1.概述

OpenFeign是什麼

能幹嘛

Feign和OpenFeign兩者區別

2.OpenFeign使用步驟

<?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>springcloud2020</artifactId>
        <groupId>com.chl.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-consumer-feign-order80</artifactId>

    <!--openfeign-->
    <dependencies>
        <!--openfeign的依賴-->
        <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.chl.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>1.0-SNAPSHOT</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>
 

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

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

@Component
@FeignClient("CLOUD-PAYMENT-SERVICE") //對應的提供方的服務名
public interface PaymentFeignService {

    //要呼叫提供方的對應介面url  用呼叫本地的service方式呼叫 遠端的服務
    @GetMapping("/payment/get/{id}")
    public CommonResult get(@PathVariable("id")Long id);
}
 

@RestController
@Slf4j
public class OrderFeignController {

    @Autowired
    private PaymentFeignService paymentFeignService;

    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult get(@PathVariable("id")Long id){
       return paymentFeignService.get(id);
    }
}

3.OpenFeign超時控制

超時設定，故意設定超時演示出錯情況

  /**
     * 故意寫的服務提供方吃力業務要3秒，用於測試feign的超時問題
     * @return
     */
    @GetMapping(value = "/payment/feign/timeout")
    public String paymentFeignTimeout(){
        try { TimeUnit.SECONDS.sleep(3); }catch (Exception e) {e.printStackTrace();}
        return serverPort;
    }

//測試feigin的超時問題
    @GetMapping(value = "/payment/feign/timeout")
    public String paymentFeignTimeout();

/**
     * 測試feigin的超時問題
     * @return
     */
    @GetMapping(value = "/consumer/payment/feign/timeout")
    public String paymentFeignTimeout(){
        return paymentFeignService.paymentFeignTimeout();
    }

原因說明

OpenFeign預設支援Ribbon

超時設定

ribbon:
  ReadTimeout:  5000 #請求連線的超時時間 5秒
  ConnectTimeout: 5000 #請求處理的超時時間 5秒

4.OpenFeign日誌列印功能

是什麼

日誌級別

配置日誌bean

@Configuration
public class FeignConfig {

    @Bean
    Logger.Level feignLoggerLevel(){
        return Logger.Level.FULL;
    }
}

YML檔案裡需要開啟日誌的Feign客戶端

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