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-clientcloud:compatibility-verifier:enabled: false
eureka:client:service-url:defaultZone: http://localhost:8761/eureka/instance:hostname: localhost
server:servlet:context-path: /eureka-clientport: 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 {@Beanpublic 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_routeuri: http://localhost:8080predicates:- 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

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

Spring Cloud Gateway Server MVC :: Spring Cloud Gateway