之前你如果要用spring cloud gateway ，就必须是webflux 的，也就是必须是异步响应式编程。不能和spring mvc 一起使用。现在spring cloud 新出了一个可以不用webflux的gateway。

具体使用mvc的gateway步骤如下

普通的Eureka Client的项目

如果你只是想测试一下gateway mvc，可以建一个普通的spring boot项目，然后写一个/test rest api就可以了。

application.yml

spring:
  application:
    name: eureka-client
  cloud:
    compatibility-verifier:
      enabled: false
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/
  instance:
    hostname: localhost
server:
  servlet:
    context-path: /eureka-client
  port: 8080

TestController.java

@RestController
public class TestController {

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    public String test() {
        return "test";
    }
}

EurekaClientApplication.java

@SpringBootApplication
@EnableDiscoveryClient
public class EurekaClientApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaClientApplication.class, args);
    }
}

访问http://localhost:8080/eureka-client/test

Gateway MVC 的项目

在pom.xml加spring-cloud-starter-gateway-mvc 

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <java.version>17</java.version>
        <spring-cloud.version>2023.0.0</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway-mvc</artifactId>
        </dependency>

    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

application.yml

spring:
  application:
    name: gateway-mvc
server:
  port: 8088

RouteConfiguration.java

package com.example.gateway;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.function.RouterFunction;
import org.springframework.web.servlet.function.ServerResponse;

import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;

@Configuration
public class RouteConfiguration {

    @Bean
    public RouterFunction<ServerResponse> getRoute() {
        return route("simple_route").GET("/eureka-client/**", http("http://localhost:8080")).build();
    }
}

或者用配置文件的方式.application.yml

spring:
  cloud:
    gateway:
      mvc:
        routes:
          - id: simple_route
            uri: http://localhost:8080
            predicates:
              - Path=/eureka-client/**

GatewayApplication.java

@SpringBootApplication
public class GatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(GatewayApplication.class, args);
    }

}

访问http://localhost:8080/eureka-client/test

如果你不想hardcode 你的hostname和端口，也可以用Eureka 的方式来获取hostname和端口号

    @Bean
    public RouterFunction<ServerResponse> gatewayRouterFunctionsAddReqHeader() {
        return route("api_route")
                .GET("/eureka-client/**", http())
                .filter(lb("EUREKA-CLIENT"))
                .build();
    }

Spring Cloud Gateway Server MVC :: Spring Cloud Gateway