kotlin - Passing null as part of vararg parameter to Java method from Kotlin

Question

I have something similar to this method declaration in Java. Let's say the class is named JavaClass:

public T execute(String s, Function<T> f, Object... args) {}

If I want to call this from Kotlin (my version is 1.2.21), I could write something similar to this:

val arg1 = ""
val arg2: String? = null
val javaObject = JavaClass()

javaObject.execute("some string", { print(it) }, arg1, arg2)

The strange thing is that I get an IllegalStateException when executing this code. It says arg2 must not be null. I could understand if it said that args must not be null. But considering that this call would result in the array looking like ["", null], which in Java is perfectly fine, this seems very strange.

I need to be able to pass null values to this method. What do I need to do to fix this behaviour?

Answer 1

此类调用的IllegalStateException抛出意味着该方法已返回 null 并且您将返回值分配给非 null 类型的变量。它与可变参数无关。