微服务SpringCloud开弓之OpenFeign服务接口调用「七」

1、概述

• OpenFeign是什么

  官网地址

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

GitHub

Feign和OpenFeign两者区别

2、OpenFeign使用步骤

• 接口+注解

  微服务调用接口+@FeignClient

• 新建cloud-consumer-feign-order80

  Feign在消费端使用
  

• POM

     <dependencies>
          <!--openfeign-->
          <dependency>
              <groupId>org.springframework.cloud</groupId>
              <artifactId>spring-cloud-starter-openfeign</artifactId>
          </dependency>
          <!--eureka client-->
          <dependency>
              <groupId>org.springframework.cloud</groupId>
              <artifactId>spring-cloud-starter-netflix-eureka-server</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>
          <!--监控-->
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-actuator</artifactId>
          </dependency>
          <!--热部署-->
          <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>
  

• YML

  server:
    port: 80
  eureka:
    client:
      register-with-eureka: false
  #      检索服务选项，当设置为True(默认值)时，会进行服务检索,注册中心不负责检索服务。
  #    fetch-registry: true
  
      service-url:
        defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka
  

• 主启动

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

• 业务类

  1、业务逻辑接口+@FeignClient配置调用provider服务

  新建PaymentFeignService接口并新增注解@FeignClient

  @Component
  @FeignClient(value = "CLOUD-PROVIDER-SERVICE")
  public interface PaymentFeignService {
  
      @PostMapping(value = "/payment/create")
      CommonResult<Payment> create(@RequestBody Payment payment);
  
      @GetMapping(value = "/payment/get/{id}")
      CommonResult<Payment> getPaymentById(@PathVariable("id") Long id);
  }
  
  

  2、控制层Controller

  @RestController
  @Slf4j
  public class OrderFeignController {
  
  
      @Resource
      private PaymentFeignService paymentFeignService;
  
      @PostMapping(value = "/consumer/payment/create")
      public  CommonResult<Payment> create(@RequestBody Payment payment){
         return paymentFeignService.create(payment);
      }
  
      @GetMapping(value = "/consumer/payment/get/{id}")
      public CommonResult getPaymentById(@PathVariable("id") Long id) {
          return paymentFeignService.getPaymentById(id);
      }
  
  }
  
  

• 测试

Feign自带负载均衡配置项

• 小结
  

3、OpenFeign超时控制

• 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

  ​ PaymentController

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

  2、服务消费方80添加超时方法

  ​ PaymentFeignService

   @GetMapping(value = "/payment/feign/timeout")
      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、报错

  http://localhost/consumer/payment/feign/timeout 延迟访问

  http://localhost:8001/payment/feign/timeout报错

• OpenFeign默认等待1秒钟,超过后报错
  

OpenFeign默认支持Ribbon

YML文件里需要开启OpenFeign客户端超时控制

ribbon:
  # 指的是建立连接所用的时间,适用于网络状态正常的情况下,两端连接所用的时间
  ReadTimeout: 5000
  # 指的是建立连接后从服务器读取到可用资源所用的时间
  ConnectTimeout: 5000

4、OpenFeign日志打印功能

• 日志级别

• 配置日志been

  @Configuration
  public class FeignConfig {
  
      /**
       * feignClient配置日志级别
       *
       * @return
       */
      @Bean
      public Logger.Level feignLoggerLevel() {
          // 请求和响应的头信息,请求和响应的正文及元数据
          return Logger.Level.FULL;
      }
  }
   
  

• YML文件里需要开启日志的Feign客户端

logging:
  level:
    # feign日志以什么级别监控哪个接口
    com.atguigu.springcloud.service.PaymentFeignService: debug

• 后台日志查看