Hands-On Microservices with Kotlin

Publishing a single object

Reactor provides a way to define a reactive publisher through a class named Mono, but that publisher can only send one result.

To create a Mono, we can simply do this:

val customerMono : Mono<Customer> = Mono.just(Customer(1, "Mono"))

But reactor provides a high-level function for Kotlin that we can use to take advantage of more Kotlin characteristics:

val customerMono : Mono<Customer> = Customer(1, "Mono").toMono()

But since Kotlin has type inference, we can simply write it as:

val customerMono = Customer(1, "Mono").toMono()

What we should understand is that a Mono is not actually the value of the Customer instance that we create, it is a promise of what we are going to get. When we declare something as Mono<Customer> ...