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); }@Componentclass 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@Slf4jclass 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：
获得造成fallback的原因：
随时随地看视频
