Springcloud-Rest微服务构建

1.1 总体介绍

1、项目会使用一个Dept部门模块做一个微服务通用案例
Consumer消费者（Client）通过REST调用Provider提供者（Server）提供的服务。

Maven的分包分模块架构

一个简单的Maven模块结构是这样的：
-- app-parent：一个父项目（app-parent）聚合很多子项目（app-util，app-dao，app-web...）
|-- pom.xml
|
|-- app-core
||----pom.xml
|
|-- app-web
||----pom.xml
......

一个父工程带着多个子Module子模块，SpringCloud父工程（Project）下初次带着3个子模块(Module)

• springcloud-api 【封装的整体pojo / 接口 / 公共配置等】。
• springcloud-provider-dept-8001【服务提供者】。
• springcloud-consumer-dept-80【服务消费者】

2、创建数据库db_springclound

-- 创建数据库
create database db_springclound1;

-- 使用数据库
use db_springclound1;

-- 创建员工表
create table dept(
	deptno bigint not null primary key auto_increment,
	dname varchar(60),
	db_source varchar(60)
);
-- 插入数据
insert into dept(dname,db_source) values('开发部',database());
insert into dept(dname,db_source) values('人事部',database());
insert into dept(dname,db_source) values('财务部',database());
insert into dept(dname,db_source) values('市场部',database());
insert into dept(dname,db_source) values('运维部',database());
insert into dept(dname,db_source) values('后勤部',database());

1.2 创建父工程

新建父工程Maven项目 springcloud-parent，切记Packageing是pom模式，倒入相关依赖。

springcloud-parent pom.xml

<?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>cn.guardwhy</groupId>
    <artifactId>springcloud-parent</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>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>
        <!-- spring-cloud的依赖 -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Hoxton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- spring-boot依赖 -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.2.1.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- 数据库 -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
            <!--数据源druid-->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.1.6</version>
            </dependency>
            <!-- mybatis-spring-boot启动器-->
            <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>${junit.version}</version>
            </dependency>
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

1.3创建api公共模块

新建springcloud-api模块

​

1、导入springcloud-api 的 pom.xml

<?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-parent</artifactId>
        <groupId>cn.guardwhy</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-api</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <!--当前Module需要到的jar包，按自己需求添加，如果父项目已经包含了，可以不用写版本号-->
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
</project>

2、编写部门实体类

注意: 实体类需要实例化

package cn.guardwhy.springcloud.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

@Data
@NoArgsConstructor
@AllArgsConstructor
// Dept实体类
public class Dept implements Serializable {
    // 主键
    private Long deptno;
    // 部门名称
    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，同一个信息被存到多个不同的数据库
    private String db_source;
}

1.4 创建provider模块

新建springcloud-provider-dept-8001模块

​

1、导入springcloud-provider-dept-8001的pom.xml

<?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-parent</artifactId>
        <groupId>cn.guardwhy</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

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

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!--引入自定义的模块，我们就可以使用这个模块中的类了-->
        <dependency>
            <groupId>cn.guardwhy</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <!--数据库连接-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- druid数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>
        <!-- mybatis-spring-boot启动器-->
        <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-test</artifactId>
        </dependency>
        <!-- spring-boot-devtools -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>
</project>

2、编辑 application.yml

server:
  port: 8001

# mybatis的配置
mybatis:
  type-aliases-package: cn.guardwhy.springcloud.pojo
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/cn/guardwhy/mapper/*.xml
  
#spring的相关配置
spring:
  application:
    name: springcloud-provider-dept
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource  # 数据源
    driver-class-name: org.gjt.mm.mysql.Driver   # mysql驱动
    url: jdbc:mysql://localhost:3306/db_springclound?useUnicode=true&characterEncoding=utf8&useSSL=false #数据库名称
    username: root
    password: root
    dbcp2:
      min-idle: 5  #数据库连接池的最小维持连接数
      initial-size: 5 #初始化连接数
      max-total: 5  #最大连接数
      max-wait-millis: 200 #等待连接获取的最大超时时间

