Singleton serialization in Kotlin

Question

I'm wondering if it's possible in Kotlin to deserialize (restore property values) of a declared object, without having to manually assign the properties or resorting to reflection. The following snippet further explains:

object Foo: Serializable {
    var propOne: String = ""
    // ...

    fun persist() {
        serialize(this) 
        // no problem with serialization
    }

    fun restore(bytes: ByteArray) {

        val fooObj: Foo = deserialize(bytes) as Foo
        // It seems Kotlin allows us to use singleton as type!

        // obvioulsly either of the following is wrong:
        // this = fooObj
        // Foo = fooObj

        // ... is there a way to 'recover' the singleton (object) other than 
        //     manual assignment of properties (or reflection) ???    
    }
}

Answer 1

There is no way to reassign the global reference to a singleton with a new instance. At most you can write out the properties during serialization, and then on deserialization directly read the properties and mutate the state in the original object. It will require custom code for you to assign the properties into the object either by direct assignment or reflection. It would be better if you make your own singleton mechanism that holds an instance that you can swap out to be another instance that you deserialize.