SpringCloud 入门

Posted 2020-11-17 思考与践行

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1. 入门概述

SpringBoot专注于快速方便的开发单个个体微服务;
SpringCloud:关注全局的微服务协调治理框架,它将SpringBoot开发的一个个单体微服务整合并管理起来,
为各个微服务之间提供配置管理,服务发现,断路器,路由,微代理,事件总线,全局锁,决策竞选,分布式会话等等集成服务;

1.1 Dubbo和SpringCloud比较

Dubbo服务调用方式:RPC
SpringCloud服务调用方式:REST API

2. SpringCloud 之 Hello World

2.1 创建整体父工程Project(microservicecloud)

主要是定义POM文件,将后续各个子模块公用的jar包等统一提取出来,类似一个抽象父类;

// pom.xml

<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.noodles.springcloud</groupId>
  <artifactId>microservicecloud</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>


  <properties>
  	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  	<maven.compiler.source>1.8</maven.compiler.source>
  	<maven.compiler.target>1.8</maven.compiler.target>
  	<junit.version>4.12</junit.version>
  	<log4j.version>1.2.17</log4j.version>
  	<lombok.version>1.16.18</lombok.version>
  </properties>


  <dependencyManagement>
  	<dependencies>
  		<dependency>
  			<groupId>org.springframework.cloud</groupId>
  			<artifactId>spring-cloud-dependencies</artifactId>
  			<version>Dalston.SR1</version>
  			<type>pom</type>
  			<scope>import</scope>
  		</dependency>
  		<dependency>
  			<groupId>org.springframework.boot</groupId>
  			<artifactId>spring-boot-dependencies</artifactId>
  			<version>1.5.9.RELEASE</version>
  			<type>pom</type>
  			<scope>import</scope>
  		</dependency>
  		<dependency>
  			<groupId>mysql</groupId>
  			<artifactId>mysql-connector-java</artifactId>
  			<version>5.0.4</version>
  		</dependency>
  		<dependency>
  			<groupId>com.alibaba</groupId>
  			<artifactId>druid</artifactId>
  			<version>1.0.31</version>
  		</dependency>
  		<dependency>
  			<groupId>org.mybatis.spring.boot</groupId>
  			<artifactId>mybatis-spring-boot-starter</artifactId>
  			<version>1.3.0</version>
  		</dependency>
  		<dependency>
  			<groupId>ch.qos.logback</groupId>
  			<artifactId>logback-core</artifactId>
  			<version>1.2.3</version>
  		</dependency>
  		<dependency>
  			<groupId>junit</groupId>
  			<artifactId>junit</artifactId>
  			<version>${junit.version}</version>
  			<scope>test</scope>
  		</dependency>
  		<dependency>
  			<groupId>log4j</groupId>
  			<artifactId>log4j</artifactId>
  			<version>${log4j.version}</version>
  		</dependency>
  	</dependencies>
  </dependencyManagement>
</project>

2.2 创建公共子模块Module(microservicecloud-api)

// pom.xml
<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.noodles.springcloud</groupId>
    <artifactId>microservicecloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>

  <artifactId>microservicecloud-api</artifactId>

  <dependencies>
  	<!-- 当前Module需要用到的jar包,按自己需要添加,如果父类已经包含了,可以不要写版本号 -->
  	<dependency>
  		<groupId>org.projectlombok</groupId>
  		<artifactId>lombok</artifactId>
  	</dependency>
  </dependencies>
</project>


// com.noodles.springcloud.entities
@SuppressWarnings("serial")
@AllArgsConstructor
@NoArgsConstructor
@Data
@Accessors(chain=true)
public class Dept implements Serializable{
    private Long deptno;
    private String dname;
    // 来自哪个数据库,因为微服务架构可以一个服务对应一个数据库,
    // 同一个信息被存储到不同数据库
    private String db_source;

    // 第一种方式:
    // 无参和全参构造函数
    // getter,setter和toString 方法

    // 第二种方式: 使用lombok,使用注解
    // Eclipse 需要安装lombok插件
}


// mvn clean install 后给其他模块引用,达到通用目的;
// 即需要用到部门实体的话,不用每个工程都定义一份,直接引用本模块即可;

2.3 部门微服务提供者Module(microservicecloud-provider-dept-8001)

// pom.xml
<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.noodles.springcloud</groupId>
    <artifactId>microservicecloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>

  <artifactId>microservicecloud-provider-dept-8001</artifactId>

  <dependencies>
  	<dependency>
  		<groupId>com.noodles.springcloud</groupId>
  		<artifactId>microservicecloud-api</artifactId>
  		<version>${project.version}</version>
  	</dependency>
  	<dependency>
  		<groupId>junit</groupId>
  		<artifactId>junit</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>mysql</groupId>
  		<artifactId>mysql-connector-java</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>com.alibaba</groupId>
  		<artifactId>druid</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>ch.qos.logback</groupId>
  		<artifactId>logback-core</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-jetty</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-test</artifactId>
  	</dependency>
  	<!-- 修改后立即生效,热部署 -->
  	<dependency>
  		<groupId>org.springframework</groupId>
  		<artifactId>springloaded</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>org.springframework.boot</groupId>
  		<artifactId>spring-boot-devtools</artifactId>
  	</dependency>
  </dependencies>
</project>


