SpringBoot+Mybatis多模块(module)项目搭建教程

一、前言

最近公司项目准备开始重构,框架选定为SpringBoot+Mybatis,本篇主要记录了在IDEA中搭建SpringBoot多模块项目的过程。

1、开发工具及系统环境

  • IDE:IntelliJ IDEA 2018.2
  • 系统环境:mac OSX

2、项目目录结构

  • biz层:业务逻辑层
  • dao层:数据持久层
  • web层:请求处理层

二、搭建步骤

1、创建父工程

① IDEA 工具栏选择菜单 File -> New -> Project...

② 选择Spring Initializr,Initializr默认选择Default,点击Next

 ③ 填写输入框,点击Next

 

④ 这步不需要选择直接点Next

⑤ 点击Finish创建项目

⑥ 最终得到的项目目录结构如下

 ⑦ 删除无用的.mvn目录、src目录、mvnw及mvnw.cmd文件,最终只留.gitignore和pom.xml

2、创建子模块

① 选择项目根目录beta右键呼出菜单,选择New -> Module

② 选择Maven,点击Next

③ 填写ArifactId,点击Next

④ 修改Module name增加横杠提升可读性,点击Finish

⑤ 同理添加【beta-dao】、【beta-web】子模块,最终得到项目目录结构如下图

3、运行项目

① 在beta-web层创建com.yibao.beta.web包(注意:这是多层目录结构并非单个目录名,com >> yibao >> beta >> web)并添加入口类BetaWebApplication.java

package com.yibao.beta.web;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @author linjian
 * @date 2018/9/29
 */
@SpringBootApplication
public class BetaWebApplication { public static void main(String[] args) { SpringApplication.run(BetaWebApplication.class, args); } }

② 在com.yibao.beta.web包中添加controller目录并新建一个controller,添加test方法测试接口是否可以正常访问

package com.yibao.beta.web.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author linjian
 * @date 2018/9/29
 */
@RestController
@RequestMapping("demo")
public class DemoController {

    @GetMapping("test")
    public String test() {
        return "Hello World!";
    }
}

③ 运行BetaWebApplication类中的main方法启动项目,默认端口为8080,访问http://localhost:8080/demo/test得到如下效果

以上虽然项目能正常启动,但是模块间的依赖关系却还未添加,下面继续完善

4、配置模块间的依赖关系

各个子模块的依赖关系:biz层依赖dao层,web层依赖biz层

① 父pom文件中声明所有子模块依赖(dependencyManagement及dependencies的区别自行查阅文档)

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>com.yibao.beta</groupId>
            <artifactId>beta-biz</artifactId>
            <version>${beta.version}</version>
        </dependency>
        <dependency>
            <groupId>com.yibao.beta</groupId>
            <artifactId>beta-dao</artifactId>
            <version>${beta.version}</version>
        </dependency>
        <dependency>
            <groupId>com.yibao.beta</groupId>
            <artifactId>beta-web</artifactId>
            <version>${beta.version}</version>
        </dependency>
    </dependencies>
</dependencyManagement>

其中${beta.version}定义在properties标签中

② 在beta-web层中的pom文件中添加beta-biz依赖

<dependencies>
    <dependency>
        <groupId>com.yibao.beta</groupId>
        <artifactId>beta-biz</artifactId>
    </dependency>
</dependencies>

③ 在beta-biz层中的pom文件中添加beta-dao依赖

<dependencies>
    <dependency>
        <groupId>com.yibao.beta</groupId>
        <artifactId>beta-dao</artifactId>
    </dependency>
</dependencies>

5、web层调用biz层接口测试

① 在beta-biz层创建com.yibao.beta.biz包,添加service目录并在其中创建DemoService接口类

package com.yibao.beta.biz.service;

/**
 * @author linjian
 * @date 2018/9/29
 */
public interface DemoService {

    String test();
}
package com.yibao.beta.biz.service.impl;

import com.yibao.beta.biz.service.DemoService;
import org.springframework.stereotype.Service;

/**
 * @author linjian
 * @date 2018/9/29
 */
@Service
public class DemoServiceImpl implements DemoService {

    @Override
    public String test() {
        return "test";
    }
}

② DemoController通过@Autowired注解注入DemoService,修改DemoController的test方法使之调用DemoService的test方法,最终如下所示

package com.yibao.beta.web.controller;

import com.yibao.beta.biz.service.DemoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author linjian
 * @date 2018/9/29
 */
@RestController
@RequestMapping("demo")
public class DemoController {

    @Autowired
    private DemoService demoService;

    @GetMapping("test")
    public String test() {
        return demoService.test();
    }
}

③ 再次运行BetaWebApplication类中的main方法启动项目,发现如下报错

***************************
APPLICATION FAILED TO START
***************************

Description:

Field demoService in com.yibao.beta.web.controller.DemoController required a bean of type 'com.yibao.beta.biz.service.DemoService' that could not be found.


