新建ums工程（使用OpenFeign）-马育民老师

# 关系图

[![](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-233115.png)](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-233115.png)

# 创建 module

在父工程中新建 module `ums_openfeign`

# 添加依赖

### 添加 openfeign 依赖

修改pom.xml文件，添加依赖

```

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

### 完整依赖

```
<dependencies>
    
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>top.malaoshi</groupId>
        <artifactId>common</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>
```

# application.yml

从ums工程中，复制`application.yml`粘贴到该工程中

# 主启动类

要加上`@EnableFeignClients`

不需要 `@EnableEurekaClient`

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

# 创建接口

OpenFeign 通过接口和注解即可实现web service client，简化操作，注解中的url 就是 原Controller 中的url：

[![](https://www.malaoshi.top/upload/pic/eureka/QQ20210108152028.png)](https://www.malaoshi.top/upload/pic/eureka/QQ20210108152028.png)

```
package malaoshi.ums.clients;

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.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import top.malaoshi.entities.Notice;
import top.malaoshi.json.CommonResult;

@Component
@FeignClient(value="NOTICE-SERVICE") //notice微服务名称
public interface NoticeClient {
    //notice服务的url
    @GetMapping(value="/getNoticeById/{id}")
    public CommonResult<Notice> getNoticeById(@PathVariable("id") String id);

//notice服务的url
    @PostMapping(value="/sendNotice")
    public CommonResult sendNotice(@RequestBody Notice notice);
}
```

##### 解释：
- `@FeignClient(value="NOTICE-SERVICE")`：注解中是eureka server中微服务的名字，如下图：
[![](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-200357.png)](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-200357.png)

- 方法名及注解，是从`NOTICE-SERVICE`服务的controller中复制过来的，如下图：
[![](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-225318.png)](https://www.malaoshi.top/upload/pic/springcloud/QQ20200615-225318.png)

# 创建controller

```
package malaoshi.ums.controllers;

import lombok.extern.slf4j.Slf4j;
import malaoshi.ums.clients.NoticeClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import top.malaoshi.entities.Notice;
import top.malaoshi.json.CommonResult;

import javax.annotation.Resource;

@RestController
@Slf4j
public class FollowController {

@Resource
    private NoticeClient noticeClient;

@PostMapping(value="/follow")
    public CommonResult follow(Notice notice){

return noticeClient.sendNotice(notice);
    }

@GetMapping(value="/getNotice/{id}")
    public CommonResult getNotice(@PathVariable("id") String id){
        log.info("---"+id);
        return noticeClient.getNoticeById(id);
    }
}
```

原文出处：http://www.malaoshi.top/show_1EF5iMiuMztc.html