kotlin function default arguments from java

Question

given following Kotlin class:

class Foo {
   public fun bar(i: Int = 0): Int = 2 * i
}

How should I call 'bar' function without any parameter from a java/groovy code?

def f = new Foo()
f.bar() //throws:  java.lang.IllegalArgumentException: Parameter specified as non-null contains null

question from:https://stackoverflow.com/questions/17348084/kotlin-function-default-arguments-from-java

Answer 1

You can do this now in Kotlin. For your class method, use the @JvmOverloads annotation.

class Foo {
    @JvmOverloads public fun bar(name: String = "World"): String = "Hello $name!"
}

Now simply call it from Java:

Foo foo = new Foo();
System.out.println(foo.bar());
System.out.println(foo.bar("Frank"));

Outputs the following:

Hello World!

Hello Frank!