初识SpringCloud
Spring Cloud 是一套完整的微服务解决方案,基于 Spring Boot 框架,准确的说,它不是一个框架,而是一个大的容器,它将市面上较好的微服务框架集成进来,从而简化了开发者的代码量。
Spring Cloud 是什么?
Spring Cloud 是一系列框架的有序集合,它利用 Spring Boot 的开发便利性简化了分布式系统的开发,比如服务发现、服务网关、服务路由、链路追踪等。Spring Cloud 并不重复造轮子,而是将市面上开发得比较好的模块集成进去,进行封装,从而减少了各模块的开发成本。换句话说:Spring Cloud 提供了构建分布式系统所需的“全家桶”。
Spring Cloud 现状
目前,国内使用 Spring Cloud 技术的公司并不多见,不是因为 Spring Cloud 不好,主要原因有以下几点:
- Spring Cloud 中文文档较少,出现问题网上没有太多的解决方案。
- 国内创业型公司技术老大大多是阿里系员工,而阿里系多采用 Dubbo 来构建微服务架构。
- 大型公司基本都有自己的分布式解决方案,而中小型公司的架构很多用不上微服务,所以没有采用 Spring Cloud 的必要性。
但是,微服务架构是一个趋势,而 Spring Cloud 是微服务解决方案的佼佼者.
Spring Cloud 优缺点
优点
- 集大成者,Spring Cloud 包含了微服务架构的方方面面。
- 约定优于配置,基于注解,没有配置文件。
- 轻量级组件,Spring Cloud 整合的组件大多比较轻量级,且都是各自领域的佼佼者。
- 开发简便,Spring Cloud 对各个组件进行了大量的封装,从而简化了开发。
- 开发灵活,Spring Cloud 的组件都是解耦的,开发人员可以灵活按需选择组件。
缺点
- 项目结构复杂,每一个组件或者每一个服务都需要创建一个项目。
- 部署门槛高,项目部署需要配合 Docker 等容器技术进行集群部署,而要想深入了解 Docker,学习成本高。
Spring Cloud 的优势是显而易见的。学习 Spring Cloud 是一个不错的选择。
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Spring Cloud 和 Dubbo 对比
Dubbo 只是实现了服务治理,而 Spring Cloud 实现了微服务架构的方方面面,服务治理只是其中的一个方面。下面通过一张图对其进行比较:
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可以看出,Spring Cloud 比较全面,而 Dubbo 由于只实现了服务治理,需要集成其他模块,需要单独引入,增加了学习成本和集成成本。
项目结构
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父项目pom
<?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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.com.codingce</groupId>
<artifactId>springcloud</artifactId>
<version>1.0-SNAPSHOT</version>
<modules>
<module>springcloud-api</module>
<module>springcloud-provider-dept</module>
<module>springcloud-consumer-dept</module>
</modules>
<!--打包方式-->
<packaging>pom</packaging>
<!--统一配置 版本号-->
<properties>
<junit.version>4.12</junit.version>
<lombok.version>1.16.10</lombok.version>
<mysql.version>8.0.11</mysql.version>
<druid.version>1.1.10</druid.version>
<logbackcore.version>1.2.3</logbackcore.version>
</properties>
<dependencyManagement>
<dependencies>
<!-- springcloud的依赖 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!--springboot依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<scope>2.1.4.RELEASE</scope>
</dependency>
<!--连接数据库-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${druid.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<version>2.2.2.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jetty -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
<version>2.0.1.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.0.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<version>2.1.4.RELEASE</version>
</dependency>
</dependencies>
</dependencyManagement>
</project>
实体类
pom
<?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">
<parent>
<artifactId>springcloud</artifactId>
<groupId>cn.com.codingce</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>springcloud-api</artifactId>
<dependencies>
<!--当前module自己需要的依赖, 如果父依赖中已经配置了版本-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!--junit-->
<!-- <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>
</dependencies>
</project>
Dept
package cn.com.codingce.pojo;
import lombok.experimental.Accessors;
import java.io.Serializable;
/**
* @author xzMa
* Dept实体类 orm 类表关系映射
*/
@Accessors //链式写法
public class Dept implements Serializable {
private Long deptno;
private String dname;
private String db_source;
/**
* Dept dept = new Dept();
* dept.setDeptNo("").setDeptyName()..... 都行
*/
public Dept() {
}
public Dept(Long deptno, String dname, String db_source) {
this.deptno = deptno;
this.dname = dname;
this.db_source = db_source;
}
public Long getDeptno() {
return deptno;
}
public void setDeptno(Long deptno) {
this.deptno = deptno;
}
public String getDname() {
return dname;
}
public void setDname(String dname) {
this.dname = dname;
}
public String getDb_source() {
return db_source;
}
public void setDb_source(String db_source) {
this.db_source = db_source;
}
@Override
public String toString() {
return "Dept{" +
"deptno=" + deptno +
", dname='" + dname + '\'' +
", db_source='" + db_source + '\'' +
'}';
}
}
服务端
pom
<?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">
<parent>
<artifactId>springcloud</artifactId>
<groupId>cn.com.codingce</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>springcloud-provider-dept</artifactId>
<dependencies>
<!--我们需要拿到实体类, 所以要配置api -module-->
<dependency>
<groupId>cn.com.codingce</groupId>
<artifactId>springcloud-api</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!--junit-->
<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>
<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
<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-test</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- <!–jetty–>-->
