 11:29AM

Comment has been deleted.

Message last modified on Aug 16, 2023 11:29AM

da...@davwheat.dev <da...@davwheat.dev> #24Aug 16, 2023 11:29AM

Is there any update on when a new 2.5.x Room version might be released? This is impacting one of our products' upgrades to Kotlin 1.9, and we'd rather not depend on an alpha version.

ra...@gmail.com <ra...@gmail.com> #25Sep 5, 2023 03:11PM

Any update on release of patch version 2.5.3 which will fix above? we are stuck with kotlin 1.9.0 upgrade. Also cannot use 2.6.0-alpha/beta versions as that is compiled against sdk 34. Please help with patch asap.

ma...@gmail.com <ma...@gmail.com> #26Sep 19, 2023 09:39AM

When will be ready the new version 2.6.0? I´ve seen in 2.6.0-beta01 the issue is fixed.

sh...@navi.com <sh...@navi.com> #27Oct 13, 2023 10:15AM

When will the stable version of 2.6.0 be rolled out ?
rc has been out since 20th sept

mr...@gmail.com <mr...@gmail.com> #28Jan 5, 2024 06:29AM

I met that problem again when I use 2022.3.1 Patch 3 Android Studio, Kotlin 1.9.0, Room 2.4.1. Glad I have to see this article that is solved

pa...@gmail.com <pa...@gmail.com> #29Feb 22, 2024 07:26PM

I was facing the same issue with kotlin version - 1.9.0 and room - 2.2.5. I upgraded the room version to 2.6.1 and now it's working absolutely file. So i would suggest to anyone facing this problem to look up for the current stable release for room via this article -

https://developer.android.com/jetpack/androidx/releases/room#2.3.0-beta02 and implementing upgrading the room version accordingly.

ah...@gmail.com <ah...@gmail.com> #30Sep 12, 2024 01:00PM

Same problem here, kotlin version - 1.9.10 and room - 2.5.2
Upgraded room to version to 2.6.1 and the issue is resolved!

ni...@gmail.com <ni...@gmail.com> #31Dec 19, 2024 12:25PM

Issue is still present if you want to return Cursor

Room 2.7.0-alpha12 kotlinVersion = "2.1.0" kspVersion = "2.1.0-1.0.29"

Sample: @Query("SELECT * FROM ${SetupData.TABLE_NAME}") suspend fun selectAll(): Cursor [ksp] Not sure how to convert a Cursor to this method's return type (android.database.Cursor).

co...@gmail.com <co...@gmail.com> #32Feb 11, 2025 05:24AM

#31 thank you it is working