SpringCloud之服务注册与发现Spring Cloud Eureka实例代码
作者:smartdt
一、Spring Cloud简介
Spring Cloud是一个基千SpringBoot实现的微服务架构开发 工具。它为微服务架构中涉及的 配置管理、服务治理、 断路器、 智能路由、微代理、 控制总线、 全局锁、 决策竞选、分布式会话和集群状态管理等操作提供了一种简单的开发方式。
Spring Cloud包含了多个子项目(针对分布式系统中涉及的多个不同开源产品,还可能会新增),如下所述。
Spring Cloud Config: 配置管理工具、Spring Cloud Netflix: 核心组件、Spring Cloud Bus: 事件、消息总线等等。
二、Spring Cloud Eureka
Spring Cloud Eureka 是 Spring Cloud Netflix 微服务套件中的一部分, 它基于 NetflixEureka 做了二次封装, 主要负责完成微服务架构中的服务治理功能。 Spring Cloud 通过为Eureka 增加了 Spring Boot 风格的自动化配置,我们只需通过简单引入依赖和注解配置就能让 Spring Boot 构建的微服务应用轻松地与 Eureka 服务治理体系进行整合。
服务治理可以说是微服务架构中最为核心和基础的模块, 它主要用来实现各个微服务实例的自动化注册与发现。
三、实例
(1)工具:IntelliJ IDEA
(2)新建一个空项目
(3)新建一个Eureka Server,Module,名为:eurekaserver
工程右键->创建Module-> 选择spring initialir ->填好项目名,下一步->,如图选择Eureka Server:
(3-1)pom.xml
<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.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency>
(3-2)application.yml
server: port: 5555 eureka: instance: hostname: localhost client: registerWithEureka: false fetchRegistry: false serviceUrl: defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
备注:eureka.client.register-with-eureka: 由于该应用为注册中心,所以设置为 false, 代表不向注册中心注册自己。
eureka.client.fetch-registry: 由于注册中心的职责就是维护服务实例,它并不需要去检索服务, 所以也设置为 false。
(3-3)入口类
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer; @EnableEurekaServer @SpringBootApplication public class EurekaserverApplication { public static void main(String[] args) { SpringApplication.run(EurekaserverApplication.class, args); } }
(3-4)启动测试
在完成了上面的配置后,启动应用并访问 http://localhost:5555/。可以看到如下图所示的 Eureka 信息面板, 其中 Instances currently registered with Eureka 栏是空的, 说明该注册中心还没有注册任何服务。
(4)注册服务提供者在完成了服务注册中心的搭建之后,接下来我们尝试将一个既有的 Spring Boot 应用加入 Emeka 的服务治理体系中去。
(5)再新建一个Eureka Client,Module,名为:helloserver,这个helloserver作为eurekaserver的子model
(6)改造父model和子model的pom配置(6-1)eurekaserver的pom.xml配置:
<packaging>pom</packaging> <modules> <module>../helloserver</module> </modules>
(6-2)eurekaserver的全部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.example</groupId> <artifactId>demoeurekaserver</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> <modules> <module>../helloserver</module> </modules> <name>eurekaserver</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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.RELEASE</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.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>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
(6-3)helloserver的pom.xml配置:
<parent> <groupId>com.example</groupId> <artifactId>demoeurekaserver</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../eurekaserver/pom.xml</relativePath> </parent>
(6-4)helloserver的全部pom.xml配置:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>com.example</groupId> <artifactId>demoeurekaserver</artifactId> <version>0.0.1-SNAPSHOT</version> <relativePath>../eurekaserver/pom.xml</relativePath> </parent> <artifactId>helloserver</artifactId> <packaging>jar</packaging> <name>helloserver</name> <description>Demo project for Spring Boot</description> <properties> <start-class>com.example.helloserver.HelloserverApplication</start-class> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${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>
(6-5)helloserver的application.yml配置:
server: port: 5556 spring: application: name: helloserver eureka: client: serviceUrl: defaultZone: http://localhost:5555/eureka/
(6-6)helloserver的启动类:
@EnableEurekaServer @SpringBootApplication @RestController public class HelloserverApplication { private final Logger log = (Logger) LoggerFactory.getLogger(HelloserverApplication.class); @Autowired private DiscoveryClient client; @RequestMapping(name = "/hello", method = RequestMethod.GET) public String index() { ServiceInstance instance = client.getLocalServiceInstance(); log.info("/hello, host:" + instance.getHost() + ",service_id:" + instance.getServiceId()); return "Hello SpringCloud~"; } public static void main(String[] args) { SpringApplication.run(HelloserverApplication.class, args); } }
(7)分别启动eurekaserver和helloserver,并测试:
(7-1)访问eurekaserver:(可以很清楚的看到HELLOSERVER信息)
(7-2)访问helloserver:
(7-3)查看helloserver控制台信息:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。