SpringCloud-Feign使用fallbackFactory属性打印fallback异常

概述

Feign使用fallbackFactory属性打印fallback异常;

fallbackFactory 是fallback的一个升级版；

创建工程

pom.xml

microservice-consumer-movie-feign-with-hystrix-hystrix-factory/pom.xml

	4.0.0

	microservice-consumer-movie-feign-with-hystrix-hystrix-factory
	jar

	
		com.itmuch.cloud
		microservice-spring-cloud
		0.0.1-SNAPSHOT
	

	
		UTF-8
		UTF-8
		1.8
	

	
		
			org.springframework.boot
			spring-boot-starter-web
		

		
			org.springframework.cloud
			spring-cloud-starter-eureka
		

		
			org.springframework.boot
			spring-boot-starter-actuator
		

		
			org.springframework.cloud
			spring-cloud-starter-feign
		
	

application.yml

spring:
  application:
    name: microservice-consumer-movie-feign-with-hystrix-hystrix-factory
server:
  port: 7901
eureka:
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://user:password123@localhost:8761/eureka
  instance:
    prefer-ip-address: true

MovieController

com.itmuch.cloud.controller.MovieController

package com.itmuch.cloud.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import com.itmuch.cloud.entity.User;
import com.itmuch.cloud.feign.UserFeignClient;

@RestController
public class MovieController {

  @Autowired
  private UserFeignClient userFeignClient;

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

UserFeignClientWithFactory

com.itmuch.cloud.feign.UserFeignClientWithFactory

package com.itmuch.cloud.feign;

public interface UserFeignClientWithFactory extends UserFeignClient {

}

HystrixClientFactory

com.itmuch.cloud.feign.HystrixClientFactory

package com.itmuch.cloud.feign;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import com.itmuch.cloud.entity.User;

import feign.hystrix.FallbackFactory;

@Component
public class HystrixClientFactory implements FallbackFactory {

  private static final Logger LOGGER = LoggerFactory.getLogger(HystrixClientFactory.class);

  @Override
  public UserFeignClient create(Throwable cause) {
    HystrixClientFactory.LOGGER.info("fallback; reason was: {}", cause.getMessage());
    return new UserFeignClientWithFactory() {
      @Override
      public User findById(Long id) {
        User user = new User();
        user.setId(-1L);
        return user;
      }
    };
  }
}

说明：

        如果需要访问作为回退触发器的原因，则可以使用@FeignClient中的fallbackFactory属性。

        为指定的客户端接口定义一个回退工厂。回退工厂必须产生回退类的实例，这些实例实现由FeignClient注释的接口。

    如果同时设置fallback和fallbackfactory不可以的，会有有冲突，fallback生效，fallbackfactory不能使用，fallbackFactory 是fallback的一个升级版，注释fallback设置即可；

UserFeignClient

com.itmuch.cloud.feign.UserFeignClient

package com.itmuch.cloud.feign;

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

import com.itmuch.cloud.entity.User;

@FeignClient(name = "microservice-provider-user", /*fallback = HystrixClientFallback.class, */fallbackFactory = HystrixClientFactory.class)
public interface UserFeignClient {
  @RequestMapping(value = "/simple/{id}", method = RequestMethod.GET)
  public User findById(@PathVariable("id") Long id);
}

说明：

    1）将fallback注释掉；

    2）采用fallbackFactory的方式；

ConsumerMovieFeignApplication

com.itmuch.cloud.ConsumerMovieFeignApplication

package com.itmuch.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;

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

测试

http://localhost:7901/movie/1

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