Spring Cloud源码分析之Eureka第一章：准备工作

来源：互联网收集：自由互联发布时间：2022-07-05

欢迎访问我的GitHub 这里分类和汇总了欣宸的全部原创(含配套源码)：https://github.com/zq2599/blog_demos 大家好，从本章开始我们一起进入SpringCloud的源码世界，通过源码分析再结合实战，一起

欢迎访问我的GitHub

这里分类和汇总了欣宸的全部原创(含配套源码)：https://github.com/zq2599/blog_demos

大家好，从本章开始我们一起进入SpringCloud的源码世界，通过源码分析再结合实战，一起加深对SpringCloud体系的认识；

全文概览

本章是为后续的深度学习做准备工作，主要包含以下两部分：
开发三个简单应用，包括：注册中心、服务提供方、服务消费方，后续研究和实战都在这三个应用基础上进行；
下载后续分析研究中用到的源码，包括SpringCloud和Netflix的，版本和三个简单应用的一致；

版本列表

JDK：1.8；

spring boot：1.5.9.RELEASE；

spring cloud：Edgware.RELEASE；

应用简介

用列表简介本章要开发的三个应用：

应用名称作用占用端口 springclouddeepeureka 注册中心 8081 springclouddeepprovider 服务提供方 8082 springclouddeepconsumer 服务消费方 8083

实战源码下载

稍后会详细介绍这三个应用的开发和测试步骤，您也可以在github下载这三个应用的源码，地址和链接信息如下表所示：

名称链接备注项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页 git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址，https协议 git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址，ssh协议

这个git项目中有多个文件夹，本章源码分别在springclouddeepeureka、springclouddeepprovider、springclouddeepconsumer这三个文件夹下，如下图红框所示：

接下来准备demo工程吧，先从Eureka开始：
Eureka应用
基于maven创建一个spring boot的web应用springclouddeepeureka，pom.xml内容如下：

<?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> <groupId>com.bolingcavalry</groupId> <artifactId>springclouddeepeureka</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springclouddeepeureka</name> <description>Demo project for Eureka server</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.RELEASE</version> <relativePath/>  </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</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>Edgware.RELEASE</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>

resources目录下创建配置文件application.yml，内容如下：

server: port: 8081 eureka: client: registerWithEureka: false fetchRegistry: false serviceUrl: defaultZone: http://localhost:8081/eureka/

启动类SpringclouddeepeurekaApplication.java中，添加注解@EnableEurekaServer：

package com.bolingcavalry.springclouddeepeureka; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer; @SpringBootApplication @EnableEurekaServer public class SpringclouddeepeurekaApplication { public static void main(String[] args) { SpringApplication.run(SpringclouddeepeurekaApplication.class, args); } }

启动应用，浏览器访问8081端口，可见Eureka页面如下图：

至此，注册中心启动成功；

服务提供者

基于maven创建一个spring boot的web应用springclouddeepprovider，pom.xml内容如下：

<?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> <groupId>com.bolingcavalry</groupId> <artifactId>springclouddeepprovider</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springclouddeepprovider</name> <description>Demo project for Spring Cloud service provider</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.RELEASE</version> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.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-netflix-eureka-client</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>Edgware.RELEASE</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>

resources目录下创建配置文件application.yml，内容如下：

server: port: 8082 spring: application: name: springcloud-deep-provider eureka: client: serviceUrl: defaultZone: http://localhost:8081/eureka/ instance: prefer-ip-address: true

启动类SpringclouddeepproviderApplication.java中，添加注解@EnableDiscoveryClient：

package com.bolingcavalry.springclouddeepprovider; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; @SpringBootApplication @EnableDiscoveryClient public class SpringclouddeepproviderApplication { public static void main(String[] args) { SpringApplication.run(SpringclouddeepproviderApplication.class, args); } }

创建一个Controller类，用于提供http服务：

package com.bolingcavalry.springclouddeepprovider.Controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RestController; import java.text.SimpleDateFormat; import java.util.Date; /** * @Description : 提供普通的http服务 * @Author : za2599@gmail.com * @Date : 2018-08-18 18:25 */ @RestController public class HelloService { @GetMapping("hello/{name}") public String hello(@PathVariable String name){ return "Hello " + name + ", " + new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date()); } }

启动应用，浏览器访问路径：http://localhost:8082/hello/123 ，可收到server端响应如下图：

此时去刷新Eureka的页面，发现服务已经注册成功了，如下图：

至此，服务提供方应用开发完毕，最后一个是服务消费方springclouddeepconsumer；

服务消费方

基于maven创建一个spring boot的web应用springclouddeepconsumer，pom.xml内容如下：

<?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> <groupId>com.bolingcavalry</groupId> <artifactId>springclouddeepconsumer</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springclouddeepconsumer</name> <description>Demo project for Spring Cloud service consumer</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.RELEASE</version> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.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-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>

resources目录下创建配置文件application.yml，内容如下：

server: port: 8083 spring: application: name: springcloud-deep-consumer eureka: client: serviceUrl: defaultZone: http://localhost:8081/eureka/ instance: prefer-ip-address: true

启动类SpringclouddeepconsumerApplication.java中，添加注解@EnableDiscoveryClient：

package com.bolingcavalry.springclouddeepconsumer; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.client.loadbalancer.LoadBalanced; import org.springframework.context.annotation.Bean; import org.springframework.web.client.RestTemplate; @SpringBootApplication @EnableDiscoveryClient public class SpringclouddeepconsumerApplication { @Bean @LoadBalanced public RestTemplate restTemplate() { return new RestTemplate(); } public static void main(String[] args) { SpringApplication.run(SpringclouddeepconsumerApplication.class, args); } }

创建一个Controller类，用于提供http服务：

package com.bolingcavalry.springclouddeepconsumer.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.cloud.client.ServiceInstance; import org.springframework.cloud.client.loadbalancer.LoadBalancerClient; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; /** * @Description : 远程调用测试的 * @Author : qin_zhao@kingdee.com * @Date : 2018-08-18 19:10 */ @RestController public class ConsumerServiceController { @Autowired private RestTemplate restTemplate; @Autowired private LoadBalancerClient loadBalancerClient; @GetMapping("serviceinfo") public String serviceinfo(){ ServiceInstance serviceInstance = loadBalancerClient.choose("springcloud-deep-provider"); return null==serviceInstance ? "service not found" : serviceInstance.toString(); } @GetMapping("consume/{name}") public String consume(@PathVariable String name){ return this.restTemplate.getForObject("http://springcloud-deep-provider/hello/" + name, String.class); } }