springcloud中Feign服务器调用-Feign与熔断Hystrix配置讲解

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我是靠谱客的博主结实盼望，最近开发中收集的这篇文章主要介绍springcloud中Feign服务器调用-Feign与熔断Hystrix配置讲解，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

1>.Feign的作用：

减少负载（ribbon）与熔断（Hystrix）的配置，用于管理调用服务器。

代替了RestTemplate。

2>.配置：

1.引入pom.xml坐标

<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

2.在启动类添加注解@EnableFeignClients开启Feign服务。

3.创建一个接口，接口上面添加@FeignClient("SERVICE-PROVIDER")参数为服务名。具体方法与controller的方法相似。*注意改接口对一个的方法是服务方提供的接口方法。

package alian.Interface;
import alian.domain.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ResponseBody;
@FeignClient("SERVICE-PROVIDER")
public interface UserControllerFeign{
@GetMapping("user/{id}")
public User findUserbyId(@PathVariable("id") int id);
}

对应的controller的接口方法。

package alian.controller;
import alian.Interface.UserControllerFeign;
import alian.domain.User;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.hystrix.contrib.javanica.annotation.DefaultProperties;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework. web.client.RestTemplate;
import sun.security.jca.GetInstance;
import java.util.List;
@Controller
@RequestMapping("consumer/user")
public class ComsumorController {
@Autowired
private UserControllerFeign userControllerFeign;
@GetMapping("{id}")
@ResponseBody
public String findUserbyId(@PathVariable("id") int id)
{
/*
*
*
*
* 4.通过Feign整合
*
*
* */
return userControllerFeign.findUserbyId(id).toString();
}
}

3>.熔断的整合（Hystrix）

步骤：

1.开启熔断（Feign默认关闭熔断）在application.yml修改开启配置

feign:
hystrix:
enabled: true

2.实例化上述的接口并添加到IOC容器中去（添加@Component）。

package alian.Interface;
import alian.domain.User;
import org.springframework.stereotype.Component;
@Component
public class UserControllerFeignImpl implements UserControllerFeign {
@Override
public User findUserbyId(int id) {
User user = new User();
user.setName("服务器繁忙-请稍后重试");
return user;
}
}

3.在接口上面的注解改成如下所示：

@FeignClient(value = "SERVICE-PROVIDER",fallback = UserControllerFeignImpl.class)

例子如下：

package alian.Interface;
import alian.domain.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ResponseBody;
@FeignClient(value = "SERVICE-PROVIDER",fallback = UserControllerFeignImpl.class)
public interface UserControllerFeign{
@GetMapping("user/{id}")
public User findUserbyId(@PathVariable("id") int id);
}