How to prevent the start of the embedded netty server using spring-boot-starter-webflux?

Question

I want to establish a connection between the client and server applications using the new reactive extension webflux Springs.

For dependency management I use gradle . My build.gradle file on the server as well as on the client side basically:

buildscript {
    repositories {
        mavenCentral()
        maven { url "https://repo.spring.io/snapshot" }
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.0.0.BUILD-SNAPSHOT")
    }
}

repositories {
    mavenCentral()
    maven { url "https://repo.spring.io/snapshot" }
}

apply plugin: 'java'
apply plugin: 'org.springframework.boot'
apply plugin: "io.spring.dependency-management" 

dependencies {
    compile("org.springframework.boot:spring-boot-starter-webflux")
}

(It should be noted that 2.0.0.BUILD- SNAPSHOT is a moving target, and the problem at hand may simply disappear in one day due to changes within dependencies)

When I run the application on the server side, everything starts well, including starting the built-in netty server.

netty-, "java.net.BindException: Address ", - , netty-.

: netty ?

Spring -Boot Documentation Spring , Web Spring.

setWebEnvironment (false). :

@SpringBootApplication(scanBasePackages = { "com.tatics.flux.main" })
public class Client {
    public static void main(String[] args) throws Exception {
        SpringApplication app = new SpringApplication(Client.class);
        app.setWebEnvironment(false);
        app.run(Client.class, args);

        WebClient webClient = WebClient.create();

        Mono<String> result = webClient
                .post()
                .uri("http://localhost:8080/fluxService")

                // This does not work any more: .body("Hallo")
                // and must be replaced by:
                .body(BodyInserters.fromObject("Hallo"))

                .accept(MediaType.TEXT_PLAIN)
                .exchange()
                .flatMap(response -> response.bodyToMono(String.class));
    }
}

, netty . , setWebEnvironment (false) .

, netty, webflux.

:

=========================
AUTO-CONFIGURATION REPORT
=========================

Positive matches:
-----------------
...

ReactiveWebServerAutoConfiguration matched:
  - found ReactiveWebApplicationContext (OnWebApplicationCondition)

ReactiveWebServerAutoConfiguration#defaultReactiveWebServerCustomizer matched:
  - @ConditionalOnMissingBean (types: org.springframework.boot.autoconfigure.web.reactive.DefaultReactiveWebServerCustomizer; SearchStrategy: all) did not find any beans (OnBeanCondition)

ReactiveWebServerConfiguration.ReactorNettyAutoConfiguration matched:
  - @ConditionalOnClass found required class 'reactor.ipc.netty.http.server.HttpServer'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)
  - @ConditionalOnMissingBean (types: org.springframework.boot.web.reactive.server.ReactiveWebServerFactory; SearchStrategy: all) did not find any beans (OnBeanCondition)

ReactorCoreAutoConfiguration matched:
  - @ConditionalOnClass found required classes 'reactor.core.publisher.Mono', 'reactor.core.publisher.Flux'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)

...

Negative matches:
-----------------
...
ReactiveWebServerConfiguration.JettyAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'org.eclipse.jetty.server.Server' (OnClassCondition)

ReactiveWebServerConfiguration.TomcatAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'org.apache.catalina.startup.Tomcat' (OnClassCondition)

ReactiveWebServerConfiguration.UndertowAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'io.undertow.Undertow' (OnClassCondition)

...

ReactiveWebServerConfiguration.JettyAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'org.eclipse.jetty.server.Server' (OnClassCondition)

ReactiveWebServerConfiguration.TomcatAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'org.apache.catalina.startup.Tomcat' (OnClassCondition)

ReactiveWebServerConfiguration.UndertowAutoConfiguration:
  Did not match:
     - @ConditionalOnClass did not find required class 'io.undertow.Undertow' (OnClassCondition)

Answer 1

, SpringApplication, - , , run(Object primarySource, String... args).

:

@SpringBootApplication
public class Client {

    public static void main(String[] args) throws Exception {
        SpringApplication app = new SpringApplication(Client.class);
        app.setWebApplicationType(WebApplicationType.NONE);
        app.run(args);
    }

    @Bean
    public CommandLineRunner myCommandLineRunner() {
      return args -> {
        // we have to block here, since command line runners don't
        // consume reactive types and simply return after the execution
        String result = WebClient.create("http://localhost:8080")
                .post()
                .uri("/fluxService")
                .body("Hallo")
                .accept(MediaType.TEXT_PLAIN)
                .retrieve()
                .bodyToMono(String.class)
                .block();
        // print the result?
      };
    }
}

, --debug , , .

Answer 2

@Brian_Clozel:

Netty ( ), application.yml:

spring.main.web-application-type: none

application.properties:

spring.main.web-application-type=none