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

时间 2019-11-07

标签 spring cloud finchley feign 使用 hystrix 栏目 Spring 繁體版

原文原文链接

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

服务降级

加配置，默认Feign是不启用Hystrix的，须要添加以下配置启用Hystrix，这样全部的Feign Client都会受到Hystrix保护！github
```
feign:
  hystrix:
    enabled: true
```

提供Fallback：spring

@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));
  }
}

得到形成fallback的缘由

@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。app

局部启用

利用Feign配置的自定义，为指定Feign Client指定以下配置类便可，Feign配置自定义详见：跟我学Spring Cloud（Finchley版）-10-Feign深刻ide

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：ui

得到形成fallback的缘由：prototype

本文首发

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