a.zampa

a.zampa

Kotlin and Android Development featuring Jetpack: error concerning function getCurrentStandings in BaseballDao.java

@mfazio23

I’m following the indications of the book and arriver ad chapter 10, but the app cannot be compiled due to an error in the BaseballDao.java class produced during the build process. I get the following errors:

  • Not sure how to convert a Cursor to this method’s return type (java.lang.Object).
  • Query method parameters should either be a type that can be converted into a database column or a List / Array that contains such type. You can consider adding a Type Adapter for this.
  • Unused parameter: continuation
  • Type of the parameter must be a class annotated with @Entity or a collection/array of it.
  • Not sure how to handle insert method’s return type.
  • Type of the parameter must be a class annotated with @Entity or a collection/array of it.
  • Not sure how to handle insert method’s return type.
  • Type of the parameter must be a class annotated with @Entity or a collection/array of it.
  • Not sure how to handle update method’s return type. Currently the supported return types are void, int or Int.
  • Type of the parameter must be a class annotated with @Entity or a collection/array of it.
  • Not sure how to handle update method’s return type. Currently the supported return types are void, int or Int.
  • The query returns some columns [teamId, division, wins, losses, winsLastTen, streakCount, streakType, divisionGamesBack, leagueGamesBack, id] which are not used by java.lang.Object. You can use @ColumnInfo annotation on the fields to specify the mapping. You can annotate the method with @RewriteQueriesToDropUnusedColumns to direct Room to rewrite your query to avoid fetching unused columns. You can suppress this warning by annotating the method with @SuppressWarnings(RoomWarnings.CURSOR_MISMATCH). Columns returned by the query: teamId, division, wins, losses, winsLastTen, streakCount, streakType, divisionGamesBack, leagueGamesBack, id.

The error message is

C:\Users\ale\AndroidStudioProjects\AndroidBaseballLeague\app\build\tmp\kapt3\stubs\debug\org\mathverse\androidbaseballleague\data\BaseballDao.java:31: error: Not sure how to convert a Cursor to this method’s return type (java.lang.Object).
public abstract java.lang.Object getCurrentStandings(@org.jetbrains.annotations.NotNull()

(I’m using org.mathverse.androidbaseballleague as package name, instead of dev.mfazio.abl).

The BaseballDao.java class contains the following lines

@org.jetbrains.annotations.Nullable()
@androidx.room.Query(value = "SELECT * FROM standings")
public abstract java.lang.Object getCurrentStandings(@org.jetbrains.annotations.NotNull()
kotlin.coroutines.Continuation<? super java.util.List<org.mathverse.androidbaseballleague.standings.TeamStanding>> continuation);

This is the only function of the database having prblems.
How can I solve this issue?
Thanks

Marked As Solved

a.zampa

a.zampa

Michael,

according to comment #11 to issue number 236612358, this problem is related to a change to Kotlin @Metadata annotation and can be solved forcing the dependency to the new version of kotlinx-metadata-jvm by adding

kapt “org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.5.0”

This worked for me and solved another issue (room 2.4.2 didn’t allow to use vals into @Entity data classes asking, for the generated java class, setters for the corresponding variables).

Where Next?

Popular Pragmatic Bookshelf topics Top

jimschubert
In Chapter 3, the source for index introduces Config on page 31, followed by more code including tests; Config isn’t introduced until pag...
New
mikecargal
Title: Hands-On Rust (Chap 8 (Adding a Heads Up Display) It looks like ​.with_simple_console_no_bg​(SCREEN_WIDTH*2, SCREEN_HEIGHT*2...
New
jdufour
Hello! On page xix of the preface, it says there is a community forum "… for help if your’re stuck on one of the exercises in this book… ...
New
alanq
This isn’t directly about the book contents so maybe not the right forum…but in some of the code apps (e.g. turbo/06) it sends a TURBO_ST...
New
jeremyhuiskamp
Title: Web Development with Clojure, Third Edition, vB17.0 (p9) The create table guestbook syntax suggested doesn’t seem to be accepted ...
New
AndyDavis3416
@noelrappin Running the webpack dev server, I receive the following warning: ERROR in tsconfig.json TS18003: No inputs were found in c...
New
jskubick
I’m running Android Studio “Arctic Fox” 2020.3.1 Patch 2, and I’m embarrassed to admit that I only made it to page 8 before running into ...
New
jgchristopher
“The ProductLive.Index template calls a helper function, live_component/3, that in turn calls on the modal component. ” Excerpt From: Br...
New
jskubick
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
mert
AWDWR 7, page 152, page 153: Hello everyone, I’m a little bit lost on the hotwire part. I didn’t fully understand it. On page 152 @rub...
New

Other popular topics Top

Devtalk
Hello Devtalk World! Please let us know a little about who you are and where you’re from :nerd_face:
New
PragmaticBookshelf
Andy and Dave wrote this influential, classic book to help their clients create better software and rediscover the joy of coding. Almost ...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
Exadra37
Oh just spent so much time on this to discover now that RancherOS is in end of life but Rancher is refusing to mark the Github repo as su...
New
PragmaticBookshelf
Build highly interactive applications without ever leaving Elixir, the way the experts do. Let LiveView take care of performance, scalabi...
New
AstonJ
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
New
PragmaticBookshelf
Leverage Elixir and the Nx ecosystem to build intelligent applications that solve real-world problems in computer vision, natural languag...
New
First poster: AstonJ
Jan | Rethink the Computer. Jan turns your computer into an AI machine by running LLMs locally on your computer. It’s a privacy-focus, l...
New
PragmaticBookshelf
Build modern server-driven web applications using htmx. Whatever programming language you use, you’ll write less (and cleaner) code. ...
New

Sub Categories: