SpringBoot 3.0.0无法识别Eureka服务与客户端问题咨询

在SpringBoot 3.0.0环境下，Eureka Server与Client无法互相识别，但切换到2.7.4版本后可正常运行，以下是版本间的关键变更及修复方案，附原代码实现：

Api-Gateway（Eureka Server） #

启动类代码 #

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

application.properties配置 #

spring.application.name = api-gateway
server.port = 8761
eureka.client.register-with-eureka = false
eureka.client.fetch-registry = false
eureka.instance.hostname=localhost
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

路由模块（Gateway + Eureka Client） #

启动类代码 #

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

application.properties配置 #

server.port=8080
spring.application.name=routing
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
eureka.instance.hostname=localhost
spring.cloud.gateway.discovery.locator.enabled=true

#spring.main.web-application-type=reactive
spring.cloud.gateway.enabled=true
spring.cloud.gateway.routes[0].id=user
spring.cloud.gateway.routes[0].uri=lb://USER
spring.cloud.gateway.routes[0].predicates=Path=/user/**

spring.cloud.gateway.routes[1].id=testes
spring.cloud.gateway.routes[1].uri=lb://TESTES
spring.cloud.gateway.routes[1].predicates=Path=/testes/**

spring.cloud.gateway.routes[2].id=user-create
spring.cloud.gateway.routes[2].uri=lb://USER-CREATE
spring.cloud.gateway.routes[2].predicates=Path=/user-create/**

spring.cloud.gateway.routes[3].id=category-product
spring.cloud.gateway.routes[3].uri=lb://CATEGORY-PRODUCT
spring.cloud.gateway.routes[3].predicates=Path=/category-product/**

Category-Product模块（Eureka Client） #

启动类代码 #

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

控制器代码 #

@RestController
@RequestMapping("/category-product")
public class CategoryProductContriller {
  @GetMapping("/item")
  public String itens()
  {
    return "Testar";
  }
}

application.properties配置 #

server.port = 8001
spring.application.name = category-product
eureka.client.serviceUrl.defaultZone = http://localhost:8761/eureka
eureka.instance.hostname=localhost

版本间关键变更及修复方案 #

1. 依赖版本适配 #

SpringBoot 3.0.x对应的Spring Cloud版本为2022.0.x（Kilburn），该版本基于Jakarta EE 9，而适配SpringBoot 2.x的旧版Eureka依赖Java EE（javax包），会导致类加载异常。需确保引入适配Jakarta的Eureka依赖：

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>2022.0.4</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<!-- Eureka Server -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

<!-- Eureka Client -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<!-- Spring Cloud Gateway -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

2. 配置属性格式修正 #

SpringBoot 3.0对配置属性绑定更严格，Eureka Client的配置前缀从驼峰式eureka.client.serviceUrl.defaultZone改为短横线分隔的eureka.client.service-url.defaultZone，同时注意URL末尾的/需统一添加，避免解析错误：

# 修正后的配置
eureka.client.service-url.defaultZone=http://localhost:8761/eureka/

3. 恢复Gateway的Reactive模式 #

Spring Cloud Gateway基于WebFlux实现，必须运行在Reactive环境下，取消注释路由模块配置中的spring.main.web-application-type=reactive：

spring.main.web-application-type=reactive

验证步骤 #

1. 启动Api-Gateway（Eureka Server），访问http://localhost:8761确认控制台正常显示；
2. 启动Category-Product模块，查看Eureka控制台是否成功注册该服务；
3. 启动路由模块，访问http://localhost:8080/category-product/item验证路由是否生效。

内容的提问来源于stack exchange，提问作者Rafael Souza