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Throws

Platform and version requirements:
@Target([AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.CONSTRUCTOR]) annotation class Throws
Platform and version requirements: JVM (1.4)
typealias Throws = Throws
Platform and version requirements: Native (1.4)
@Target([AnnotationTarget.FUNCTION, AnnotationTarget.CONSTRUCTOR]) annotation class Throws
For JVM

This annotation indicates what exceptions should be declared by a function when compiled to a JVM method.

Example:

@Throws(IOException::class)
fun readFile(name: String): String {...}

will be translated to

String readFile(String name) throws IOException {...}
For Common

This annotation indicates what exceptions should be declared by a function when compiled to a platform method in Kotlin/JVM and Kotlin/Native.

For Native

This annotation indicates what exceptions should be declared by a function when compiled to a platform method.

When compiling to Objective-C/Swift framework, non-suspend functions having or inheriting this annotation are represented as NSError*-producing methods in Objective-C and as throws methods in Swift. Representations for suspend functions always have NSError*/Error parameter in completion handler

When Kotlin function called from Swift/Objective-C code throws an exception which is an instance of one of the exceptionClasses or their subclasses, it is propagated as NSError. Other Kotlin exceptions reaching Swift/Objective-C are considered unhandled and cause program termination.

Note: suspend functions without @Throws propagate only kotlin.coroutines.cancellation.CancellationException as NSError. Non-suspend functions without @Throws don't propagate Kotlin exceptions at all.

Constructors

Platform and version requirements: Native (1.0)

<init>

This annotation indicates what exceptions should be declared by a function when compiled to a platform method in Kotlin/JVM and Kotlin/Native.

<init>(vararg exceptionClasses: KClass<out Throwable>)

Properties

Platform and version requirements: Native (1.0)

exceptionClasses

the list of checked exception classes that may be thrown by the function.

vararg val exceptionClasses: Array<out KClass<out Throwable>>

© 2010–2020 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-throws/index.html