<!-- <!– https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jetty –>-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
<!--热部署工具-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
</dependencies>
</project>
Controller
package cn.com.codingce.controller;
import cn.com.codingce.pojo.Dept;
import cn.com.codingce.service.DeptService;
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.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
import java.util.List;
/**
* @author xzMa
*
* 提供RestFul服务
*/
@RestController
public class DeptController {
@Resource
private DeptService deptService;
@PostMapping("/dept/add")
public boolean addDept(Dept dept) {
return deptService.addDept(dept);
}
@GetMapping("/dept/get/{id}")
public Dept queryBuId(@PathVariable("id") Long id) {
return deptService.queryById(id);
}
@GetMapping("/dept/list")
public List<Dept> queryAll() {
return deptService.queryAll();
}
}
DAO (mapper)
package cn.com.codingce.dao;
import cn.com.codingce.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface DeptDao {
public boolean addDept(Dept dept);
public Dept queryById(Long id);
public List<Dept> queryAll();
}
Mapper.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="cn.com.codingce.dao.DeptDao">
<insert id="addDept" parameterType="Dept">
insert into dept(dname, db_source) values (#{dname}, DATABASE())
</insert>
<select id="queryById" parameterType="Long" resultType="Dept">
select * from dept where deptno = #{deptno}
</select>
<select id="queryAll" resultType="Dept">
select * from dept
</select>
</mapper>
Service接口
package cn.com.codingce.service;
import cn.com.codingce.pojo.Dept;
import java.util.List;
public interface DeptService {
public boolean addDept(Dept dept);
public Dept queryById(Long id);
public List<Dept> queryAll();
}
Service实现类
package cn.com.codingce.service;
import cn.com.codingce.dao.DeptDao;
import cn.com.codingce.pojo.Dept;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;
@Service
public class DeptServiceImpl implements DeptService {
@Resource
private DeptDao deptDao;
@Override
public boolean addDept(Dept dept) {
return deptDao.addDept(dept);
}
@Override
public Dept queryById(Long id) {
return deptDao.queryById(id);
}
@Override
public List<Dept> queryAll() {
return deptDao.queryAll();
}
}
mybatis-config.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">
<!--核心配置文件-->
<configuration>
<!--开启二级缓存-->
<settings>
<setting name="cacheEnabled" value="true"/>
<setting name="logImpl" value="STDOUT_LOGGING"/>
</settings>
</configuration>
application.yml
server:
port: 8001
#mybatis配置
mybatis:
type-aliases-package: cn.com.codingce.pojo
config-location: classpath:mybatis/mybatis-config.xml
mapper-locations: classpath:mybatis/mapper/*.xml
# configuration:
# map-underscore-to-camel-case: true
# spring配置
spring:
application:
name: springcloud-provider-dept
datasource:
type: com.alibaba.druid.pool.DruidDataSource # 数据源 德鲁伊
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://cdb-q9atzwrq.bj.tencentcdb.com:10167/db01?useSSL=true
username: root
password: 123456
客户端
pom
<?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">
<parent>
<artifactId>springcloud</artifactId>
<groupId>cn.com.codingce</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>springcloud-consumer-dept</artifactId>
<dependencies>
<!--我们需要拿到实体类, 所以要配置api -module-->
<dependency>
<groupId>cn.com.codingce</groupId>
<artifactId>springcloud-api</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!--热部署工具-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
配置文件
package cn.com.codingce.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
@Configuration
public class ConfigBean { //configuration -- spring applicationContext.xml
@Bean
public RestTemplate getRestTemplate() {
return new RestTemplate();
}
}
Controller
package cn.com.codingce.controller;
import cn.com.codingce.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
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
public class DeptConsumerController {
// 理解消费者, 不应该有service层
//RestFul风格
//(url, 实体: Map classs<T> responseType)
@Autowired
private RestTemplate restTemplate; //提供多种便捷访问远程http服务的方法
private static final String REST_URL_PREFIX = "http://localhost:8001";
@RequestMapping("/consumer/dept/add")
public boolean add(Dept dept) {
return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
}
//http://localhost:8001/dept/list
@RequestMapping("/consumer/dept/get/{id}")
public Dept get(@PathVariable("id") Long id) {
return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class );
}
@RequestMapping("/consumer/dept/list")
public List<Dept> list() {
return restTemplate.getForObject(REST_URL_PREFIX + "/dept/list" , List.class );
}
}
application.yml
server:
port: 80