详解springcloud 基于feign的服务接口的统一hystrix降级处理

@FeignClient(name="springcloud-nacos-producer", qualifier="productApiService", contextId="productApiService", fallback=ProductFallbackApiService.class)
public interface ProductApiService {

 /**
  * 创建商品
  * @param product
  */
 @PostMapping(value="/api/product/add", produces=APPLICATION_JSON, consumes=APPLICATION_JSON)
 public Result<Long> createProduct(@RequestBody Product product);
 
 /**
  * 修改商品
  * @param product
  */
 @PutMapping(value="/api/product/update", produces=APPLICATION_JSON, consumes=APPLICATION_JSON)
 public Result<Object> updateProduct(@RequestBody Product product);
 
 /**
  * 删除商品
  * @param productId
  */
 @DeleteMapping(value="/api/product/delete/{productId}", produces=APPLICATION_JSON)
 public Result<Object> deleteProductById(@PathVariable("productId") Long productId);
 
 /**
  * 根据productId获取商品信息
  * @param productId
  * @return
  */
 @GetMapping(value="/api/product/{productId}", produces=APPLICATION_JSON)
 public Result<Product> getProductById(@PathVariable("productId") Long productId);
 
 /**
  * 根据条件查询商品列表(分页、排序)
  * @param condition
  * @param page
  * @param sort
  * @return
  */
 @GetMapping(value="/api/product/list1", produces=APPLICATION_JSON)
 public PageResult<List<Product>> getProductListByPage(@RequestParam Product condition, @RequestParam Page page, @RequestParam Sort sort);
}

@Component
public class ProductFallbackApiService implements ProductApiService {

 private static final HttpStatus SERVICE_UNAVAILABLE = HttpStatus.SERVICE_UNAVAILABLE;
 
 protected <T> Result<T> defaultFallbackResult() {
  return Result.failure().code(String.valueOf(SERVICE_UNAVAILABLE.value())).message(String.format("请求失败：%s, %s", SERVICE_UNAVAILABLE.value(), SERVICE_UNAVAILABLE.getReasonPhrase())).build();
 }
 
 protected <T> PageResult<T> defaultFallbackPageResult() {
  return PageResult.failure().code(String.valueOf(SERVICE_UNAVAILABLE.value())).message(String.format("请求失败：%s, %s", SERVICE_UNAVAILABLE.value(), SERVICE_UNAVAILABLE.getReasonPhrase())).build();
 }
 
 @Override
 public Result<Long> createProduct(Product product) {
  return defaultFallbackResult();
 }

 @Override
 public Result<Object> updateProduct(Product product) {
  return defaultFallbackResult();
 }

 @Override
 public Result<Object> deleteProductById(Long productId) {
  return defaultFallbackResult();
 }

 @Override
 public Result<Product> getProductById(Long productId) {
  return defaultFallbackResult();
 }

 @Override
 public PageResult<List<Product>> getProductListByPage(Product condition, Page page, Sort sort) {
  return defaultFallbackPageResult();
 }

}