Accessing Kotlin class object from Java

Question

I have a Kotlin class which has a class object, eg

public class Foo {
    public class object {
        public val SomeValue : Int = 0
    }
}

If I'm using this class from Java, how do I access SomeValue inside the class object? If it were a Java class with a static property, I'd just use Foo.SomeValue - but I can't do that here.

IntellIJ shows that I can access Foo.object.$instance , but $instance doesn't have getSomeValue or anything like that. If I try to use $instance.SomeValue anyway, when I build the error message says:

SomeValue has private access in Foo.object

I'm using Kotlin 0.5.1.

Answer 1

作为一种解决方法，您应该能够使用@JvmField使 Kotlin 字段可见：

@JvmField var addressLocationBox: ToOne? = null

Answer 2

The "absense" of getSomeValue() is a bug in the IDE. If you use it, it compiles OK. I created an issue: http://youtrack.jetbrains.com/issue/KT-3337

Answer 3

data class YourClass(@JvmField val name: String)

Answer 4

To set a custom name for the generated Java class, use the @JvmName annotation:

Kotlin

@file:JvmName("DemoUtils")

package com.example

class Util

fun getTime() { /*...*/ }

Java

new com.example.Util();
com.example.DemoUtils.getTime();

Moreover, if you use the @JvmMultifileClass , then:

@file:JvmName("Utils")
@file:JvmMultifileClass

package com.example

fun getDate() { /*...*/ }

Java

com.example.Utils.getDate();