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

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一、概述

1、OpenFeign是什么

在这里插入图片描述
SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第1张图片
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

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第2张图片

3、Feign和OpenFeign两者区别

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第3张图片

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

2、POM


<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>cloud2020artifactId>
        <groupId>com.atguigu.springcloudgroupId>
        <version>1.0-SNAPSHOTversion>
    parent>
    <modelVersion>4.0.0modelVersion>

    <artifactId>cloud-consumer-feign-order80artifactId>


    
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-openfeignartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.cloudgroupId>
            <artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
        dependency>
        <dependency>
            <groupId>com.atguigu.springcloudgroupId>
            <artifactId>cloud-api-commonartifactId>
            <version>${project.version}version>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-actuatorartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
            <scope>runtimescope>
            <optional>trueoptional>
        dependency>

        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        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

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第4张图片
SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第5张图片

7、小总结

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第6张图片

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
SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第7张图片

2、OpenFeign默认等待一秒钟,超过后报错

3、是什么

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第8张图片
OpenFeign默认支持Ribbon
SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第9张图片

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

2、日志级别

SpringCloud Hoxton版 + SpringCloud alibaba学习笔记(4)-- OpenFeign服务接口调用_第10张图片

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

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