Spring Cloud Eureka 整合 feign 客户端（三）

叁歲伎倆 2021-12-19 00:13 259阅读 0赞

## feign简介 ##

在上一节的 ribbon的demo中是配置并使用 RestTemplate （或 HttpClient）来访问微服务的api的，这里的feign不需要RestTemplate。Feign 是在 Ribbon的基础上进行了一次改进，采用接口的方式， **`只需要创建一个接口，然后在上面添加注解即可`** ，将需要调用的其他服务的方法定义成抽象方法即可， 不需要自己构建http请求。

# 撸代码配置使用feign #

我这里新建了一个公用的模块名字叫做demo-api，里面放实体类等公用的东西。于是我把feign的service也放在里面作为公用部分（不懂不要急，后面做出解释）。demo-api模块没有yml。

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**demo-api的pom依赖包部分**

我这里用的是2.0.0.M2的feign版本，比较新了。

<dependencies>
             
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>2.0.0.M2</version>
            </dependency>
    
        </dependencies>

**DeptClientService.java**

@FeignClient(value = "MICROSERVICE-DEMO")
    
    public interface DeptClientService {
        /**
         * http://MICROSERVICE-DEMO/接口URI
         */
    
        @GetMapping("/dept/list")
        List<Dept> getAll();
    
        @PostMapping("/dept/add")
        boolean add(@RequestBody Dept model);
    
        @GetMapping("/dept/findById/{id}")
        List<Dept> get(@PathVariable("id") Long id);
    
    
        @PostMapping("/dept/delete/{id}")
        boolean delete(@PathVariable("id") Long id);
    
    }

## 配置客户端 ##

模块的目录如下，遮了的目录是没用的目录，不用纠结了：）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjQ3OTk5_size_16_color_FFFFFF_t_70 1][]

**POM的依赖包部分**

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>com.djun.demo</groupId>
                <artifactId>demo-api</artifactId>
                <version>${project.version}</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>${feign.version}</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>springloaded</artifactId>
                <version>${springloaded.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            
            <dependency>
                <groupId>com.netflix.ribbon</groupId>
                <artifactId>ribbon-core</artifactId>
            </dependency>
            <dependency>
                <groupId>com.netflix.ribbon</groupId>
                <artifactId>ribbon-httpclient</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
            </dependency>
        </dependencies>

**application.yml**

server:
      port: 80
    spring:
      application:
        name: demo-consumer-feign
    eureka:
      client:
        register-with-eureka: false
        service-url:
          defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/
          # defaultZone: http://localhost:7001/eureka/

**DeptController\_Consumer.java**

/**
     * created by DJun on 2019/7/1
     */
    
    @RestController
    public class DeptController_Consumer {
    
        @Resource
        private DeptClientService service;
    
        @GetMapping("/test")
        public String test(){
            System.out.println("Hello,World!");
            return "HELLO,WORLD！";
        }
    
        @GetMapping("/consumer/dept/list")
        public List<Dept> getAll(){
            return this.service.getAll();
        }
    
        @PostMapping("/consumer/dept/add")
        public boolean add( @RequestBody Dept model){
            return this.service.add(model);
        }
    
        @GetMapping("/consumer/dept/findById/{id}")
        public List<Dept> get(@PathVariable("id") Long id){
            return this.service.get(id);
        }
    
    
        @PostMapping("/consumer/dept/delete/{id}")
        public boolean delete(@PathVariable("id") Long id){
            return this.service.delete(id);
        }
    
    }

**DeptConsumerFeign80\_App.application**

这里注意一下下面的这个扫的包，我上次没注意这个问题，让我又掉了不少发丝~

/**
     * created by DJun on 2019/7/1
     */
    @SpringBootApplication
    
    @EnableEurekaClient
    // 开启feign服务
    @EnableFeignClients(basePackages = {"com.djun.demo"})
    
    public class DeptConsumerFeign80_App {
        public static void main(String[] args) {
            SpringApplication.run(DeptConsumerFeign80_App.class,args);
        }
    }

到这里配置就结束了，如果要运行起来的话，你是配置的集群的话，先把eureka的全部集群服务端启动起来，然后在将微服务端启动起来，最后才启动这个消费者端。然后访问80端口。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjQ3OTk5_size_16_color_FFFFFF_t_70 2][]

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