How to get value from a Mono subscribe call

Question

I have something like this:

mono.subscribe(val -> doSomething(val));

doSomething returns an integer. I would get and return that integer, or a Mono<int>. How can I do?

Answer 1

To return Mono<Integer> you can do the following:

Mono<Integer> result = mono.map(value -> doSomething(value));

But remember that in Reactor, nothing happens until subscribe, so don't forget to subscribe:

result.subscribe(System.out::println);

If you want to get an integer out of mono, then you can replace subscribe with block, but pay attention that this is a blocking operation:

Integer result = mono.map(App2::doSomething).block();