Kotlin - Throw Custom Exception

Question

How can I throw a custom exception in Kotlin? I didn't really get that much off the docs...

In the docs, it gets described what each exception needs, but how exactly do I implement it?

Answer 1

One thing to keep in mind: if you are using the IntelliJ IDE, just a simple copy/paste of Java code can convert it to Kotlin.

Coming to your question, now. If you want to create a custom Exception, just extend Exception class like:

class TestException(message:String): Exception(message) 

and throw it like:

throw TestException("Hey, I am testing it") 

Answer 2

Most of these answers just ignore the fact that Exception has 4 constructors. If you want to be able to use it in all cases where a normal exception works do:

class CustomException : Exception {     constructor() : super()     constructor(message: String) : super(message)     constructor(message: String, cause: Throwable) : super(message, cause)     constructor(cause: Throwable) : super(cause) } 

this overwrites all 4 constructors and just passes the arguments along.

EDIT: Please scroll down to R. Agnese answer, it manages to do this without overriding 4 constructors which is error prone.