OpenFeign是什么

OpenFeign是一个声明式web服务客户端，让web服务调用更容易，只需要在接口上进行注解配置即可

能干嘛

Feign对Ribbon进行了封装，使得接口和调用的路径进行绑定，以注解的形式配置即可

OpenFeign和Feign的区别

1、都内置了Ribbon
2、Feign是Netflix公司写的，OpenFeign是SpringCloud写的
3、OpenFeign支持SpringMvc注解，如@RequestMapping等

demo

1、建module
consumer-feign-order80
2、改pom

cloud2020com.atguigu.springcloud1.0-SNAPSHOT4.0.0cloud-consumer-feign-order80org.springframework.cloudspring-cloud-starter-openfeignorg.springframework.cloudspring-cloud-starter-netflix-eureka-clientcom.atguigu.springcloudcloud-api-commons${project.version}compileorg.springframework.bootspring-boot-starter-weborg.springframework.bootspring-boot-starter-actuatororg.projectlomboklomboktrueorg.springframework.bootspring-boot-starter-testtest

3、配yml

server:port: 80#spring:
#  application:
#    name: cloud-order-serviceeureka:client:register-with-eureka: false # 不注册进eureka服务中心service-url:defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/

4、主启动

@SpringBootApplication
@EnableFeignClients // 启动feign
public class CloudConsumerFeignOrder80Application {public static void main(String[] args) {SpringApplication.run(CloudConsumerFeignOrder80Application.class, args);System.out.println("启动成功");}}

5、业务类

@Component
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {@GetMapping(value = "/payment/get/{id}")CommonResult getPaymentById(@PathVariable("id") Long id);@GetMapping(value = "/payment/feign/timeout")String paymentFeignTimeout();
}

6、controller

@RestController
@RequestMapping("consumer")
@Slf4j
public class OrderFeignController {@Resourceprivate PaymentFeignService paymentFeignService;@GetMapping(value = "/payment/get/{id}")public CommonResult getPaymentById(@PathVariable("id") Long id) {return paymentFeignService.getPaymentById(id);}@GetMapping(value = "/payment/feign/timeout")public String paymentFeignTimeout() {// OpenFeign客户端一般默认等待1秒钟return paymentFeignService.paymentFeignTimeout();}
}

7、测试
http://localhost/consumer/payment/get/31

超时控制

1、生产者故意sleep5s

    @GetMapping("feign/timeout")public String getFeignTimeOut() {try {TimeUnit.SECONDS.sleep(3);} catch (InterruptedException e) {e.printStackTrace();}return serverPort;}

2、消费者service添加超时方法

    String paymentFeignTimeout();

3、消费者controller添加超时方法

    @GetMapping(value = "/payment/feign/timeout")public String paymentFeignTimeout() {// OpenFeign客户端一般默认等待1秒钟return paymentFeignService.paymentFeignTimeout();}

4、测试
http://localhost/consumer/payment/feign/timeout
5、OpenFeign默认等待一秒钟，超过后报错
6、yml设置超时控制

#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

日志打印功能

1、是什么？
对feign的链路调用情况进行监控和输出
2、日志级别：NONE、BASIC、HEADERS、FULL
3、配置日志bean

@Configuration
public class FeignConfig {/*** NONE,* BASIC,* HEADERS,* FULL;* 
* 日志级别** @return*/@BeanLogger.Level feignLoggerLevel() {return Logger.Level.FULL;}
}

4、yml配置

logging:level:# feign日志以 debug 级别监控 com.atguigu.springcloud.service.PaymentFeignService 接口com.atguigu.springcloud.service.PaymentFeignService: debug

5、后台查看日志