1.通过maven创建springboot项目

maven --> org.apache.maven.archetypes:maven-archetype-quickstart

若不使用springboot，则选择maven-archetype-webapp，以war包形式部署。

2. 引入springboot依赖包

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
</parent>
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
</dependency>

3.测试简单运行

@EnableAutoConfiguration   //SpringBoot自动化配置
public class App
{
    @RequestMapping("/")  
    public String home(){
        return "Hello World!";
    }
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
        SpringApplication.run(App.class,args);   //启动SpringBoot
    }
}

4.Mybatis 接入SpringBoot

引入依赖

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.3</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

添加插件

<plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.5</version>
                    <configuration>
                       <!--允许移动文件-->
                        <verbose>true</verbose>
                        <!--允许自动覆盖文件-->
                        <overwrite>true</overwrite>
                        <!--mybatis配置文件-->
                        <configurationFile>
                            src/main/resources/mybatisConfig-generator.xml
                        </configurationFile>
                    </configuration>
                    <executions>
                        <execution>
                            <id>mybatis generator</id>
                            <phase>package</phase>
                            <goals>
                                <goal>generate</goal>
                            </goals>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>8.0.13</version>
                        </dependency>
                        <dependency>
                            <groupId>org.mybatis.generator</groupId>
                            <artifactId>mybatis-generator-core</artifactId>
                            <version>1.3.5</version>
                        </dependency>
                    </dependencies>
                </plugin>

创建mybatisConfig-generator.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <context id="DB2Tables" targetRuntime="MyBatis3">
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://127.0.0.1:3306/***?useInformationSchema=true"
                        userId="***"
                        password="***">
        </jdbcConnection>
        <!-- 生成DataObject类存放位置 -->
        <javaModelGenerator targetPackage="com.***.dataobject" targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>
        <!-- 生成映射文件存放位置 -->
        <sqlMapGenerator targetPackage="mapping"  targetProject="src/main/resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>
        <!-- 生成Dao类存放位置 -->
        <!-- 客户端代码，生成易于使用的针对Model对象和XML配置文件的代码
              type="ANNOTATIONDMAPPER"，生成Java Model和基于注解的Mapper 对象
              type="MIXEDMAPPER",生成基于注解的Java Model和相应的Mapper对象
              type="XMLMAPPER",生成SQLMap XML 文件和独立的Mapper接口
         -->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.***.dao"  targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>
        <!--生成对应表及类名-->
        <table schema="***" tableName="user_info" domainObjectName="UserDO" enableCountByExample = "false"
               enableUpdateByExample = "false" enableDeleteByExample = "false"
               enableSelectByExample = "false"  selectByExampleQueryId = "false"></table>      
    </context>
</generatorConfiguration>

自动生成数据库Mybatis映射文件