Spring Cloud OpenFeign笔记

本文主要是介绍Spring Cloud OpenFeign笔记，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1.OpenFeign简介

Feign是一种声明式、模板化的HTTP客户端。在Spring Cloud中使用Feign，可以做到使用HTTP请求访问远程服务，就像调用本地方法一样的，开发者完全感知不到这是在调用远程方法，更感知不到在访问HTTP请求。

2.pom.xml依赖

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

3.主启动类上增加注解@EnableFeignClients

@SpringBootApplication
@EnableFeignClients
public class OrderFeignMain80{public static void main(String[] args) {SpringApplication.run(OrderFeignMain80.class,args);}
}

4.创建服务提供方对应的服务的接口类

@FeignClient(value = “CLOUD-PAYMENT-SERVICE”)中的value值对应的就是服务提供方注册到eruka中的服务名称。

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

5.创建controller

@RestController
@Slf4j
public class OrderController {@Resourceprivate PaymentFeignService paymentService;@GetMapping(value = "/consumer/payment/get/{id}")public CommonResult<Payment> query(@PathVariable("id") Long id){return paymentService.getPaymentById(id);}@GetMapping(value = "/consumer/payment/timeout/server")public String getTimeOutServicePort(){return paymentService.getTimeOutServicePort();}
}

6.OpenFeign的超时设置
举个例子:当用户下单时，需要从订单服务中调用支付服务，而支付服务处理请求的时间为3秒，订单服务就会报超时异常。

原因是整合了ribbon，而ribbon中处理请求的默认时长是1秒钟。
调整超时设置配置如下：

ribbon:ReadTimeout: 5000ConnenctTimeout: 5000

还可以通过openFeign修改超时设置

feign:client:config:default:connectTimeout: 10000 #Feign的连接建立超时时间，默认为10秒readTimeout: 60000 #Feign的请求处理超时时间，默认为60

7.修改日志级别

@Configuration
public class FeignConfig {@BeanLogger.Level feignLoggerLevel(){return Logger.Level.FULL;}
}

applicaiton.yml中可以指定各个接口输出什么级别日志。

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

如果是按以上的配置，控制台将能看到完整的请求信息。

2020-11-11 22:47:09.346  INFO 62988 --- [p-nio-81-exec-1] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client CLOUD-PAYMENT-SERVICE initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=CLOUD-PAYMENT-SERVICE,current list of Servers=[100.119.202.39:8002, 100.119.202.39:8001],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone;	Instance count:2;	Active connections count: 0;	Circuit breaker tripped count: 0;	Active connections per server: 0.0;]
},Server stats: [[Server:100.119.202.39:8001;	Zone:defaultZone;	Total Requests:0;	Successive connection failure:0;	Total blackout seconds:0;	Last connection made:Thu Jan 01 08:00:00 CST 1970;	First connection made: Thu Jan 01 08:00:00 CST 1970;	Active Connections:0;	total failure count in last (1000) msecs:0;	average resp time:0.0;	90 percentile resp time:0.0;	95 percentile resp time:0.0;	min resp time:0.0;	max resp time:0.0;	stddev resp time:0.0]
, [Server:100.119.202.39:8002;	Zone:defaultZone;	Total Requests:0;	Successive connection failure:0;	Total blackout seconds:0;	Last connection made:Thu Jan 01 08:00:00 CST 1970;	First connection made: Thu Jan 01 08:00:00 CST 1970;	Active Connections:0;	total failure count in last (1000) msecs:0;	average resp time:0.0;	90 percentile resp time:0.0;	95 percentile resp time:0.0;	min resp time:0.0;	max resp time:0.0;	stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@24aed60f
2020-11-11 22:47:10.346  INFO 62988 --- [erListUpdater-0] c.netflix.config.ChainedDynamicProperty  : Flipping property: CLOUD-PAYMENT-SERVICE.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2020-11-11 22:47:11.352 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] <--- HTTP/1.1 200 (2037ms)
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] connection: keep-alive
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] content-length: 4
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] content-type: text/plain;charset=UTF-8
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] date: Wed, 11 Nov 2020 14:47:11 GMT
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] keep-alive: timeout=60
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] 
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] 8002
2020-11-11 22:47:11.353 DEBUG 62988 --- [p-nio-81-exec-1] c.s.service.PaymentFeignService          : [PaymentFeignService#getTimeOutServicePort] <--- END HTTP (4-byte body)

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