Hands-On Object-Oriented Programming with Kotlin

Interoperability

Kotlin is a language that is designed to maintain interoperability with Java code. The following example shows a nuance that we should take into account when we invoke Kotlin code from Java code. Let's create a simple Kotlin function that throws an exception:

fun testMethod() {    throw IOException()}

This function can be called from Java code like this:

public class Example5 {    public static void main(String[] args) {        Example5Kt.testMethod();    }}

And this code can be compiled. This behavior can be unexpected for a Java developer who is used to dealing with checked exceptions. See what happens if we write something like this:

public static void testMethod() {    throw new IOException();}

The compiler will show the following error: ...