SpringCloudGateway基本操作-WebFlux

Create a WebFlux Handler

In the Spring Reactive approach, we use a handler to handle the request and create a response, as shown in the following example:

//src/main/java/hello/GreetingHandler.java
package hello;

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

import reactor.core.publisher.Mono;

@Component
public class GreetingHandler {

  public Mono<ServerResponse> hello(ServerRequest request) {
    return ServerResponse.ok().contentType(MediaType.TEXT_PLAIN)
      .body(BodyInserters.fromValue("Hello, Spring!"));
  }
}

This simple reactive class always returns “Hello, Spring!” It could return many other things, including a stream of items from a database, a stream of items that were generated by calculations, and so on. Note the reactive code: a Mono object that holds a ServerResponse body.

Create a Router

In this application, we use a router to handle the only route we expose (“/hello”), as shown in the following example:

//src/main/java/hello/GreetingRouter.java
package hello;

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;
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
public class GreetingRouter {

  @Bean
  public RouterFunction<ServerResponse> route(GreetingHandler greetingHandler) {

    return RouterFunctions
      .route(RequestPredicates.GET("/hello").and(RequestPredicates.accept(MediaType.TEXT_PLAIN)), greetingHandler::hello);
  }
}

The router listens for traffic on the /hello path and returns the value provided by our reactive handler class.