// src/main/resources/application.yml
server:
  port: 8081

mybatis:
   config-location: classpath:mybatis/mybatis.cfg.xml      # mybatis配置文件所在路径
   type-aliases-package: com.noodles.springcloud.entities  # 所有Entity别名类所在包
   mapper-locations:
   - classpath:mybatis/mapper/**/*.xml

spring:
   application:
     name: microservicecloud-dept
   datasource:
     type: com.alibaba.druid.pool.DruidDataSource           # 当前数据源操作类型
     driver-class-name: org.gjt.mm.mysql.Driver             # mysql驱动包
     url: jdbc:mysql://localhost:3306/cloudDB01             # 数据库名称
     username: root
     password: root
     dbcp2:
       min-idle: 5
       initial-size: 5
       max-total: 5
       max-wait-millis: 200


// src/main/sources/mybatis/mybatis.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
	<settings>
		<!-- 开启二级缓存 -->
		<setting name="cacheEnabled" value="true"/>
	</settings>
</configuration>


// com.noodles.springcloud.dao
@Mapper
public interface DeptDao {
	public boolean addDept(Dept dept);

	public Dept findById(Long id);

	public List<Dept> findAll();
}

// src/main/sources/mybatis/mapper/DeptMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.noodles.springcloud.dao.DeptDao">

	<select id="findById" resultType="Dept" parameterType="Long">
		select deptno,dname,db_source from dept where deptno=#{deptno};
	</select>
	<select id="findAll" resultType="Dept">
		select deptno,dname,db_source from dept;
	</select>
	<insert id="addDept" parameterType="Dept">
	INSERT INTO dept(dname,db_source) VALUES(#{dname},DATABASE());
	</insert>

</mapper>


// DeptService部门服务接口
public interface DeptService {
	public boolean add(Dept dept);
	public Dept get(Long id);
	public List<Dept> list();
}


// DeptServiceImpl部门服务接口实现类
@Service
public class DeptServiceImpl implements DeptService{

	@Autowired
	private DeptDao deptDao;

	@Override
	public boolean add(Dept dept) {

		return deptDao.addDept(dept);
	}

	@Override
	public Dept get(Long id) {

		return deptDao.findById(id);
	}

	@Override
	public List<Dept> list() {

		return dptDao.findAll();
	}
}


//DeptController部门微服务提供者REST
@RestController
public class DeptController {

	@Autowired
	private DeptService deptService;

	@RequestMapping(value="/dept/add",method=RequestMethod.POST)
	public boolean add(@RequestBody Dept dept) {
		return deptService.add(dept);
	}

	@RequestMapping(value="/dept/get/{id}",method=RequestMethod.GET)
	public Dept get(@PathVariable("id") Long id) {
		return deptService.get(id);
	}

	@RequestMapping(value="/dept/list",method=RequestMethod.GET)
	public List<Dept> get() {
		return deptService.list();
	}
}


// DeptProvider8001_App主动启动类DeptProvider8001_App
@SpringBootApplication
public class DeptProvider8001_App {

	public static void main(String[] args) {
		SpringApplication.run(DeptProvider8001_App.class, args);
	}
}

2.4 部门微服务消费者Module(microservicecloud-consumer-dept-80)

// pom.xml
<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.noodles.springcloud</groupId>
    <artifactId>microservicecloud</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>

  <artifactId>microservicecloud-consumer-dept-80</artifactId>
  <description>部门微服务消费者</description>

  <dependencies>
  	<dependency>
  		<groupId>com.noodles.springcloud</groupId>
  		<artifactId>microservicecloud-api</artifactId>
  		<version>${project.version}</version>
  	</dependency>
  	<dependency>
  		<groupId>org.springframework.boot</groupId>
  		<artifactId>spring-boot-starter-web</artifactId>
  	</dependency>
  	<!-- 修改后立即生效,热部署 -->
  	<dependency>
  		<groupId>org.springframework</groupId>
  		<artifactId>springloaded</artifactId>
  	</dependency>
  	<dependency>
  		<groupId>org.springframework.boot</groupId>
  		<artifactId>spring-boot-devtools</artifactId>
  	</dependency>
  </dependencies>
</project>


// application.yml
server:
  port: 8082


// com.noodles.springcloud.cfgbeans
// ConfigBean 类(作用类似Spring里面的applicationContext.xml写入的注入Bean)
@Configuration
public class ConfigBean{
    @Bean
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}


// 新建DeptController_Consumer部门微服务消费者REST
// com.noodles.springcloud.controller
@RestController
public class DeptController_Consumer {

	private static final String REST_URL_PREFIX = "http://localhost:8081";

	/**
	 * 使用restTemplate访问restful接口:
	 * (url, requestMap, ResponseBean.class)这三个参数分别代表:
	 * REST请求地址,请求参数,HTTP响应被转换成的对象类型
	 */
	@Autowired
	private RestTemplate restTemplate;

	@RequestMapping(value="/consumer/dept/add")
	public boolean add(Dept dept) {
		return restTemplate.postForObject(REST_URL_PREFIX+"/dept/add", dept, Boolean.class);
	}

	@RequestMapping(value="/consumer/dept/get/{id}")
	public Dept get(@PathVariable("id") Long id) {
		return restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/"+id, Dept.class);
	}

	@SuppressWarnings("unchecked")
	@RequestMapping(value="/consumer/dept/list")
	public List<Dept> list() {
		return restTemplate.getForObject(REST_URL_PREFIX+"/dept/list", List.class);
	}
}


// com.noodles.springcloud
// DeptConsumer80_App 主启动类
@SpringBootApplication
public class DeptConsumer80_App {

	public static void main(String[] args) {

		SpringApplication.run(DeptConsumer80_App.class, args);
	}

}

// 测试:
// 访问:
// http://localhost:8082/consumer/dept/get/2
// http://localhost:8082/consumer/dept/list

参考资料:

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