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。
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：
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
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
