Exchange

The exchangeToMono() and exchangeToFlux() methods (or awaitExchange { } and exchangeToFlow { } in Kotlin) are useful for more advanced cases that require more control, such as to decode the response differently depending on the response status:

  • Java

  • Kotlin

Mono<Person> entityMono = client.get()
		.uri("/persons/1")
		.accept(MediaType.APPLICATION_JSON)
		.exchangeToMono(response -> {
			if (response.statusCode().equals(HttpStatus.OK)) {
				return response.bodyToMono(Person.class);
			}
			else {
				// Turn to error
				return response.createError();
			}
		});
val entity = client.get()
  .uri("/persons/1")
  .accept(MediaType.APPLICATION_JSON)
  .awaitExchange {
		if (response.statusCode() == HttpStatus.OK) {
			 return response.awaitBody<Person>()
		}
		else {
			 throw response.createExceptionAndAwait()
		}
  }

When using the above, after the returned Mono or Flux completes, the response body is checked and if not consumed it is released to prevent memory and connection leaks. Therefore the response cannot be decoded further downstream. It is up to the provided function to declare how to decode the response if needed.