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

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：

获得造成fallback的原因：

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

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来源：oschina

链接：https://my.oschina.net/u/2248449/blog/3003903

标签

hystrix

Spring

Spring Cloud