Action:

Consider defining a bean of type 'com.yibao.beta.biz.service.DemoService' in your configuration.

原因是找不到DemoService类,此时需要在BetaWebApplication入口类中增加包扫描,设置@SpringBootApplication注解中的scanBasePackages值为com.yibao.beta,最终如下所示

package com.yibao.beta.web;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @author linjian
 * @date 2018/9/29
 */
@SpringBootApplication(scanBasePackages = "com.yibao.beta")
@MapperScan("com.yibao.beta.dao.mapper")
public class BetaWebApplication {

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

设置完后重新运行main方法,项目正常启动,访问http://localhost:8080/demo/test得到如下效果

6、集成Mybatis

① 父pom文件中声明mybatis-spring-boot-starter及lombok依赖

dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.22</version>
        </dependency>
    </dependencies>
</dependencyManagement>

② 在beta-dao层中的pom文件中添加上述依赖

<dependencies>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
</dependencies>

③ 在beta-dao层创建com.yibao.beta.dao包,通过mybatis-genertaor工具生成dao层相关文件(DO、Mapper、xml),存放目录如下

④ applicatio.properties文件添加jdbc及mybatis相应配置项

spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://192.168.1.1/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = test
spring.datasource.password = 123456

mybatis.mapper-locations = classpath:mybatis/*.xml
mybatis.type-aliases-package = com.yibao.beta.dao.entity

⑤ DemoService通过@Autowired注解注入UserMapper,修改DemoService的test方法使之调用UserMapper的selectByPrimaryKey方法,最终如下所示

package com.yibao.beta.biz.service.impl;

import com.yibao.beta.biz.service.DemoService;
import com.yibao.beta.dao.entity.UserDO;
import com.yibao.beta.dao.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @author linjian
 * @date 2018/9/29
 */
@Service
public class DemoServiceImpl implements DemoService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public String test() {
        UserDO user = userMapper.selectByPrimaryKey(1);
        return user.toString();
    }
}

⑥ 再次运行BetaWebApplication类中的main方法启动项目,发现如下报错

APPLICATION FAILED TO START
***************************

Description:

Field userMapper in com.yibao.beta.biz.service.impl.DemoServiceImpl required a bean of type 'com.yibao.beta.dao.mapper.UserMapper' that could not be found.


Action:

Consider defining a bean of type 'com.yibao.beta.dao.mapper.UserMapper' in your configuration.

原因是找不到UserMapper类,此时需要在BetaWebApplication入口类中增加dao层包扫描,添加@MapperScan注解并设置其值为com.yibao.beta.dao.mapper,最终如下所示

package com.yibao.beta.web;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @author linjian
 * @date 2018/9/29
 */
@SpringBootApplication(scanBasePackages = "com.yibao.beta")
@MapperScan("com.yibao.beta.dao.mapper")
public class BetaWebApplication {

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

设置完后重新运行main方法,项目正常启动,访问http://localhost:8080/demo/test得到如下效果

至此,一个简单的SpringBoot+Mybatis多模块项目已经搭建完毕,我们也通过启动项目调用接口验证其正确性。

四、总结

一个层次分明的多模块工程结构不仅方便维护,而且有利于后续微服务化。在此结构的基础上还可以扩展common层(公共组件)、server层(如dubbo对外提供的服务)

此为项目重构的第一步,后续还会的框架中集成logback、disconf、redis、dubbo等组件

五、未提到的坑

在搭建过程中还遇到一个maven私服的问题,原因是公司内部的maven私服配置的中央仓库为阿里的远程仓库,它与maven自带的远程仓库相比有些jar包版本并不全,导致在搭建过程中好几次因为没拉到相应jar包导致项目启动不了。

posted @ 2018-09-29 15:49  枫本非凡  阅读(26986)  评论(7编辑  收藏