I'm new to Android development and I'm currently building my first real app. I'm trying to implement a MVVM architecture and because of that I'm having a viewModel for each fragment and each viewModel has a viewModelFactory. At least, this is how I understood it has to be.
I use the boilerplate code everyone seems to use for the factory:
class ExampleViewModelFactory(private val exampleDao: ExampleDao) : ViewModelProvider.Factory {
override fun <T : ViewModel> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(exampleViewModel::class.java)) {
@Suppress("UNCHECKED_CAST")
return ExampleViewModel(exampleDao) as T
}
throw IllegalArgumentException("Unknown ViewModel class")
}
}
Now the problem is, that the compiler is giving me the following error:
e: C:\Users\ ...\ExampleViewModel.kt: (64, 7): Inheritance from an interface with '@JvmDefault' members is only allowed with -Xjvm-default option
And this error is produced by the viewModelFactory class I have implemented in the viewModel. I really can't tell what this means and I cant find anything helpful or even related to my specific problem. I basically followed some basic tutorials about creating your first app, but I keep on running into errors like this. In most cases, I was able to fix the problem by myself, but this time it's different.
I know that a lot of you have a lot of experience and knowledge, so I hope that some of you find the time to help me and give me a hint what I can do to fix this.
It seems like you are either directly or indirectly (through some other library) depending on Lifecycle 2.5.0-alpha01.
As per this issue:
You need to temporarily add following to your
build.gradle:tasks.withType(KotlinCompile).configureEach { kotlinOptions { freeCompilerArgs += [ "-Xjvm-default=all", ] } }Note that in certain circumstances you may want to use
all-compatibilityinstead ofall, learn more about that in Jebrain's blogpost.Starting with kotlin 1.6.20 you won't need touch build.gradle for more information see KT-47000
Kotlin version (kts) of @ianhanniballake's answer
tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile::class).configureEach {
kotlinOptions {
freeCompilerArgs = freeCompilerArgs + "-Xjvm-default=all"
}
}
Try putting these line inside of android{} block in module build.gradle file
kotlinOptions{
freeCompilerArgs += [
"-Xjvm-default=all",
]
}
If above code doesn't work try adding these below lines inside dependencies{} block
tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).configureEach{
kotlinOptions{
freeCompilerArgs +=["-Xjvm-default=all",]
}
}
Use the stable version, in this case 2.4.1. I have the same problem and I solved it by making this change.
https://developer.android.com/jetpack/androidx/releases/lifecycle