# 下载 Nacos
wget https://github.com/alibaba/nacos/releases/download/2.2.0/nacos-server-2.2.0.tar.gz

# 解压并启动
tar -xzf nacos-server-2.2.0.tar.gz
cd nacos/bin
sh startup.sh -m standalone

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

spring:
  application:
    name: user-service
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
        namespace: dev
        group: DEFAULT_GROUP

spring:
  cloud:
    nacos:
      config:
        server-addr: localhost:8848
        file-extension: yaml
        namespace: dev
        group: DEFAULT_GROUP
        shared-configs:
          - data-id: common-config.yaml
            group: DEFAULT_GROUP
            refresh: true

@RestController
@RefreshScope
public class ConfigController {
    @Value("${app.name:default}")
    private String appName;

    @GetMapping("/config")
    public String getConfig() {
        return appName;
    }
}

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>

spring:
  cloud:
    sentinel:
      transport:
        dashboard: localhost:8080
        port: 8719
      datasource:
        flow:
          nacos:
            server-addr: localhost:8848
            dataId: ${spring.application.name}-flow-rules
            groupId: SENTINEL_GROUP
            rule-type: flow

@Service
public class UserService {
    @SentinelResource(value = "getUser", blockHandler = "getUserBlockHandler")
    public User getUser(Long id) {
        return userRepository.findById(id)
            .orElseThrow(() -> new UserNotFoundException(id));
    }

    public User getUserBlockHandler(Long id, BlockException ex) {
        return new User(); // 降级处理
    }
}

@SentinelResource(
    value = "getUser",
    fallback = "getUserFallback",
    blockHandler = "getUserBlockHandler"
)
public User getUser(Long id) {
    // 业务逻辑
}

public User getUserFallback(Long id, Throwable ex) {
    // 降级处理
    return new User();
}

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-rocketmq</artifactId>
</dependency>

spring:
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: localhost:9876
        bindings:
          output:
            producer:
              group: user-service-group

@Service
public class UserService {
    private final RocketMQTemplate rocketMQTemplate;

    public UserService(RocketMQTemplate rocketMQTemplate) {
        this.rocketMQTemplate = rocketMQTemplate;
    }

    public void sendUserCreatedEvent(User user) {
        rocketMQTemplate.convertAndSend("user-topic", user);
    }
}

@Component
@RocketMQMessageListener(
    topic = "user-topic",
    consumerGroup = "user-consumer-group"
)
public class UserEventListener implements RocketMQListener<User> {
    @Override
    public void onMessage(User user) {
        // 处理消息
        System.out.println("Received user: " + user.getName());
    }
}

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
</dependency>

spring:
  cloud:
    alibaba:
      seata:
        tx-service-group: my-tx-group
        enabled: true

seata:
  enabled: true
  application-id: ${spring.application.name}
  tx-service-group: my-tx-group
  config:
    type: nacos
    nacos:
      server-addr: localhost:8848
      namespace: ""
      group: SEATA_GROUP
  registry:
    type: nacos
    nacos:
      server-addr: localhost:8848
      namespace: ""
      group: SEATA_GROUP

@Service
public class OrderService {
    @GlobalTransactional
    public void createOrder(Order order) {
        // 1. 创建订单
        orderRepository.save(order);

        // 2. 扣减库存
        productService.reduceStock(order.getProductId(), order.getQuantity());

        // 3. 扣减余额
        accountService.deductBalance(order.getUserId(), order.getAmount());
    }
}

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-dubbo</artifactId>
</dependency>

spring:
  cloud:
    dubbo:
      application:
        name: user-service
      registry:
        address: nacos://localhost:8848
      protocol:
        name: dubbo
        port: 20880

@Service
@org.apache.dubbo.config.annotation.Service
public class UserServiceImpl implements UserService {
    public User getUser(Long id) {
        return userRepository.findById(id).orElseThrow();
    }
}

@Service
public class OrderService {
    @org.apache.dubbo.config.annotation.Reference
    private UserService userService;

    public Order createOrder(Long userId, Order order) {
        User user = userService.getUser(userId);
        // 创建订单逻辑
        return order;
    }
}

microservices/
├── nacos-server/           # Nacos 服务
├── gateway/                # API 网关
├── user-service/           # 用户服务
├── order-service/          # 订单服务
└── product-service/        # 商品服务

# Nacos 配置中心
spring:
  cloud:
    nacos:
      config:
        server-addr: localhost:8848
        file-extension: yaml
        namespace: ${spring.profiles.active}
        group: DEFAULT_GROUP
        extension-configs:
          - data-id: common-datasource.yaml
            group: DEFAULT_GROUP
            refresh: true
          - data-id: common-redis.yaml
            group: DEFAULT_GROUP
            refresh: true

<!-- Nacos Discovery -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>

<!-- Nacos Config -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>

<!-- Sentinel -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>

<!-- RocketMQ -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-rocketmq</artifactId>
</dependency>

<!-- Seata -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
</dependency>