SpringCloud Hoxton版 + SpringCloud alibaba学习笔记（4）-- OpenFeign服务接口调用

男娘i 2022-12-29 04:45 224阅读 0赞

上一篇：SpringCloud Hoxton版 + SpringCloud alibaba学习笔记（3）— Ribbon负载均衡服务调用

一、概述

1、OpenFeign是什么

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Feign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，只需创建一个接口并在接口上添加注解即可
https://github.com/spring-cloud/spring-cloud-openfeign

2、能干嘛

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3、Feign和OpenFeign两者区别

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二、OpenFeign使用步骤

接口+注解：微服务调用接口+@FeignClient

1、新建cloud-consumer-feign-order80

Feign在消费端使用
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2、POM

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  3.     <parent>
  4.         <artifactId>cloud2020</artifactId>
  5.         <groupId>com.atguigu.springcloud</groupId>
  6.         <version>1.0-SNAPSHOT</version>
  7.     </parent>
  8.     <modelVersion>4.0.0</modelVersion>
  10.     <artifactId>cloud-consumer-feign-order80</artifactId>
  13.     <!--openfeign-->
  14.     <dependencies>
  15.         <dependency>
  16.             <groupId>org.springframework.cloud</groupId>
  17.             <artifactId>spring-cloud-starter-openfeign</artifactId>
  18.         </dependency>
  19.         <dependency>
  20.             <groupId>org.springframework.cloud</groupId>
  21.             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
  22.         </dependency>
  23.         <dependency>
  24.             <groupId>com.atguigu.springcloud</groupId>
  25.             <artifactId>cloud-api-common</artifactId>
  26.             <version>${project.version}</version>
  27.         </dependency>
  28.         <dependency>
  29.             <groupId>org.springframework.boot</groupId>
  30.             <artifactId>spring-boot-starter-web</artifactId>
  31.         </dependency>
  33.         <dependency>
  34.             <groupId>org.springframework.boot</groupId>
  35.             <artifactId>spring-boot-starter-actuator</artifactId>
  36.         </dependency>
  38.         <dependency>
  39.             <groupId>org.springframework.boot</groupId>
  40.             <artifactId>spring-boot-devtools</artifactId>
  41.             <scope>runtime</scope>
  42.             <optional>true</optional>
  43.         </dependency>
  45.         <dependency>
  46.             <groupId>org.projectlombok</groupId>
  47.             <artifactId>lombok</artifactId>
  48.             <optional>true</optional>
  49.         </dependency>
  50.         <dependency>
  51.             <groupId>org.springframework.boot</groupId>
  52.             <artifactId>spring-boot-starter-test</artifactId>
  53.             <scope>test</scope>
  54.         </dependency>
  55.     </dependencies>
  56. </project>

3、YAML

  1. server:
  2.   port: 80
  3. eureka:
  4.   client:
  5.     register-with-eureka: false
  6.     service-url:
  7.       defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka

4、主启动类

  1. package com.atguigu.springcloud;
  3. import org.springframework.boot.SpringApplication;
  4. import org.springframework.boot.autoconfigure.SpringBootApplication;
  5. import org.springframework.cloud.openfeign.EnableFeignClients;
  7. @SpringBootApplication
  8. @EnableFeignClients
  9. public class OrderFeignMain80 { 
  10.     public static void main(String[] args) { 
  11.         SpringApplication.run(OrderFeignMain80.class,args);
  12.     }
  13. }

5、业务类

①、业务逻辑接口+@FeignClient配置调用provider服务
②、新建PaymentFeignService接口并新增注解@FeignClient
  1. package com.atguigu.springcloud.service;
  3. import com.atguigu.springcloud.entities.CommonResult;
  4. import com.atguigu.springcloud.entities.Payment;
  5. import feign.Param;
  6. import org.springframework.cloud.openfeign.FeignClient;
  7. import org.springframework.stereotype.Component;
  8. import org.springframework.web.bind.annotation.GetMapping;
  9. import org.springframework.web.bind.annotation.PathVariable;
  11. @Component
  12. @FeignClient(value = "CLOUD-PAYMENT-SERVICE")
  13. public interface PaymentFeignService { 
  15.     @GetMapping(value = "/payment/get/{id}")
  16.     public CommonResult getPaymentById(@PathVariable("id") Long id);
  17. }
③、控制层Controller
  1. package com.atguigu.springcloud.controller;
  3. import com.atguigu.springcloud.entities.CommonResult;
  4. import com.atguigu.springcloud.entities.Payment;
  5. import com.atguigu.springcloud.service.PaymentFeignService;
  6. import org.springframework.web.bind.annotation.GetMapping;
  7. import org.springframework.web.bind.annotation.PathVariable;
  8. import org.springframework.web.bind.annotation.RestController;
  10. import javax.annotation.Resource;
  12. @RestController
  13. public class OrderFeignController { 
  15.     @Resource
  16.     private PaymentFeignService paymentFeignService;
  18.     @GetMapping(value = "/consumer/payment/get/{id}")
  19.     public CommonResult<Payment> getPaymentById(@PathVariable("id") Long id){ 
  20.        return paymentFeignService.getPaymentById(id);
  21.     }
  22. }

6、测试

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7、小总结

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三、OpenFeign超时控制

1、超时设置，故意设置超时演示出错情况

①、服务提供方8001故意写暂停程序
  1. @GetMapping(value = "/payment/feign/timeout")
  2. public String paymentFeignTimeout(){ 
  3.     try {  TimeUnit.SECONDS.sleep(3); }catch (Exception e) { e.printStackTrace();}
  4.     return serverPort;
  5. }
②、服务消费方80添加超时方法PaymentFeignService
  1. @GetMapping(value = "/payment/feign/timeout")
  2. public String paymentFeignTimeout();
③、服务消费方80添加超时方法OrderFeignController
  1. @GetMapping(value = "/consumer/payment/feign/timeout")
  2. public String paymentFeignTimeout(){ 
  3.    return paymentFeignService.paymentFeignTimeout();
  4. }
④、测试

http://localhost/consumer/payment/feign/timeout
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2、OpenFeign默认等待一秒钟，超过后报错

3、是什么

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OpenFeign默认支持Ribbon
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4、YML文件里需要开启OpenFeign客户端超时控制

  1. ribbon:
  2.   ReadTimeout:  5000
  3.   ConnectTimeout: 5000

四、OpenFeign日志打印功能

1、是什么

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2、日志级别

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3、配置日志bean

  1. package com.atguigu.springcloud.config;
  3. import feign.Logger;
  4. import org.springframework.context.annotation.Bean;
  5. import org.springframework.context.annotation.Configuration;
  7. @Configuration
  8. public class FeignConfig { 
  10.     @Bean
  11.     Logger.Level feignLoggerLevel(){ 
  12.         return Logger.Level.FULL;
  13.     }
  14. }

4、YML文件里需要开启日志的Feign客户端

  1. logging:
  2.   level:
  3.     com.atguigu.springcloud.service.PaymentFeignService: debug

5、后台日志查看

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