ribbon还没测试，还有配置文件中具体是什么也还没搞太清楚

使用feign的注意事项：

1. feignClient接口中方法的定义，
2. feignClient返回值为复杂对象时，器类型必须有午餐构造函数，dubbo对返回的要求是必须实现序列化接口，

简单Demo记录

三个模块：

• govern_center : 注册中心
• eurekaClient : 服务提供模块
• eureka_consumer : 服务消费模块

govern_center

pom.xml

eureka-server这个依赖依赖了web-starter，并且在java9的环境下，需要额外引入jaxb-api

<dependencies>
        <!-- 导入Eureka服务的依赖 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.4.0-b180725.0427</version>
        </dependency>
    </dependencies>

application.yml

server:
  port: 50101 #服务端口
spring:
  application:
    name: xc-govern-center #指定服务名
eureka:
  client:
    registerWithEureka: false #服务注册，是否将自己注册到Eureka服务中
    fetchRegistry: false #服务发现，是否从Eureka中获取注册信息
    serviceUrl: #Eureka客户端与Eureka服务端的交互地址，高可用状态配置对方的地址，单机状态配置自己（如果不配置则默认本机8761端口）
      defaultZone: http://localhost:50101/eureka/
  server:
    enable-self-preservation: false #是否开启自我保护模式
    eviction-interval-timer-in-ms: 60000 #服务注册表清理间隔（单位毫秒，默认是60*1000）

Application.java

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

eurekaClient

pom.xml

eureka-client不含web-starter,需要额外引入

 <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.4.0-b180725.0427</version>
        </dependency>
    </dependencies>

application.yml

eureka:
  client:
    registerWithEureka: true #服务注册开关
    fetchRegistry: true #服务发现开关
    serviceUrl: #Eureka客户端与Eureka服务端进行交互的地址，多个中间用逗号分隔
      defaultZone: http://localhost:50101/eureka/
  instance:
    prefer-ip-address:  true  #将自己的ip地址注册到Eureka服务中
    ip-address: 127.0.0.1
    instance-id: myFeign:5678 #指定实例id
server:
  port: 5678
spring:
  application:
    name: myFeign

Application.java

@EnableDiscoveryClient
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class);
    }
}

FeignTest.java

@RestController
public class FeignTest {

    @GetMapping("/my/feign/{id}")
    public String myFeign(@PathVariable("id") String id) {

        return "this is a feign Test id：" + id;
    }
}

eureka_consumer

pom.xml

<dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.netflix.feign</groupId>
            <artifactId>feign-okhttp</artifactId>
            <version>8.18.0</version>
        </dependency>
    </dependencies>

application.yml

eureka:
  client:
    registerWithEureka: true #服务注册开关
    fetchRegistry: true #服务发现开关
    serviceUrl: #Eureka客户端与Eureka服务端进行交互的地址，多个中间用逗号分隔
      defaultZone: http://localhost:50101/eureka/
  instance:
    prefer-ip-address:  true  #将自己的ip地址注册到Eureka服务中
    ip-address: 127.0.0.1
    instance-id: xc_huang:5679 #指定实例id
server:
  port: 5679
spring:
  application:
    name: xc_huang

Appliaction.java

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

MyFeignConsumer.java

@FeignClient(value = "MYFEIGN")
public interface MyFeignConsumer {
    @GetMapping("/my/feign/{id}")
    String myFeign(@PathVariable("id") String id);
}

FeignController.java用于测试

@RestController
public class FeignController {

    @Autowired
    private MyFeifnConsumer consumer;

    @RequestMapping("/test/{id}")
    public String feignTest(@PathVariable("id") String id) {
        String s = consumer.myFeign(id);
        System.out.println(s);
        return s;
    }
}

结果：

1556280533488.png