3、编辑mybatis-config.xml文件

<?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>

4、编写部门的dao接口

package cn.guardwhy.springcloud.dao;

import cn.guardwhy.springcloud.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;
@Mapper
@Repository
public interface DeptDao {
    // 1.添加一个部门
    boolean addDept(Dept dept);
    // 2.根据id查询部门
    Dept queryById(Long id);
    // 3.查询所有的部门
    List<Dept> queryAll();
}

5、编写对应的DeptDaoMapper.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--
实体类的映射文件: namespace 指定接口的类全名
-->
<mapper namespace="cn.guardwhy.springcloud.dao.DeptDao">
    <!--1.添加一个部门-->
    <insert id="addDept" parameterType="Dept">
        insert into dept(dname,db_source) values (#{dname}, DATABASE())
    </insert>

    <!--2.根据id查询部门-->
    <select id="queryById" resultType="Dept" parameterType="Long">
        select deptno,dname,db_source from dept where deptno = #{deptno};
    </select>

    <!--3.查询所有部门-->
    <select id="queryAll" resultType="Dept">
        select * from dept;
    </select>
</mapper>

6、创建对应的Service服务层

package cn.guardwhy.springcloud.service;

import cn.guardwhy.springcloud.pojo.Dept;

import java.util.List;

public interface DeptService {
    // 1.添加一个部门
    boolean addDept(Dept dept);
    // 2.根据id查询部门
    Dept queryById(Long id);
    // 3.查询所有的部门
    List<Dept> queryAll();
}

7、ServiceImpl实现类

package cn.guardwhy.springcloud.service.impl;

import cn.guardwhy.springcloud.dao.DeptDao;
import cn.guardwhy.springcloud.pojo.Dept;
import cn.guardwhy.springcloud.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class DeptServiceImpl implements DeptService {
    // 1.自动注入
    @Autowired
    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();
    }
}

8、创建对应的DeptController

package cn.guardwhy.springcloud.controller;

import cn.guardwhy.springcloud.pojo.Dept;
import cn.guardwhy.springcloud.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 java.util.List;

// 提供Restful服务！！
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;

    @PostMapping("/dept/add")
    public boolean addDept(Dept dept){
        return deptService.addDept(dept);
    }

    @GetMapping("/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id){
        return deptService.queryById(id);
    }

    @PostMapping("/dept/list")
    public List<Dept> queryAll(){
        return deptService.queryAll();
    }
}

9、编写DeptProvider的主启动类

package cn.guardwhy.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DeptProvider8001 {
    public static void main(String[] args) {
        SpringApplication.run(DeptProvider8001.class, args);
    }
}

10、启动项目，查看执行结果。

​

1.5 创建consumer模块

新建springcloud-consumer-dept-80模块

​

1、导入相关依赖支持

<?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-parent</artifactId>
        <groupId>cn.guardwhy</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-consumer-dept-80</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!--实体类+web-->
        <dependency>
          <groupId>cn.guardwhy</groupId>
          <artifactId>springcloud-api</artifactId>
          <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--热部署-->
        <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>
</project>

2、application.yml

server:
  port: 80

3、创建一个ConfigBean配置类注入 RestTemplate

RestTemplate提供了多种便捷访问远程Http服务的方法，是一种简单便捷的访问restful服务模板类，是Spring提供的用于访问Rest服务的客户端模板工具集。

使用RestTemplate访问restful接口非常的简单(url，requsetMap，ResponseBean.class) 这三个参数分别代表REST请求地址，请求参数，Http响应转换被转换成的对象类型。

package cn.guardwhy.springcloud.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();
    }
}

4、创建对应的controller

package cn.guardwhy.springcloud.controller;

import cn.guardwhy.springcloud.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
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 {
    // RestTemplate: 直接调用就可以了,直接注册到Spring中
    //(url, 实体：map, Class<T> responseType)这三个参数分别代表REST请求地址，请求参数，Http响应转换被转换成的对象类型
    @Autowired
    private RestTemplate restTemplate; // 提供多种便捷访问远程http服务的方法,简单的Restful服务模板！！
    // 1.定义成常量
    private static final String REST_URL_PREFIX = "http://localhost:8001";

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

    @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);
    }
}

5、创建主启动类

package cn.guardwhy.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DeptConsumer80 {
    public static void main(String[] args) {
        SpringApplication.run(DeptConsumer80.class,args);
    }
}

6、分别启动provider模块和consumer模块，查看执行结果。