リアクティブ Web アプリケーション

import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/users")
public class MyRestController {

	private final UserRepository userRepository;

	private final CustomerRepository customerRepository;

	public MyRestController(UserRepository userRepository, CustomerRepository customerRepository) {
		this.userRepository = userRepository;
		this.customerRepository = customerRepository;
	}

	@GetMapping("/{userId}")
	public Mono<User> getUser(@PathVariable Long userId) {
		return this.userRepository.findById(userId);
	}

	@GetMapping("/{userId}/customers")
	public Flux<Customer> getUserCustomers(@PathVariable Long userId) {
		return this.userRepository.findById(userId).flatMapMany(this.customerRepository::findByUser);
	}

	@DeleteMapping("/{userId}")
	public Mono<Void> deleteUser(@PathVariable Long userId) {
		return this.userRepository.deleteById(userId);
	}

}

import org.springframework.web.bind.annotation.DeleteMapping
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.PathVariable
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController
import reactor.core.publisher.Flux
import reactor.core.publisher.Mono

@RestController
@RequestMapping("/users")
class MyRestController(private val userRepository: UserRepository, private val customerRepository: CustomerRepository) {

	@GetMapping("/{userId}")
	fun getUser(@PathVariable userId: Long): Mono<User?> {
		return userRepository.findById(userId)
	}

	@GetMapping("/{userId}/customers")
	fun getUserCustomers(@PathVariable userId: Long): Flux<Customer> {
		return userRepository.findById(userId).flatMapMany { user: User? ->
			customerRepository.findByUser(user)
		}
	}

	@DeleteMapping("/{userId}")
	fun deleteUser(@PathVariable userId: Long): Mono<Void> {
		return userRepository.deleteById(userId)
	}

}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.server.RequestPredicate;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerResponse;

import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
import static org.springframework.web.reactive.function.server.RouterFunctions.route;

@Configuration(proxyBeanMethods = false)
public class MyRoutingConfiguration {

	private static final RequestPredicate ACCEPT_JSON = accept(MediaType.APPLICATION_JSON);

	@Bean
	public RouterFunction<ServerResponse> monoRouterFunction(MyUserHandler userHandler) {
		return route()
				.GET("/{user}", ACCEPT_JSON, userHandler::getUser)
				.GET("/{user}/customers", ACCEPT_JSON, userHandler::getUserCustomers)
				.DELETE("/{user}", ACCEPT_JSON, userHandler::deleteUser)
				.build();
	}

}

import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.http.MediaType
import org.springframework.web.reactive.function.server.RequestPredicates.DELETE
import org.springframework.web.reactive.function.server.RequestPredicates.GET
import org.springframework.web.reactive.function.server.RequestPredicates.accept
import org.springframework.web.reactive.function.server.RouterFunction
import org.springframework.web.reactive.function.server.RouterFunctions
import org.springframework.web.reactive.function.server.ServerResponse

@Configuration(proxyBeanMethods = false)
class MyRoutingConfiguration {

	@Bean
	fun monoRouterFunction(userHandler: MyUserHandler): RouterFunction<ServerResponse> {
		return RouterFunctions.route(
			GET("/{user}").and(ACCEPT_JSON), userHandler::getUser).andRoute(
			GET("/{user}/customers").and(ACCEPT_JSON), userHandler::getUserCustomers).andRoute(
			DELETE("/{user}").and(ACCEPT_JSON), userHandler::deleteUser)
	}

	companion object {
		private val ACCEPT_JSON = accept(MediaType.APPLICATION_JSON)
	}

}

import reactor.core.publisher.Mono;

import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;

@Component
public class MyUserHandler {

	public Mono<ServerResponse> getUser(ServerRequest request) {
		...
	}

	public Mono<ServerResponse> getUserCustomers(ServerRequest request) {
		...
	}

	public Mono<ServerResponse> deleteUser(ServerRequest request) {
		...
	}

}

import org.springframework.stereotype.Component
import org.springframework.web.reactive.function.server.ServerRequest
import org.springframework.web.reactive.function.server.ServerResponse
import reactor.core.publisher.Mono

@Component
class MyUserHandler {

	fun getUser(request: ServerRequest?): Mono<ServerResponse> {
		...
	}

	fun getUserCustomers(request: ServerRequest?): Mono<ServerResponse> {
		...
	}

	fun deleteUser(request: ServerRequest?): Mono<ServerResponse> {
		...
	}

}