原创作者：田超凡（程序员田宝宝）
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Part 1 理论部分
1 为什么选择SpringCloud？
因为SpringCloud的出现，对微服务架构领域提供了非常大的帮助，SpringCloud实现了一套完整的微服务解决方案，不像其他框架只是解决了微服务中的某一类问题。SpringCloud提供了非常多的微服务解决方案，比如：
1 服务治理：阿里巴巴开源的Dubbo以及当当网再次基础上封装的DubboX，Eureka，Apache的Consul等
2 分布式配置中心：百度的disconf，Netflix的Arthaus，360的QConf，SpringCloud Config,携程的阿波罗Appolo等
3 分布式任务调度：XXL-Job,Elastic-Job,SpringCloudAlibaba ScheduleX等
4 分布式服务链路动态追踪：京东的hyra，SpringCloud Sleuth+Zipkin，SkyWalking等。
2 SpringCloud简介？
SpringCloud是一套基于SpringBoot基础之上开发的微服务框架，SpringCloud是一个提供了完整的微服务解决方案的框架，内容包括：负载均衡、RPC客户端、注册中心、服务保护、网关、配置中心、服务链路追踪、消息总线、API接口可视化管理工具等。
SpringCloud包含非常多的子项目，比如：
Ribbon
Feign/OpenFeign
Eureka
Hystrix
Zuul/Gateway
Config
Sleuth+Zipkin
Bus/AMQP
Swagger
3 什么是服务治理？
在传统的RPC远程服务调用过程中，服务和服务之间的依赖关系错综复杂，管理难度较大，所以需要通过服务治理来管理服务和服务之间的依赖关系，可以实现：服务调用、负载均衡、容灾等，从而实现服务注册和发现。
4 什么是服务注册和发现？
在服务注册和发现中，有一个注册中心，当服务器启动的时候，会将当前服务器自己的信息，比如：服务地址、通讯地址等通过别名的方式注册到注册中心中。
另一方（消费方或服务提供方），用该别名的方式从注册中心中获取实际的服务通讯地址，然后在本地实现RPC远程服务调用。
Part 2 实践部分
服务治理SpringCloud Eureka
搭建注册中心
常用注册中心框架
注册中心环境搭建
Maven依赖信息
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.1.RELEASE</version> </parent> <!-- 管理依赖 --> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Finchley.M7</version> <type>++pom++ </type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!--SpringCloud ++eureka++-server --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-++netflix++ -++eureka++-server</artifactId> </dependency> </dependencies> <!-- 注意： 这里必须要添加， 否者各种依赖有问题 --> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/libs-milestone\</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> |
application.yml
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ###服务端口号 server: port: 8100 ###eureka 基本信息配置 eureka: instance: ###注册到eurekaip地址 hostname: 127.0.0.1 client: ++serviceUrl++ : defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ ###因为自己是为注册中心，不需要自己注册自己 register-with-eureka: false ###因为自己是为注册中心，不需要检索服务 fetch-registry: false |
启动Eureka服务
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| @EnableEurekaServer @SpringBootApplication public class AppEureka { public static void main(String[] args) { SpringApplication.run(AppEureka.class , args); } } |
@EnableEurekaServer作用:开启eurekaServer
注册服务提供者
项目案例：实现用户服务（提供者）springcloud-2.0-member调用订单服务(消费者)springcloud-2.0-order
Maven依赖信息
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.1.RELEASE</version> </parent> <!-- 管理依赖 --> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Finchley.M7</version> <type>++pom++ </type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- SpringBoot整合Web组件 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- SpringBoot整合++eureka++客户端 --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-++netflix++ -++eureka++-client</artifactId> </dependency> </dependencies> <!-- 注意： 这里必须要添加， 否者各种依赖有问题 --> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/libs-milestone\</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> |
application.yml
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ###服务启动端口号 server: port: 8000 ###服务名称(服务注册到eureka名称) spring: application: name: app-ittcf-member ###服务注册到eureka地址 eureka: client: service-url: defaultZone: http://localhost:8100/eureka ###因为该应用为注册中心，不会注册自己 register-with-eureka: true ###是否需要从eureka上获取注册信息 fetch-registry: true |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
| @RestController public class MemberController { @RequestMapping("/getMember") public String getMember() { return "this is getMember"; } } |
启动用户服务
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| @SpringBootApplication @EnableEurekaClient public class AppMember { public static void main(String[] args) { SpringApplication.run(AppMember.class , args); } } |
可以看到用户服务成功注册到eureka服务上
服务消费者
Maven依赖信息
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.1.RELEASE</version> </parent> <!-- 管理依赖 --> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Finchley.M7</version> <type>++pom++ </type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- SpringBoot整合Web组件 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- SpringBoot整合++eureka++客户端 --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-++netflix++ -++eureka++-client</artifactId> </dependency> </dependencies> <!-- 注意： 这里必须要添加， 否者各种依赖有问题 --> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/libs-milestone\</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> |
application.yml配置
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ###服务启动端口号 server: port: 8001 ###服务名称(服务注册到eureka名称) spring: application: name: app-ittcf-order ###服务注册到eureka地址 eureka: client: service-url: defaultZone: http://localhost:8100/eureka ###因为该应用为注册中心，不会注册自己 register-with-eureka: true ###是否需要从eureka上获取注册信息 fetch-registry: true |
使用rest方式调用服务
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| @RestController public class OrderController { @Autowired private RestTemplate restTemplate; @RequestMapping("/getorder") public String getOrder() { // order 使用++rpc++ 远程调用技术 调用 用户服务 String memberUrl = "http://app-ittcf-member/getMember"; String result = restTemplate.getForObject(memberUrl, String.class ); System.out .println("用户服务调用订单服务,result:" + result); return result; } } |
启动消费者服务
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| @SpringBootApplication @EnableEurekaClient public class AppOrder { public static void main(String[] args) { SpringApplication.run(AppOrder.class , args); } @Bean @LoadBalanced RestTemplate restTemplate() { return new RestTemplate(); } } |
@LoadBalanced就能让这个RestTemplate在请求时拥有客户端负载均衡的能力
本文部分素材转载自蚂蚁课堂