openFeign是一个声明式的Web 服务客户端，让编写Web服务客户端变得非常容易，只需创建一个借口并在借口上添加注解即可。
用于服务调用方

1.pom

<dependencies>
    <!--openfeign-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <!--eureka client-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <!-- 引入自己定义的api通用包，可以使用Payment支付Entity -->
    <dependency>
        <groupId>com.atguigu.springcloud</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>${project.version}</version>
    </dependency>
    <!--web-->
    <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>
    <!--一般基础通用配置-->
    <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>

2.application.yml

server:
  port: 80

spring:
  application:
    name: cloud-consumer-feign-order


#设置feign客户端超时时间(OpenFeign默认支持ribbon)
ribbon:
  #指的是建立连接所用的时间，适用于网络状况正常的情况下,两端连接所用的时间
  ReadTimeout: 5000
  #指的是建立连接后从服务器读取到可用资源所用的时间
  ConnectTimeout: 5000

logging:
  level:
    # feign日志以什么级别监控哪个接口
    org.mc.mycloud.service.PaymentFeignService: debug

eureka:
  client:
    #表示是否将自己注册进EurekaServer默认为true。
    register-with-eureka: true
    #是否从EurekaServer抓取已有的注册信息，默认为true。单节点无所谓，集群必须设置为true才能配合ribbon使用负载均衡
    fetchRegistry: true
    service-url:
      #单机版
      #      defaultZone: http://localhost:7001/eureka
      # 集群版
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka
      #主机名称 服务修改
  instance:
    instance-id: order80
    #访问路径可以显示IP地址
    prefer-ip-address: true
#    #Eureka客户端向服务端发送心跳的时间间隔，单位为秒(默认是30秒)
#    #lease-renewal-interval-in-seconds: 1
#    #Eureka服务端在收到最后一次心跳后等待时间上限，单位为秒(默认是90秒)，超时将剔除服务
#    #lease-expiration-duration-in-seconds: 2

3.主启动

@SpringBootApplication
@EnableFeignClients //说明是feign 客户端
public class FeignOrderMain80 {
    public static void main(String[] args) {
        SpringApplication.run(FeignOrderMain80.class, args);
    }
}

4.service接口

@Component
//作为feign组件的接口 以及将要调用的服务名称
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {

    @GetMapping(value = "/payment/get/{id}")
    public CommonResult getPaymentById(@PathVariable("id") Long id);

    @PostMapping(value = "/payment/creat")
    public CommonResult creat(@RequestBody Payment payment);

}

5.controller调用

@RestController
@Slf4j
public class FeignOrderController {
    @Resource
    public PaymentFeignService paymentFeignService;


    @GetMapping(value = "/consumer/payment/get/{id}")
    public CommonResult getPaymentById(@PathVariable("id") Long id) {
        return paymentFeignService.getPaymentById(id);
    }

}

6.配置详细日志

FeignConfig.java

@Configuration
public class FeignConfig {

    @Bean
    Logger.Level  feignLoggerLevel(){
        return Logger.Level.FULL;
    }
}

application.xml

logging:
  level:
    # feign日志以什么级别监控哪个接口
    org.mc.mycloud.service.PaymentFeignService: debug