ssouris

fun view(serverRequest: ServerRequest) =
 serverRequest.queryParam("id").map { ownersRepository.findById(it) }
  .orElse(Mono.empty<Owner>())// still Java8 Optional here
  .and({ (id) -> petRepository.findAllByOwner(id).collectList() })
  // destructuring of Tuple2 possible due to reactor-extensions must 
  // import reactor.util.function.component1
  // import reactor.util.function.component2
  .flatMap { (owner, pets) -> 
   val model = mapOf<String, Any>(

ssouris

fun edit(serverRequest: ServerRequest) = serverRequest.body(BodyExtractors.toFormData())
  .flatMap {
      val formData = it.toSingleValueMap()
      petRepository.save(
        Pet(id = formData["id"]!!,
            name = formData["name"]!!,
            birthDate = formData["birthDate"]!!.toDate(),
            owner = formData["ownerId"]!!,
            type = formData["type"]!!))

ssouris

@Bean
fun petClinicRouter(ownersHandler: OwnersHandler,
                    ...
                    visitHandler: VisitHandler) =
  router {
    "/owners".nest {
      GET("/", ownersHandler::goToOwnersIndex)
      "/add".nest {
        GET("/", ownersHandler::goToAddPage)

ssouris

@Repository 
interface OwnersRepository : ReactiveMongoRepository<Owner, String>

@Repository 
interface VisitRepository : ReactiveMongoRepository<Visit, String>

ssouris

data class Owner(val firstName: String, val lastName: String)

val loremIpsum = Owner(firstName="Lorem", lastName="Ipsum") 
// destructuring
val (firstName, lastName) = loremIpsum

ssouris

@Bean
public Function<String, String> uppercase() {
  return value -> value.toUpperCase();
}

@Bean
public Function<Flux<String>, Flux<String>> lowercase() {
  return flux -> flux.map(value -> value.toLowerCase());
}

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interface PersonRepository extends ReactiveCrudRepository<Person, String> {

  Flux<Person> findAllByName(String name);

  Observable<Person> findByName(String name);

  @Tailable
  Flux<Person> findBy();
  
}

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// Java functional registration
public RouterFunction<ServerResponse> routingFunction(PersonHandler handler) {	
  return nest(
    path("/person"), nest(
      accept(APPLICATION_JSON),
        route(GET("/{id}"), handler::getPerson)
        .andRoute(method(HttpMethod.GET), handler::listPeople))
        .andRoute(POST("/").and(contentType(APPLICATION_JSON)), handler::createPerson));
}

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@RestController
class PersonController(val personRepository: PersonRepository) {
    
    @GetMapping("/people")
    fun findPeople() = personRepository.findAll()

    @GetMapping("/people/{personId}")
    fun findPeople(@PathVariable personId:String) = personRepository.findOne(personId)
    
}

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# Run Kafka, Zookeeper, Kafka manager, MongoDB
docker-compose up -d

# ild Producer/Consumer
mvn -f producer/pom.xml clean package
mvn -f consumer/pom.xml clean package
#Run Producer
java -jar producer/target/producer.jar
#Run Consumer