首先，确保项目中包含必要的依赖项。如果在阿里云仓库找不到相关依赖，请访问阿里云Maven仓库搜索页面查找。

配置文件中需启用特定设置以支持负载均衡功能：

接下来，创建一个加载类，并利用@LoadBalancerClient注解来指定无需额外的配置类声明：

返回值可以通过自定义类来处理，例如通过继承ReactorLoadBalancer<ServiceInstance>接口来实现具体的负载均衡逻辑。

以下是配置类的示例代码：

public class CustomBalancerSetup {

    @Bean
    ReactorLoadBalancer<ServiceInstance> customBalancer(Environment env,
                                                        LoadBalancerClientFactory lbFactory) {
        String svcName = env.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
        return new CustomBalancer(lbFactory.getLazyProvider(svcName, ServiceInstanceListSupplier.class), svcName);
    }
}

自定义的轮询算法可以参考如下实现：

public class CustomBalancer implements ReactorServiceInstanceLoadBalancer {

    private static final Log logger = LogFactory.getLog(CustomBalancer.class);

    final AtomicInteger index;

    final String serviceName;

    private static int callCount = 0;

    private static Response<ServiceInstance> cachedResponse = null;

    ObjectProvider<ServiceInstanceListSupplier> serviceSupplierProvider;

    public CustomBalancer(ObjectProvider<ServiceInstanceListSupplier> provider, String svcName) {
        this(provider, svcName, new Random().nextInt(1000));
    }

    public CustomBalancer(ObjectProvider<ServiceInstanceListSupplier> provider, String svcName, int startPos) {
        this.serviceName = svcName;
        this.serviceSupplierProvider = provider;
        this.index = new AtomicInteger(startPos);
    }

    @Override
    public Mono<Response<ServiceInstance>> choose(Request request) {
        ServiceInstanceListSupplier supplier = serviceSupplierProvider.getIfAvailable(NoopServiceInstanceListSupplier::new);
        return supplier.get(request).next()
                .map(serviceInstances -> handleResponse(supplier, serviceInstances));
    }

    private Response<ServiceInstance> handleResponse(ServiceInstanceListSupplier supplier,
                                                     List<ServiceInstance> instances) {
        if (cachedResponse != null && callCount <= 4) {
            callCount++;
            return cachedResponse;
        }

        Response<ServiceInstance> response = selectInstance(instances);
        if (supplier instanceof SelectedInstanceCallback && response.hasServer()) {
            ((SelectedInstanceCallback) supplier).selectedServiceInstance(response.getServer());
        }
        cachedResponse = response;
        if (callCount > 4) {
            callCount = 0;
        }
        return response;
    }

    private Response<ServiceInstance> selectInstance(List<ServiceInstance> list) {
        if (list.isEmpty()) {
            if (logger.isWarnEnabled()) {
                logger.warn("No available servers for service: " + serviceName);
            }
            return new EmptyResponse();
        }

        if (list.size() == 1) {
            return new DefaultResponse(list.get(0));
        }

        int pos = this.index.incrementAndGet() & Integer.MAX_VALUE;

        ServiceInstance instance = list.get(pos % list.size());
        return new DefaultResponse(instance);
    }
}

最后，在应用上下文中配置负载均衡器并使用它进行服务调用：

@Configuration
@LoadBalancerClient(name = "SERVICE-PROVIDER", configuration = CustomBalancerSetup.class)
public class AppConfig {

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

@RestController
@Slf4j
@RequestMapping("/client")
public class ClientController {

    private RestTemplate template;

    private static final String BASE_URI = "http://SERVICE-PROVIDER";

    @PostMapping("/order/create")
    public Response createOrder(@RequestBody Order order){
        log.info("Starting to create order...");
        return template.postForObject(BASE_URI+"/order/create", order, Response.class);
    }

    @GetMapping("/order/{id}")
    public Response<Order> getOrderById(@PathVariable("id") Long id){
        log.info("Fetching order by ID...");
        return template.getForObject(BASE_URI+"/order/"+id, Response.class);
    }

    @Autowired
    public void setRestTemplate(RestTemplate template) {
        this.template = template;
    }
}