feign hystrix

1.添加依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.guo</groupId>
    <artifactId>guo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <artifactId>guo-feign</artifactId>
  
   <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>
    
</project>

　　

2.添加配置 application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8765
spring:
  application:
    name: guo-feign

　　

3.编写feign接口

package com.guo.feign.service;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(value = "service-hi")
public interface SchedualServiceHi {
    @RequestMapping(value = "/hi",method = RequestMethod.GET)
    String sayHiFromClientOne(@RequestParam(value = "name") String name);
}

　　

4.编写controller

package com.guo.feign.web;

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

import com.guo.feign.service.SchedualServiceHi;

@RestController
public class HiController {


    //编译器报错，无视。 因为这个Bean是在程序启动的时候注入的，编译器感知不到，所以报错。
    @Autowired
    SchedualServiceHi schedualServiceHi;

    @GetMapping(value = "/hi")
    public String sayHi(@RequestParam String name) {
        return schedualServiceHi.sayHiFromClientOne( name );
    }
}

　　

5.编写启动类

package com.guo.feign;

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

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class ServiceFeignApplication {

    public static void main(String[] args) {
        SpringApplication.run( ServiceFeignApplication.class, args );
    }
}

6.在application.yml添加熔断器 hystrix 配置

feign.hystrix.enabled: true

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8765
spring:
  application:
    name: guo-feign

feign.hystrix.enabled: true

7.编写熔断回调接口，必须实现同一接口 SchedualServiceHi

package com.guo.feign.service.fallback;

import org.springframework.stereotype.Component;

import com.guo.feign.service.SchedualServiceHi;

@Component
public class SchedualServiceHiHystric implements SchedualServiceHi {
    @Override
    public String sayHiFromClientOne(String name) {
        return "sorry, you are fail,"+name;
    }
}

8.在接口上指定熔断回调处理类

package com.guo.feign.service;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.guo.feign.service.fallback.SchedualServiceHiHystric;

@FeignClient(value = "service-hi",fallback = SchedualServiceHiHystric.class)
public interface SchedualServiceHi {
    @RequestMapping(value = "/hi",method = RequestMethod.GET)
    String sayHiFromClientOne(@RequestParam(value = "name") String name);
}

　　

9.访问feign接口

http://localhost:8765/hi?name=forezp

当关闭服务提供方 service-hi 在此访问feign接口时会返回

sorry, you are fail,china