跟我学Spring Cloud（Finchley版）-14-Feign使用Hystrix

说明：SpringCloud系列笔者自学系列，学习来源是周立的博客  http://www.itmuch.com/ 。而此处转载其博客只是为了方便自己以后的学习。

本篇来源 http://www.itmuch.com/spring-cloud/finchley-14/

Feign默认已经整合了Hystrix，本节详细探讨Feign使用Hystrix的具体细节。

服务降级

• 加配置，默认Feign是不启用Hystrix的，需要添加如下配置启用Hystrix，这样所有的Feign Client都会受到Hystrix保护！

  feign: hystrix: enabled: true

• 提供Fallback：

  @FeignClient(name = "microservice-provider-user", fallback = UserFeignClientFallback.class) public interface UserFeignClient { @GetMapping("/users/{id}") User findById(@PathVariable("id") Long id); } @Component class UserFeignClientFallback implements UserFeignClient { @Override public User findById(Long id) { return new User(id, "默认用户", "默认用户", 0, new BigDecimal(1)); } }

获得造成fallback的原因

@FeignClient(name = "microservice-provider-user", fallbackFactory = UserFeignClientFallbackFactory.class) public interface UserFeignClient { @GetMapping("/users/{id}") User findById(@PathVariable("id") Long id); } @Component @Slf4j class UserFeignClientFallbackFactory implements FallbackFactory<UserFeignClient> { @Override public UserFeignClient create(Throwable throwable) { return new UserFeignClient() { @Override public User findById(Long id) { log.error("进入回退逻辑", throwable); return new User(id, "默认用户", "默认用户", 0, new BigDecimal(1)); } }; } }

Feign启用/禁用Hystrix

全局启用

feign.hystrix.enabled: true

全局禁用

feign.hystrix.enabled: false

或直接省略不写。

局部启用

利用Feign配置的自定义，为指定Feign Client指定如下配置类即可，Feign配置自定义详见：跟我学Spring Cloud（Finchley版）-10-Feign深入

public class FeignDisableHystrixConfiguration { @Bean @Scope("prototype") public HystrixFeign.Builder feignBuilder() { return HystrixFeign.builder(); } }

局部禁用

public class FeignDisableHystrixConfiguration { @Bean @Scope("prototype") public Feign.Builder feignBuilder() { return Feign.builder(); } }

配套代码

服务降级：

• GitHub：https://github.com/eacdy/spring-cloud-study/tree/master/2018-Finchley/microservice-consumer-movie-feign-hystrix
• Gitee：https://gitee.com/itmuch/spring-cloud-study/tree/master/2018-Finchley/microservice-consumer-movie-feign-hystrix

获得造成fallback的原因：

• GitHub：https://github.com/eacdy/spring-cloud-study/tree/master/2018-Finchley/microservice-consumer-movie-feign-hystrix-fallback-factory
• Gitee：https://gitee.com/itmuch/spring-cloud-study/tree/master/2018-Finchley/microservice-consumer-movie-feign-hystrix-fallback-factory

相关文章

• 跟我学Spring Cloud（Finchley版）-13-通用方式使用Hystrix
• 跟我学Spring Cloud（Finchley版）-15-Hystrix监控详解
• 跟我学Spring Cloud（Finchley版）-12-微服务容错三板斧
• Spring Cloud中，如何解决Feign/Ribbon第一次请求失败的问题？
• 跟我学Spring Cloud（Finchley版）-09-Feign