OpenFeign统一Fallback处理

@Slf4j
@Configuration(proxyBeanMethods = false)
public class FeignLoadBalancedConfiguration {

    @Bean
    public LoadBalancerFeignClient feignClient(CachingSpringLoadBalancerFactory cachingFactory,
                                               SpringClientFactory clientFactory) {
        return new LoadBalancerFeignClient(new Client.Default(null, null), cachingFactory,
                clientFactory) {
            @Override
            public Response execute(Request request, Request.Options options) {
                Map<String, Collection<String>> headers = new HashMap<>(2);
                headers.put("content-type", Collections.singletonList("application/json"));
                headers.put("transfer-encoding", Collections.singletonList("chunked"));

                Response.Builder builder = Response.builder()
                        .status(200).headers(headers)
                        .request(request);
                try {
                    Response resp = super.execute(request, options);
                    if (Objects.equals(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, resp.status())) {
                        log.error("服务内部错误, req: {}, data: {}", request.url(),
                                new String(Optional.ofNullable(request.body()).orElse(new byte[]{}, StandardCharsets.UTF_8));
                        return builder.body(JSONObject.toJSONBytes(RestResult.fail("服务内部错误"))).build();
                    }
                    return resp;
                } catch (Exception e) {
                    log.error("服务不可用, req: {}, data: {}", request.url(),
                            new String(Optional.ofNullable(request.body()).orElse(new byte[]{}, StandardCharsets.UTF_8));
                    return builder.body(JSONObject.toJSONBytes(RestResult.fail("服务不可用"))).build();
                }
            }
        };
    }
}