Android: error: non-static type variable T cannot be referenced from a static context

Question

I have the following class:

@Parcelize
data class Collection<T : Parcelable> constructor(
    var models: List<T>,
    var cursor: String?
) : Parcelable

When I was using Kotlin 1.4.10, the project builds correctly without any errors, then I updated the project to Kotlin 1.4.21, and migrated to use kotlin-parcelize instead of kotlin-android-extensions, so after Kotlin update, when building the project I get the following errors:

> Task :domain:kaptDebugKotlin FAILED
/Library/DevelopmentArea/workspace/baaz_android_new/clean_domain/domain/build/tmp/kapt3/stubs/debug/com/myapp/domain/model/Collection.java:101: error: non-static type variable T cannot be referenced from a static context
        public final com.myapp.domain.model.Collection<T>[] newArray(int size) {
                                                                   ^/Library/DevelopmentArea/workspace/baaz_android_new/clean_domain/domain/build/tmp/kapt3/stubs/debug/com/myapp/domain/model/Collection.java:110: error: non-static type variable T cannot be referenced from a static context
        public final com.myapp.domain.model.Collection<T> createFromParcel(@org.jetbrains.annotations.NotNull()

Note: I'm using Android Studio 4.1.1

Probably the answer you are looking for can be found [here](https://stackoverflow.com/a/65320843/3102234) — Horațiu Udrea, Dec 22 '20 at 10:47
Does this answer your question? [Migrate to the new kotlin-parcelize](https://stackoverflow.com/questions/64991110/migrate-to-the-new-kotlin-parcelize) — Horațiu Udrea, Dec 22 '20 at 10:49
You cannot use an interface as a generic while implementing the same interface, instead, it is better to use a type for the list which implements Parcelable — alireza rahmaty, Dec 22 '20 at 10:57
It's fixed in Kotlin `1.5.0`. Tested in Android Studio `4.2.1` with Kotlin plugin `1.5.0`. — Myroslav, May 17 '21 at 14:57

score 1 · Answer 1 · answered Dec 23 '20 at 07:58

Currently to fix the errors that I get, and meanwhile, keep using Kotlin 1.4.21, I just removed the @Parcelize annotation from any class with a generic type usage like the one in the question, and just implemented the Parcelable with the old way like the following:

    data class Collection<T> constructor(
    var models: List<T>,
    var cursor: String?
) : Parcelable {

    constructor(parcel: Parcel) : this(
        mutableListOf<T>().also { list: List<T> ->
            parcel.readList(list, Collection<T>::models.javaClass.classLoader)
        },
        parcel.readString())

    override fun writeToParcel(parcel: Parcel, flags: Int) {
        parcel.writeList(models)
        parcel.writeString(cursor)
    }

    override fun describeContents(): Int = 0

    companion object {

        @JvmField
        val CREATOR = object : Parcelable.Creator<Collection<Parcelable>> {
            override fun createFromParcel(source: Parcel): Collection<Parcelable> {
                return Collection(source)
            }

            override fun newArray(size: Int): Array<Collection<Parcelable>?> {
                return arrayOfNulls(size)
            }
        }
    }
}

now its throwing `Caused by android.os.BadParcelableException: ClassNotFoundException when unmarshalling:` on the `readList` line, any ideas? — CHAN, Mar 09 '21 at 07:32

Android: error: non-static type variable T cannot be referenced from a static context

1 Answers1