토비의 봄 TV 14회 스프링 리액티브 프로그래밍 (10) Flux의 특징과 활용방법

(시청일 : 20180114)

- https://www.youtube.com/watch?v=bc4wTgA_2Xk

■ 예제 1

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Mono;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<Event> hello(@PathVariable long id) {

        return Mono.just(new Event(id, "event" + id));

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/event/123

{"id":123,"value":"event123"}

■ 예제 2

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<Event> hello(@PathVariable long id) {

        return Mono.just(new Event(id, "event" + id));

    }

    @GetMapping("/events")

    Flux<Event> events() {

        return Flux.just(new Event(1L, "event1"), new Event(2L, "event2"));

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

[{"id":1,"value":"event1"},{"id":2,"value":"event2"}]

■ 예제 3

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.util.Arrays;

import java.util.List;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping("/events")

    Flux<Event> events() {

        return Flux.just(new Event(1L, "event1"), new Event(2L, "event2"));

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/event/1

[{"id":1,"value":"event1"},{"id":2,"value":"event2"}]

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

[{"id":1,"value":"event1"},{"id":2,"value":"event2"}]

■ 예제 3

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.util.Arrays;

import java.util.List;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Flux.fromIterable(list);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1,"value":"event1"}

data:{"id":2,"value":"event2"}

<Flux>

<Flux.fromIterable()>

■ 예제 4

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.time.Duration;

import java.util.Arrays;

import java.util.List;

import java.util.stream.Stream;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        return Flux

                .fromStream(Stream.generate(() -> new Event(System.currentTimeMillis(), "value")))

                .delayElements(Duration.ofSeconds(1))

                .take(10);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1516531806083,"value":"value"}

data:{"id":1516531806192,"value":"value"}

data:{"id":1516531806194,"value":"value"}

data:{"id":1516531806195,"value":"value"}

data:{"id":1516531806210,"value":"value"}

data:{"id":1516531806213,"value":"value"}

data:{"id":1516531806215,"value":"value"}

data:{"id":1516531806216,"value":"value"}

data:{"id":1516531806217,"value":"value"}

data:{"id":1516531806219,"value":"value"}

<Flux.take()>

■ 예제 5

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.time.Duration;

import java.util.Arrays;

import java.util.List;

import java.util.stream.Stream;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        return Flux

                .<Event>generate(sink -> sink.next(new Event(System.currentTimeMillis(), "value")))

                .delayElements(Duration.ofSeconds(1))

                .take(10);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1516533395000,"value":"value"}

data:{"id":1516533396018,"value":"value"}

data:{"id":1516533397019,"value":"value"}

data:{"id":1516533398021,"value":"value"}

data:{"id":1516533399023,"value":"value"}

data:{"id":1516533400023,"value":"value"}

data:{"id":1516533401024,"value":"value"}

data:{"id":1516533402025,"value":"value"}

data:{"id":1516533403026,"value":"value"}

data:{"id":1516533404027,"value":"value"}

■ 예제 6

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.time.Duration;

import java.util.Arrays;

import java.util.List;

import java.util.stream.Stream;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        return Flux

                .<Event, Long>generate(()->1L, (id, sink) -> {

                    sink.next(new Event(id, "value" + id));

                    return id+1;

                })

                .delayElements(Duration.ofSeconds(1))

                .take(10);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1,"value":"value1"}

data:{"id":2,"value":"value2"}

data:{"id":3,"value":"value3"}

data:{"id":4,"value":"value4"}

data:{"id":5,"value":"value5"}

data:{"id":6,"value":"value6"}

data:{"id":7,"value":"value7"}

data:{"id":8,"value":"value8"}

data:{"id":9,"value":"value9"}

data:{"id":10,"value":"value10"}

■ 예제 7

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.time.Duration;

import java.util.Arrays;

import java.util.List;

import java.util.stream.Stream;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        Flux<Event> es = Flux

                .<Event, Long>generate(()->1L, (id, sink) -> {

                    sink.next(new Event(id, "value" + id));

                    return id+1;

                });

        Flux<Long> interval = Flux.interval(Duration.ofSeconds(1));

        return Flux.zip(es, interval).map(tu->tu.getT1()).take(10);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1,"value":"value1"}

data:{"id":2,"value":"value2"}

data:{"id":3,"value":"value3"}

data:{"id":4,"value":"value4"}

data:{"id":5,"value":"value5"}

data:{"id":6,"value":"value6"}

data:{"id":7,"value":"value7"}

data:{"id":8,"value":"value8"}

data:{"id":9,"value":"value9"}

data:{"id":10,"value":"value10"}

■ 예제 8

package toby.tobytv014;

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.extern.slf4j.Slf4j;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RestController;

import reactor.core.publisher.Flux;

import reactor.core.publisher.Mono;

import java.time.Duration;

import java.util.Arrays;

import java.util.List;

import java.util.stream.Stream;

@SpringBootApplication

@Slf4j

@RestController

public class Tobytv014Application {

    @GetMapping("/event/{id}")

    Mono<List<Event>> hello(@PathVariable long id) {

        List<Event> list = Arrays.asList(new Event(1L, "event1"), new Event(2L, "event2"));

        return Mono.just(list);

    }

    @GetMapping(value="/events", produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    Flux<Event> events() {

        Flux<String> es = Flux.generate(sink -> sink.next("Value"));

        Flux<Long> interval = Flux.interval(Duration.ofSeconds(1));

        return Flux.zip(es, interval).map(tu -> new Event(tu.getT2()+1, tu.getT1())).take(10);

    }

    public static void main(String[] args) {

        SpringApplication.run(Tobytv014Application.class, args);

    }

    @Data    @AllArgsConstructor

    public static class Event {

        long id;

        String value;

    }

}

<Terminal>

C:\Users\Soohyeon\Desktop\curl_7_53_1_openssl_nghttp2_x64>curl localhost:8080/events

data:{"id":1,"value":"Value"}

data:{"id":2,"value":"Value"}

data:{"id":3,"value":"Value"}

data:{"id":4,"value":"Value"}

data:{"id":5,"value":"Value"}

data:{"id":6,"value":"Value"}

data:{"id":7,"value":"Value"}

data:{"id":8,"value":"Value"}

data:{"id":9,"value":"Value"}

data:{"id":10,"value":"Value"}

<Flux.generate()>

<Flux.interval()>

<Flux.zip()>