Did someone ever experienced a situation where an `object` a

Question

Did someone ever experienced a situation where an `object` at runtime has multiple instances

orangy · Answer

This could be with multiple classloaders I think

brescia123 · Answer

I m not using classloaders

orangy · Answer

How do you know there are multiple instances What your code looks like

brescia123 · Answer

Thanks to the debugger

orangy · Answer

Well we might need some more information to help with diagnosing the problem What kind of picture you have in a debugger

orangy · Answer

Also is it reproducible I mean you see it all the time deterministically

brescia123 · Answer

I m using the `object` inside a `when` the object is a case of a sealed class and the `when` throws an exception `NoWhenBranchMatchedException` because it does not find a matching case the `when` is used as an expression and I m providing all the cases

brescia123 · Answer

Yes all the time I run that particular code

orangy · Answer

``` fun main args Array lt String gt val y S = S A val x = when y is S A gt 1 is S B gt 2 println x sealed class S object A S class B S ``` Is it like this This one works fine Anything special about your code

Andreas Sinz · Answer

< brescia123> try a full rebuild its possible that using when code with old compiled code produces that problem

brescia123 · Answer

I m no using `is` on case `S A`

brescia123 · Answer

< Andreas Sinz> I ll try thanks

orangy · Answer

Still without `is` it works fine for me There should be something special about your case

orangy · Answer

Did rebuild help Or are you still having the issue after rebuilding

Paul Woitaschek · Answer

It depends how you constrcut the instance

Paul Woitaschek · Answer

for example I had a situation where I used moshi like gson to deserialize a class

Paul Woitaschek · Answer

And it ended with an object that was not equal to the actual object class

paccman · Answer

Hi guys thanks for all your replies I m a colleague of < brescia123> < Andreas Sinz> < orangy> I did the rebuild but i still have different instance of same `object` that lead to `NoWhenBranchMatchedException` Sorry for too late response

orangy · Answer

That sounds scary We need to reproduce it Can you share at least some code that I can use to reproduce the problem Privately if you wish

Paul Woitaschek · Answer

You mean his case right That deserialization creates objects that differ is not scary for you right < orangy>

Paul Woitaschek · Answer

I mean objects could also generate an equals method that defines equals based upon it s class

Paul Woitaschek · Answer

```import com google common truth Truth assertThat import org junit Test object MyObject class T test fun main val original = MyObject val constructor = MyObject javaClass getDeclaredConstructor constructor isAccessible = true val throughReflection = constructor newInstance assertThat original isEqualTo throughReflection ```

Paul Woitaschek · Answer

That burned me once

orangy · Answer

Nope that reflection is not scary If you break the system by doing something like that you re off any guarantees slightly smiling face

Paul Woitaschek · Answer

Even though it s a common thing to do if you use stuff like gson moshi

Paul Woitaschek · Answer

So I d love if it would define equals based on the class

Paul Woitaschek · Answer

+ print it s class name instead of that ugly hashcode thingy in its toString

paccman · Answer

< orangy> i know that share some code should be the better solution I have to ask to my supervisors and due to some commitments it could take some days I ll update you asap

orangy · Answer

< Paul Woitaschek> please file find a feature request in our tracker that s the best way to have things moving

orangy · Answer

< paccman> thanks will be waiting

brescia123 · Answer

Hi < orangy> We found out what was the problem we defined the object `Serializable` to be able to put it inside an Android `Intent` and pass it between `Activity`s

orangy · Answer

So like < Paul Woitaschek> said you deserialized it Good that you ve found it

brescia123 · Answer

yep

brescia123 · Answer

I think that a IDE warning could be useful

brescia123 · Answer

when defining an `object` as `Serializable`

orangy · Answer

Please file an issue in YouTrack