【SpringCloud】第二篇: 服务消费者(rest+ribbon)
前言:
必需学会SpringBoot基础知识
简介:
spring cloud 为开发人员提供了快速构建分布式系统的一些工具,包括配置管理、服务发现、断路器、路由、微代理、事件总线、全局锁、决策竞选、分布式会话等等。它运行环境简单,可以在开发人员的电脑上跑。
工具:
JDK8
apache-maven-3.5.2
IntelliJ IDEA 2017.3 x64
ribbon 简介
Ribbon is a client side load balancer which gives you a lot of control over the behaviour of HTTP and TCP clients. Feign already uses Ribbon, so if you are using @FeignClient then this section also applies. —–摘自官网
ribbon是一个负载均衡客户端,可以很好的控制htt和tcp的一些行为。Feign默认集成了ribbon。
一、准备工作
本篇是基于第一篇为基础, 首先, 启动 eureka-server:8761 和 eureka-client 项目的dev:8762, pro:8763 分别启动两个实例. 临时搭建一个小集群, 然后访问 127.0.0.1:8761 查看 eureka-client 两个实例是否启动了.
二、新建服务消费者 (eureka-ribbon)
2.1 pom.xml
<?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> <groupId>com.lwc</groupId> <artifactId>eureka-ribbon</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>eureka-ribbon</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.10.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-cloud.version>Edgware.SR2</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka-server</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-ribbon</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
2.2 通过 application.yml 跳转 application-dev.yml 配置程序名, 端口 和指定注册中心 如下:
spring: application: name: eureka-ribbon profiles: active: ${@profileActiv@:dev}
eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ server: port: 8764
2.3 通过@EnableDiscoveryClient向服务中心注册, 并且利用ioc注入@Bean, 然后通过@LoadBalanced表明restTemplate()开启负载均衡功能; 如下:
package com.lwc; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; /** * @author Eddie */ @EnableDiscoveryClient @SpringBootApplication public class EurekaRibbonApplication { public static void main(String[] args) { SpringApplication.run(EurekaRibbonApplication.class, args); } }
package com.lwc.template; import org.springframework.cloud.client.loadbalancer.LoadBalanced; import org.springframework.context.annotation.Bean; import org.springframework.stereotype.Component; import org.springframework.web.client.RestTemplate; /** * @author eddie.lee * @Package com.lwc.template * @ClassName RestConfig * @description * @date created in 2018-03-26 19:54 * @modified by */ @Component public class RestConfig { @Bean @LoadBalanced public RestTemplate restTemplate(){ return new RestTemplate(); } }
2.4 创建服务层测试使用, ribbonService() 里面url使用了eureka-client服务器名称代替127.0.0.1:8762; 如下:
package com.lwc.service; /** * @author eddie.lee * @Package com.lwc.service * @ClassName RibbonService * @description * @date created in 2018-03-26 19:55 * @modified by */ public interface RibbonService { String ribbonService(String name); }
package com.lwc.service.impl; import com.lwc.service.RibbonService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import org.springframework.web.client.RestTemplate; /** * @author eddie.lee * @Package com.lwc.service.impl * @ClassName RibbonServiceImpl * @description * @date created in 2018-03-26 19:57 * @modified by */ @Service public class RibbonServiceImpl implements RibbonService { @Autowired private RestTemplate restTemplate; @Override public String ribbonService(String name) { final String url = "http://eureka-client/eureka/client?name=" + name; return restTemplate.getForObject(url, String.class); } }
2.5 创建 controller 作为调用测试服务层使用; 如下:
package com.lwc.controller; import com.lwc.service.RibbonService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; /** * @author eddie.lee * @Package com.lwc.controller * @ClassName RibbonControler * @description 服务消费者 * @date created in 2018-03-26 20:02 * @modified by */ @RestController @RequestMapping("/eureka") public class RibbonControler { @Autowired private RibbonService ribbonService; @GetMapping("/ribbon") public String Ribbon(@RequestParam String name) { return ribbonService.ribbonService(name); } }
新手解析: ribbon相当于 请求ribbon的时候会随机访问eureka-client:8762 和 eureka-client:8763,
为什么? 如果一台eureka-client:8762挂了, 还有eureka-client:8763, 保证服务正常使用;
eureka-ribbon
http://localhost:8764/eureka/ribbon?name=eddie
标签
2-1
源码下载
https://github.com/eddie-code/SpringCloudDemo#springclouddemo