Binding using Reactive Frameworks

From a developer perspective however, you can generally just work with Plain Old Java Objects (POJOs) and can optionally use a Reactive framework such as RxJava or Reactor. The following is an example of a controller that reads and saves an incoming POJO in a non-blocking way from JSON:

Using RxJava 2 to Read the JSON

@Controller("/people")
public class PersonController {
    Map<String, Person> inMemoryDatastore = new ConcurrentHashMap<>();
    @Post("/saveReactive")
    public Single<HttpResponse<Person>> save(@Body Single<Person> person) { (1)
        return person.map(p -> {
                    inMemoryDatastore.put(p.getFirstName(), p); (2)
                    return HttpResponse.created(p); (3)
                }
        );
    }
}

Using RxJava 2 to Read the JSON

@Controller("/people")
class PersonController {
    ConcurrentHashMap<String, Person> inMemoryDatastore = [:]
    @Post("/saveReactive")
    Single<HttpResponse<Person>> save(@Body Single<Person> person) { (1)
        person.map({ p ->
            inMemoryDatastore.put(p.getFirstName(), p) (2)
            HttpResponse.created(p) (3)
        })
    }
}

Using RxJava 2 to Read the JSON

@Controller("/people")
class PersonController {
    internal var inMemoryDatastore: MutableMap<String, Person> = ConcurrentHashMap()
    @Post("/saveReactive")
    fun save(@Body person: Single<Person>): Single<HttpResponse<Person>> { (1)
        return person.map { p ->
            inMemoryDatastore[p.firstName] = p (2)
            HttpResponse.created(p) (3)
        }
    }
}

Using CURL from the command line you can POST JSON to the /people URI for the server to receive it:

Using CURL to Post JSON

$ curl -X POST localhost:8080/people -d '{"firstName":"Fred","lastName":"Flintstone","age":45}'