If you have Spring WebFlux on your classpath, you can also choose to use WebClient to call remote REST services; compared to RestTemplate, this client has more a functional feel to it and is fully reactive. You can create your own client instance with the builder WebClient.create(), which already provides a good out-of-the-box experience. See the relevant section on WebClient.

Spring Boot will create and pre-configure such a builder for you; for example, client HTTP codecs will be configured just like the server ones (see WebFlux HTTP codecs auto-configuration).

Here’s a typical example:

@Service
public class MyService {

    private final WebClient webClient;

    public MyBean(WebClient.Builder webClientBuilder) {
        this.webClient = webClientBuilder.baseUrl("http://example.org").build();
    }

    public Mono<Details> someRestCall(String name) {
        return this.webClient.get().url("/{name}/details", name)
                        .retrieve().bodyToMono(Details.class);
    }

}