SpringCloud Feign实战（二）

一，新建Feign工程microservicecloud-consumer-dept-feign，拷贝microservicecloud-consumer-dept-80这个工程的配置和程序

二，修改配置文件pom.xml 引入Feign依赖

  <!--Feign的依赖引入--><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-feign</artifactId></dependency>

三，修改我们的启动类为 DeptConsumer80_Feign_App

package atguigu.springcloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;@SpringBootApplication
@EnableEurekaClient
public class DeptConsumer80_Feign_App {public static void main(String[] args) {SpringApplication.run(DeptConsumer80_Feign_App.class, args);}
}

四，yml配置文件不用修改

五，修改api（microservicecloud-api）添加新的接口DeptClientService

新增新的注解@FeignClient

package com.atguigu.springcloud.service;import java.util.List;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.atguigu.springcloud.entities.Dept;/*** * @Description: 修改microservicecloud-api工程，根据已经有的DeptClientService接口* @author zzyy* @date 2019年10月20日*/
@FeignClient(value = "MICROSERVICECLOUD-DEPT")
public interface DeptClientService
{@RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)public Dept get(@PathVariable("id") long id);@RequestMapping(value = "/dept/list", method = RequestMethod.GET)public List<Dept> list();@RequestMapping(value = "/dept/add", method = RequestMethod.POST)public boolean add(Dept dept);
}

这样就已经编码完成但是api是我们所有工程的公共部分

注意：因为是公共部分，我们要重新编译，Build Module 'microservicecloud-api'

六，我们编写到这来我们回到microservicecloud-consumer-dept-feign工程修改Controller，

package atguigu.springcloud.controller;import com.atguigu.springcloud.entities.Dept;
import com.atguigu.springcloud.service.DeptClientService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;
import java.util.List;@RestController
@RequestMapping("/consumer")
public class DeptController_Consumer {//@Autowired@Resourceprivate DeptClientService service;@RequestMapping(value = "/dept/get/{id}")public Dept get(@PathVariable("id") Long id){return this.service.get(id);}@RequestMapping(value = "/dept/list")public List<Dept> list(){return this.service.list();}@RequestMapping(value = "/dept/add")public Object add(Dept dept){return this.service.add(dept);}
}

七，我们前面在api定义了新的接口，加了@FeignClient注解使用Feign，那我们的主启动类就要开启，修改主启动类

添加新的注解@EnableFeignClients(basePackages= {"com.atguigu.springcloud"}) 表示开启新的feign调用方式

package atguigu.springcloud;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(basePackages= {"com.atguigu.springcloud"})
@ComponentScan("com.atguigu.springcloud")
public class DeptConsumer80_Feign_App {public static void main(String[] args) {SpringApplication.run(DeptConsumer80_Feign_App.class, args);}
}

到这来我们基本就已经完成了基本的编码，那我们来测试下

关于启动：Eureka集群搭建和启动参考：https://blog.csdn.net/ywl470812087/article/details/102594937

启动3个微服务提供者，如果不懂微服务提供者实现请参考https://blog.csdn.net/ywl470812087/article/details/102535582

启动Feign工程：

访问：http://localhost/consumer/dept/get/1

上图测试结果看：默认使用了轮询的负载均衡

总结：