SpringCloud之Feign与Hystrix的整合

配置信息

server:
  port: 8010
spring:
  application:
    name: microservice-consumer-order
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

feign:
  hystrix:
    enabled: true
# 说明：请务必注意，从Spring Cloud Dalston开始，Feign默认是不开启Hystrix的。
# 因此，如使用Dalston请务必额外设置属性：feign.hystrix.enabled=true，否则
断路器不会生效。
# 而，Spring Cloud Angel/Brixton/Camden中，Feign默认都是开启Hystrix的。
无需设置该属性。

UserFeignClient

/**
 * Feign的fallback测试
 * 使用@FeignClient的fallback属性指定回退类
 */
@FeignClient(name = "microservice-provider-user",
 fallback = FeignClientFallback.class/*, 
 configuration = FeignDisableHystrixConfiguration.class*/)
public interface UserFeignClient {
  @RequestMapping(value = "/{id}", method = RequestMethod.GET)
  public User findById(@PathVariable("id") Long id);

}

/**
 * 回退类FeignClientFallback需实现Feign Client接口
 * FeignClientFallback也可以是public class，没有区别
 */
@Component
class FeignClientFallback implements UserFeignClient {
  @Override
  public User findById(Long id) {
    User user = new User();
    user.setId(-1L);
    user.setUsername("默认用户");
    return user;
  }
}

OrderController

@RestController
public class OrderController {
  @Autowired
  private UserFeignClient userFeignClient;

  @GetMapping("/user/{id}")
  public User findById(@PathVariable Long id) {
    return userFeignClient.findById(id);
  }
}

启动类不需要加Hystrix的注解,有配置文件配置

@EnableDiscoveryClient
@SpringBootApplication
@EnableFeignClients
public class ConsumerOrderApplication {
  public static void main(String[] args) {
    SpringApplication.run(ConsumerOrderApplication.class, args);
  }
}

Feign禁用Hystrix

server:
  port: 8010
spring:
  application:
    name: microservice-consumer-order
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

feign:
  hystrix:
    enabled: false
# 说明：请务必注意，从Spring Cloud Dalston开始，Feign默认是不开启Hystrix的。
否则断路器不会生效。
# 而，Spring Cloud Angel/Brixton/Camden中，Feign默认都是开启Hystrix的。
无需设置该属性。

package com.tuling.cloud.study.user.feign;

import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.tuling.cloud.study.user.entity.User;

/**
 * Feign的fallback测试
 * 使用@FeignClient的fallback属性指定回退类
 */
@FeignClient(name = "microservice-provider-user",
 fallback = FeignClientFallback.class, 
 configuration = FeignDisableHystrixConfiguration.class)
public interface UserFeignClient {
  @RequestMapping(value = "/{id}", method = RequestMethod.GET)
  public User findById(@PathVariable("id") Long id);

}

/**
 * 回退类FeignClientFallback需实现Feign Client接口
 * FeignClientFallback也可以是public class，没有区别
 */
@Component
class FeignClientFallback implements UserFeignClient {
  @Override
  public User findById(Long id) {
    User user = new User();
    user.setId(-1L);
    user.setUsername("默认用户");
    return user;
  }
}

/*
*
* 为Feign禁用Hystrix功能
*
*/


@Configuration
public class FeignDisableHystrixConfiguration {  

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