<!--mysql-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <scope>runtime</scope>
    </dependency>
    <!-- mybatis依赖 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.4.6</version>
    </dependency>
    <!-- mybatis逆向工程依赖 -->
    <dependency>
      <groupId>org.mybatis.generator</groupId>
      <artifactId>mybatis-generator-core</artifactId>
      <version>1.3.7</version>
    </dependency>

3、创建逆向工程的配置文件 generatorConfig.xml

配置内容:

注意：配置文件中，各个元素标签出现的位置是有要求，位置不对会报错

<?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">
     <!-- 去除生成的注解 -->
     <commentGenerator>
        <property name="suppressAllComments" value="true"/>
     </commentGenerator>
     <!-- 数据库连接配置 -->
     <!-- 注意xml中不支持&，用&amp;代替 -->
     <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" 
     connectionURL="jdbc:mysql://rm-m5e130nm7h37n6v982o.mysql.rds.aliyuncs.com:3306/demo?useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=false&amp;serverTimezone=GMT%2B8"
     userId="xxxxx" password="xxxxxx"></jdbcConnection>
     
     <!-- 处理NUMERIC和DECIMAL类型的策略 -->
     <javaTypeResolver>
         <property name="forceBigDecimals" value="false" />
     </javaTypeResolver>
     
     <!-- 配置pojo生成的位置 -->
     <javaModelGenerator targetPackage="com.ycz.pojo"  targetProject="src/main/java">
        <property name="enableSubPackages" value="true" />
        <property name="trimStrings" value="true" />
     </javaModelGenerator>
     
     <!-- 配置sql映射文件的生成位置 -->
     <sqlMapGenerator targetPackage="com.ycz.mapper" targetProject="src/main/resources">
        <property name="enableSubPackages" value="true" />
        <property name="trimStrings" value="true" />        
     </sqlMapGenerator>
     
     <!-- 配置dao接口的生成位置 -->
     <javaClientGenerator type="XMLMAPPER" targetPackage="com.ycz.dao" 
     targetProject="src/main/java">
        <property name="enableSubPackages" value="true" />
        <property name="trimStrings" value="true" />     
     </javaClientGenerator>
     
     <!-- 指定逆向依据的数据表 -->
     <table tableName="person" domainObjectName="Person"></table>
   </context>
 </generatorConfiguration>

4、自动生成代码程序

一般写一个 text 方法就可以了，能运行就行

public class GeneratorTest {
    
    public static void main(String[] args) throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("src/main/resources/generatorConfig.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
        System.out.println("生成成功！");
    }

}

四、案例展示

一、建立数据表：user、book

二、改写配置文件：

1、数据库连接配置,指定自己的数据库

<!-- 数据库连接配置 -->
        <!-- 注意xml中不支持&，用&amp;代替 -->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/mybatisgenerator"
                        userId="root" password="">
<!--            在逆向生成时，除了会生成 User 类，还会生成一个继承 User 类的UserWithBLOBs 类。
                加入此注解避免生成类的UserWithBLOBs-->
            <property name="nullCatalogMeansCurrent" value="true" />
        </jdbcConnection>

2、配置pojo生成的位置

如果项目过多，保险起见指定为绝对路径

<javaModelGenerator 
targetPackage="org.example.pojo"
targetProject="G:/IDEA_MyProject/MabatisGenerator/src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
</javaModelGenerator>

3、配置sql映射文件的生成位置

<!-- 配置sql映射文件的生成位置 -->
        <sqlMapGenerator 
targetPackage="static.mapper"
targetProject="G:/IDEA_MyProject/MabatisGenerator/src/main/resources">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </sqlMapGenerator>

4、配置dao接口的生成位置

<!-- 配置dao接口的生成位置 -->
        <javaClientGenerator type="XMLMAPPER" 
targetPackage="org.example.dao"
targetProject="G:/IDEA_MyProject/MabatisGenerator/src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaClientGenerator>

5、指定逆向依据的数据表

<!-- 指定逆向依据的数据表 -->
        <table tableName="user" domainObjectName="User"></table>
        <table tableName="book" domainObjectName="Book"></table>

三、运行生成代码工具类

public class GeneratorTest {

    public static void main(String[] args) throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("G:/IDEA_MyProject/MabatisGenerator/src/main/resources/config/generatorConfig.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        myBatisGenerator.generate(null);
        System.out.println("生成成功！");
    }

}