springcon [SpringCloud教程]6. OpenFeign远程接口调用

【springcon [SpringCloud教程]6. OpenFeign远程接口调用】OpenFeign是声明式方式定义Web服务的客户端(说白了就是将原有的url请求调用转化为本地方法调用一样方便快捷)，并可通过集成Ribbon或Eureka实现负载均衡。

SpringCloud教程合集: https://www.cnblogs.com/spzmmd/tag/微服务教程/
案例项目地址: https://gitee.com/spzmmd/spring-cloud-demo

集成

在SpringCloud案例项目里建立新模块 ms-consumer-eureka-openfeign，并在父pom里声明，该模块pom.xml如下

<?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"><modelVersion>4.0.0</modelVersion><parent><groupId>com.spz.demo</groupId><artifactId>spring-cloud-demo</artifactId><version>1.0-SNAPSHOT</version></parent><artifactId>ms-consumer-eureka-openfeign</artifactId><packaging>jar</packaging><description>消费者模块 - 使用Eureka注册中心 - 使用OpenFeign客户端</description><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-client</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency><dependency><groupId>com.spz.demo</groupId><artifactId>api-common</artifactId><version>${project.version}</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><executions><execution><goals><goal>repackage</goal></goals></execution></executions><configuration><excludes><exclude><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></exclude></excludes></configuration></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>1.8</source><target>1.8</target></configuration></plugin></plugins><resources><resource><directory>src/main/resources</directory><filtering>true</filtering></resource></resources></build></project>

application.properties 配置如下

server.port=7001# Eurekaeureka.client.register-with-eureka=falseeureka.client.service-url.defaultZone=http://eureka6001:6001/eureka,http://eureka6002:6002/eureka,http://eureka6003:6003/eureka# Feign 日志级别logging.level.com.spz.demo.scloud.consumer.openfeign.service.IEurekaProviderService=debug# Feign 超时配置openfeign.connectTimeoutMs=1000openfeign.readTimeoutMs=5000

配置类OpenFeignConfiguration.java

package com.spz.demo.scloud.consumer.openfeign.config;import com.netflix.ribbon.Ribbon;import feign.Logger;import feign.Request;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;/** * OpenFeign 配置 * @author spzmmd * @createTime 2021/04/12 */@Configurationpublic class OpenFeignConfiguration {/*** 连接超时* 单位: ms*/@Value("${openfeign.connectTimeoutMs}")private int connectTimeoutMs;/*** 读取超时* 单位: ms*/@Value("${openfeign.readTimeoutMs}")private int readTimeoutMs;/*** 配置超时时间* @return*/@Beanpublic Request.Options options() {return new Request.Options(connectTimeoutMs, readTimeoutMs);}/*** 配置OpenFeign输出什么日志，方便调试* @return*/@Beanpublic Logger.Level feignLoggerLevel() {return Logger.Level.FULL;}}

启动类 ConsumerOpenFeignApp.java

package com.spz.demo.scloud.consumer.openfeign;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;import org.springframework.cloud.openfeign.EnableFeignClients;@EnableFeignClients@SpringBootApplicationpublic class ConsumerOpenFeignApp {public static void main(String[] args) {SpringApplication.run(ConsumerOpenFeignApp.class, args);}}

通过OpenFeign来实现微服务接口调用的方法是，将接口调用声明为一个个接口方法，如下代码

package com.spz.demo.scloud.consumer.openfeign.service;import com.spz.demo.scloud.common.core.bean.RestBean;import com.spz.demo.scloud.consumer.openfeign.config.OpenFeignConfiguration;import org.springframework.cloud.openfeign.FeignClient;import org.springframework.stereotype.Component;import org.springframework.web.bind.annotation.GetMapping;/** * Eureka 服务提供者 接口 * 用于配置 Feign 接口 * @author spzmmd * @createTime 2021/04/12 */@Component@FeignClient(value = "https://tazarkount.com/read/MS-PROVIDER", configuration = OpenFeignConfiguration.class)public interface IEurekaProviderService {@GetMapping(value = "https://tazarkount.com/projectInfo")public RestBean projectInfo();}

测试用的控制器

package com.spz.demo.scloud.consumer.openfeign.controller;import com.spz.demo.scloud.common.core.bean.RestBean;import com.spz.demo.scloud.common.service.AppService;import com.spz.demo.scloud.consumer.openfeign.service.IEurekaProviderService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;/** * 测试 openFeign * @author spzmmd * @createTime 2021/04/12 */@RestController@RequestMapping("/openFeign")public class OpenFeignTestController {// 使用OpenFeign，实现以接口调用的方式来进行网络请求@Autowiredprivate IEurekaProviderService eurekaProviderService;/*** 服务远程调用测试 - 使用 openFeign* @return*/@RequestMapping("/projectInfo")public RestBean appServiceProjectInfo(){RestBean restBean = eurekaProviderService.projectInfo();return restBean;}}

运行时，需要启动eureka-server(用于服务注册发现) 和两个ms-provider节点，用于测试OpenFeign方式调用微服务接口，而后启动ms-consumer-eureka-openfeign模块，不断访问如下地址:

http://localhost:7001/openFeign/projectInfo正常应该分别返回两个服务的端口号(OpenFeign默认支持负载均衡)

{"code": 2000,"message": "MS-PROVIDER:8001: (基于Eureka注册中心)","data": null}{"code": 2000,"message": "MS-PROVIDER:8002: (基于Eureka注册中心)","data": null}

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