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概述

OpenFeign是什么

GitHub:https://github.com/spring-cloud/spring-cloud-openfeign

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

能干嘛

Feign和OpenFeign两者区别

OpenFeign使用步骤(Feign在消费端使用)

接口+注解---------微服务调用接口+@FeignClient

引入坐标

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

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将消费者配置到eureka集群中 yml

server:
  port: 80
eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka
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消费者主启动上加@EnableFeignClients，开启基于OpenFegin的服务调用功能

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);
    }
}
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新建接口加上@FeignClien

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/feign/timeout")
     public String paymentFeignTimeout();
}


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controller

@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);
    }

}
 
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OpenFeign超时控制

服务提供方故意超时执行

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

@Component
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {

     @GetMapping(value = "/payment/feign/timeout")
     public String paymentFeignTimeout();
}
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@RestController
public class OrderFeignController {

    @Resource
    private PaymentFeignService paymentFeignService;
   @GetMapping(value = "/consumer/payment/feign/timeout")
   public String paymentFeignTimeout(){
      return paymentFeignService.paymentFeignTimeout();
   }
 
}
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测试：http://localhost/consumer/payment/feign/timeout

提示访问超时

如何修改默认的超时时？

OpenFeign默认支持Ribbon

YML文件里需要开启OpenFeign客户端超时控制

ribbon:
  ReadTimeout:  5000
  ConnectTimeout: 5000
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OpenFeign日志打印功能

是什么

日志级别

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;
    }
}
 
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YML文件里需要开启日志的Feign客户端

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