一、SpringCloud是什么？

基于springboot的一种微服务生态，在springcloud当中，所有的服务都是模块化的，帮助开发者快速构建分布式系统，例如配置管理，服务注册与发现，熔断机制，智能路由，全局锁，分布式任务，集群构建等等。

SpringCloud解决的问题主要有四点：

1. 客户端如何访问服务
2. 服务于服务之间如何联系
3. 服务的注册与管理
4. 服务崩了，如何去处理

那么围绕这4个问题，就有了对应的解决方案，解决方案主要有三个。

• SpringCloud Netflix提供一站式的解决方案
• Dubbo，专注于服务通信这一块，zookeeper提供服务注册与发现
• springcloud Alibaba，也提供一站式的解决方案，慢慢在起步，以后用的企业应该会慢慢多起来。

听起来可能有点陌生，没关系，我会写系列文章把这些讲的明明白白。

那么今天讲解的主要是怎么构建一个简单的微服务，有一个服务的消费者，也有一个服务的注册者。

二、使用步骤

1.构建环境

父工程依赖

<?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.lhh</groupId><artifactId>springcloud</artifactId><version>1.0-SNAPSHOT</version><modules></modules><!-- 父工程改为pom --><packaging>pom</packaging><properties><junit.version>4.12</junit.version></properties><dependencyManagement><dependencies><!-- springcloud --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Hoxton.SR8</version><type>pom</type><scope>import</scope></dependency><!-- springboot --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>2.3.6.RELEASE</version><type>pom</type><scope>import</scope></dependency><!-- mysql --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.22</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.22</version></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.4</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.16</version></dependency><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.12</version></dependency></dependencies></dependencyManagement>
</project>

创建springcloud-api模块

springcloud-api模块导入依赖

<dependencies><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency>
</dependencies>

2.springcloud-provider-emp-8001

结构

pom.xml

 <!--引入实体类模块--><dependency><groupId>com.lhh</groupId><artifactId>springcloud-api</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.22</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jetty</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId></dependency>

application.yaml配置文件

server:port: 8001
mybatis:type-aliases-package: com.lhh.entitymapper-locations: classpath:mappers/*.xmlconfiguration:map-underscore-to-camel-case: truelog-impl: org.apache.ibatis.logging.stdout.StdOutImplspring:application:name: springcloud-provider-empdatasource:driver-class-name: com.cj.mysql.jdbc.Driver#    url: jdbc:mysql://localhost:3306/db01url: jdbc:mysql://localhost:3306/springcloud?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTCusername: root#    password: rootpassword: 123456#数据源类别type: com.alibaba.druid.pool.DruidDataSource

Empmapper.xml映射文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lhh.springcloudprovideremp8001.dao.EmpMapper"><select id="queryById" parameterType="Integer" resultType="Emp">select *from t_empwhere emp_id = #{empId}</select><select id="selectAllEmps" resultType="Emp">select *from t_emp</select>
</mapper>

启动类

package com.lhh.springcloudprovideremp8001;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
@MapperScan("com.lhh.springcloudprovideremp8001.dao")
public class SpringcloudProviderEmp8001Application {public static void main(String[] args) {SpringApplication.run(SpringcloudProviderEmp8001Application.class, args);}}

2.springcloud-consumer-emp-8001

 <!-- 引入实体类+web --><dependency><groupId>com.lhh</groupId><artifactId>springcloud-api</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId></dependency>

yaml配置文件

server:port: 80

消费者控制器

package com.lhh.springcloudconsumer.controller;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import java.util.List;@RestController
@RequestMapping("/consumer")
public class EmpConsumerController {//提供者的ip+端口private static final String REST_URL_PREFIX = "http://localhost:8001";@Autowiredprivate RestTemplate restTemplate;@GetMapping("/get/{empId}")public com.lhh.entity.Emp get(@PathVariable("empId") Integer empId) {return restTemplate.getForObject(REST_URL_PREFIX + "/provider/queryOne/" + empId, com.lhh.entity.Emp.class);}@GetMapping("/getAll")public List<com.lhh.entity.Emp> get() {return restTemplate.getForObject(REST_URL_PREFIX + "/provider/queryAll/", List.class);}
}

消费者启动类

package com.lhh.springcloudconsumer;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class SpringcloudConsumerApplication {public static void main(String[] args) {SpringApplication.run(SpringcloudConsumerApplication.class, args);}
}

总结

看完恭喜你，又知道了一点点!
你知道的越多，不知道的越多！
~感谢您的阅读，你的关注和评论，是对我学习的最大的支持，加油，陌生人，一起努力。