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

男娘i 2022-12-29 04:45 109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][SpringCloud Hoxton_ _ SpringCloud alibaba_3_-- Ribbon] ##

### 一、概述 ###

#### 1、OpenFeign是什么 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 1]  
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][https_github.com_spring-cloud_spring-cloud-openfeign]

#### 2、能干嘛 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 2]

#### 3、Feign和OpenFeign两者区别 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 3]

### 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  
![在这里插入图片描述][20201221005633834.png]

#### 2、POM ####

<?xml version="1.0" encoding="UTF-8"?>
    <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">
        <parent>
            <artifactId>cloud2020</artifactId>
            <groupId>com.atguigu.springcloud</groupId>
            <version>1.0-SNAPSHOT</version>
        </parent>
        <modelVersion>4.0.0</modelVersion>
    
        <artifactId>cloud-consumer-feign-order80</artifactId>
    
    
        
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            <dependency>
                <groupId>com.atguigu.springcloud</groupId>
                <artifactId>cloud-api-common</artifactId>
                <version>${project.version}</version>
            </dependency>
            <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>
    
            <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>
    </project>

#### 3、YAML ####

server:
      port: 80
    eureka:
      client:
        register-with-eureka: false
        service-url:
          defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka

#### 4、主启动类 ####

package com.atguigu.springcloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableFeignClients
    public class OrderFeignMain80 { 
        public static void main(String[] args) { 
            SpringApplication.run(OrderFeignMain80.class,args);
        }
    }

#### 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 #####

package com.atguigu.springcloud.service;
    
    import com.atguigu.springcloud.entities.CommonResult;
    import com.atguigu.springcloud.entities.Payment;
    import feign.Param;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.stereotype.Component;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    
    @Component
    @FeignClient(value = "CLOUD-PAYMENT-SERVICE")
    public interface PaymentFeignService { 
    
        @GetMapping(value = "/payment/get/{id}")
        public CommonResult getPaymentById(@PathVariable("id") Long id);
    }

##### ③、控制层Controller #####

package com.atguigu.springcloud.controller;
    
    import com.atguigu.springcloud.entities.CommonResult;
    import com.atguigu.springcloud.entities.Payment;
    import com.atguigu.springcloud.service.PaymentFeignService;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    
    @RestController
    public class OrderFeignController { 
    
        @Resource
        private PaymentFeignService paymentFeignService;
    
        @GetMapping(value = "/consumer/payment/get/{id}")
        public CommonResult<Payment> getPaymentById(@PathVariable("id") Long id){ 
           return paymentFeignService.getPaymentById(id);
        }
    }

#### 6、测试 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 4]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 5]

#### 7、小总结 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 6]

### 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 #####

@GetMapping(value = "/payment/feign/timeout")
    public String paymentFeignTimeout(){ 
        try {  TimeUnit.SECONDS.sleep(3); }catch (Exception e) { e.printStackTrace();}
        return serverPort;
    }

##### ②、服务消费方80添加超时方法PaymentFeignService #####

@GetMapping(value = "/payment/feign/timeout")
    public String paymentFeignTimeout();

##### ③、服务消费方80添加超时方法OrderFeignController #####

@GetMapping(value = "/consumer/payment/feign/timeout")
    public String paymentFeignTimeout(){ 
       return paymentFeignService.paymentFeignTimeout();
    }

##### ④、测试 #####

http://localhost/consumer/payment/feign/timeout  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 7]

#### 2、OpenFeign默认等待一秒钟，超过后报错 ####

#### 3、是什么 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 8]  
OpenFeign默认支持Ribbon  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 9]

#### 4、YML文件里需要开启OpenFeign客户端超时控制 ####

ribbon:
      ReadTimeout:  5000
      ConnectTimeout: 5000

### 四、OpenFeign日志打印功能 ###

#### 1、是什么 ####

![在这里插入图片描述][20201221010742407.png]

#### 2、日志级别 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 10]

#### 3、配置日志bean ####

package com.atguigu.springcloud.config;
    
    import feign.Logger;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    @Configuration
    public class FeignConfig { 
    
        @Bean
        Logger.Level feignLoggerLevel(){ 
            return Logger.Level.FULL;
        }
    }

#### 4、YML文件里需要开启日志的Feign客户端 ####

logging:
      level:
        com.atguigu.springcloud.service.PaymentFeignService: debug

#### 5、后台日志查看 ####

## 下一篇：[SpringCloud Hoxton版 + SpringCloud alibaba学习笔记（5）-- Gateway新一代网关][SpringCloud Hoxton_ _ SpringCloud alibaba_5_-- Gateway] ##

[SpringCloud Hoxton_ _ SpringCloud alibaba_3_-- Ribbon]: https://blog.csdn.net/exodus3/article/details/111322286
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70]: /images/20221120/13bfac49769446c7884b0fd5917c4529.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 1]: /images/20221120/3d8c78b1782f4c68b21246c325ffd357.png
[https_github.com_spring-cloud_spring-cloud-openfeign]: https://github.com/spring-cloud/spring-cloud-openfeign
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 2]: /images/20221120/87cd8a2d87204a97a454a636edf46b30.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 3]: /images/20221120/a70f3a35203a489c88e4728cbc6f9917.png
[20201221005633834.png]: /images/20221120/88d13ebd6bf8482ab9157b3ec27a738a.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 4]: /images/20221120/6ecb9cf7cef64a1cb46803a6964b2cf2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 5]: /images/20221120/321d6acfb995447b95728fe6c5eca0c2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 6]: /images/20221120/0ba485a708974e6aaa4f40947992d946.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 7]: /images/20221120/183263d860a24a429b6d4a396d9a6824.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 8]: /images/20221120/74324f6e0c5b44dfbd229771161b34a2.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 9]: /images/20221120/e1016dccd50041c0bad66e0f22489dfc.png
[20201221010742407.png]: /images/20221120/8cf532da7d9c42dda4a4a5b6472b7b61.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2V4b2R1czM_size_16_color_FFFFFF_t_70 10]: /images/20221120/ba81c2aa967a45f2b365c8b74b2ecec4.png
[SpringCloud Hoxton_ _ SpringCloud alibaba_5_-- Gateway]: https://blog.csdn.net/exodus3/article/details/111083614