项目结构

microservice-example/
├── gateway-app/         # API网关服务 (8080)
├── member-service/      # 会员服务 (8081)
├── purchase-service/    # 采购服务 (8082)
└── pom.xml              # 父级POM文件

依赖管理

<properties>
    <java.version>17</java.version>
    <spring-boot.version>3.2.0</spring-boot.version>
    <spring-cloud.version>2023.0.0</spring-cloud.version>
    <spring-cloud-alibaba.version>2023.0.0.0</spring-cloud-alibaba.version>
</properties>

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

服务注册中心配置

Nacos安装

wget https://repo.alibaba.com/nacos-server/2.3.0/nacos-server-2.3.0.zip
unzip nacos-server-2.3.0.zip
cd nacos/bin
./startup.sh -m standalone

服务注册

# member-service配置
spring:
  application:
    name: member-service
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
        namespace: development

server:
  port: 8081

启动类

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

API网关实现

网关依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

路由配置

spring:
  cloud:
    gateway:
      routes:
        - id: member-route
          uri: lb://member-service
          predicates:
            - Path=/v1/member/**
          filters:
            - StripPrefix=1
        - id: purchase-route
          uri: lb://purchase-service
          predicates:
            - Path=/v1/purchase/**
      globalcors:
        cors-configurations:
          '[/**]':
            allowedMethods: [GET, POST]

服务调用与负载均衡

@RestController
@RequestMapping("/member")
public class MemberController {

    private final PurchaseClient purchaseClient;

    @GetMapping("/{id}/orders")
    public List<PurchaseOrder> getOrders(@PathVariable Long id) {
        return purchaseClient.fetchOrders(id);
    }
}

// Feign客户端
@FeignClient("purchase-service")
public interface PurchaseClient {
    @GetMapping("/orders/{memberId}")
    List<PurchaseOrder> fetchOrders(@PathVariable Long memberId);
}

负载均衡策略

@Configuration
public class BalancerConfig {
    @Bean
    public ReactorLoadBalancer<ServiceInstance> weightedBalancer(
            Environment env, LoadBalancerClientFactory factory) {
        String serviceName = env.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
        return new RoundRobinLoadBalancer(
            factory.getLazyProvider(serviceName, ServiceInstanceListSupplier.class),
            serviceName
        );
    }
}

系统启动流程

1. 启动Nacos服务(8848端口)
2. 启动member-service(8081端口)
3. 启动purchase-service(8082端口)
4. 启动gateway-app(8080端口)
5. 访问 http://localhost:8080/v1/member/1001/orders

常见问题处理

• 服务未注册：检查Nacos配置地址和命名空间
• 网关路由失败：验证下游服务注册状态
• 负载异常：确认lb://协议前缀配置正确