使用feign客户端时，Spring服务返回内容为空

@RestController
public class ProviderController {
    @GetMapping("/data")
    public Map<String, String> getData() {
        Map<String, String> data = new HashMap<>();
        data.put("message", "Hello from provider!");
        return data;
    }
}

@FeignClient(name = "service-provider")
public interface ServiceProviderClient {
    @GetMapping("/data")
    Map<String, String> getData();
}

@Service
public class ConsumerService {
    private final ServiceProviderClient serviceProviderClient;

    @Autowired
    public ConsumerService(ServiceProviderClient serviceProviderClient) {
        this.serviceProviderClient = serviceProviderClient;
    }

    public void consumeData() {
        Map<String, String> data = serviceProviderClient.getData();
        if (data.isEmpty()) {
            System.out.println("Received empty data.");
        } else {
            System.out.println("Received data: " + data);
        }
    }
}