使用之前先在pom檔案中加上如下依賴：

<!-- 匯入Mysql資料庫連結jar包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.30</version>
        </dependency>
<!-- mybatis自動生成實體類 -->
 

        <dependency>
            <groupId>org.mybatis.generator</groupId>
            <artifactId>mybatis-generator-core</artifactId>
            <version>1.3.2</version>
        </dependency>

這兩個依賴是程式能夠自動生成實體類的基礎，必不可少。下面是生成步驟：

①在當前專案中建立一個generator.xml檔案，這個檔名字可以自取，也不能太隨意

②generator.xml配置如下內容

<?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>
    <!-- <properties resource="db.properties" /> -->
 

    <classPathEntry location="E:\Developments Tools\mysql-connector-java-5.1.33.jar" />
    <context id="mysql2Beans" targetRuntime="MyBatis3">
        <commentGenerator>
            <!-- 刪除程式碼中帶有 程式碼生成器的註釋資訊 -->
            <property name="suppressAllComments" value="false" />
            <!-- 是否去除自動生成的註釋 true：是 ： false:否 -->
            <property name="suppressDate" value="true" />
        </commentGenerator>

        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
            connectionURL="你的資料庫連線" 
            userId="登入名"
            password="密碼" />

        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

         <!-- 生成模型的包名和位置--> 
        <javaModelGenerator targetPackage="com.lyt.usermanage.pojo" targetProject="E:\ConvertBean">
            <property name="enableSubPackages" value="true" /> 
            <property name="trimStrings" value="true" /> 
        </javaModelGenerator>

        <sqlMapGenerator targetPackage="com.lyt.usermanage.mapper" targetProject="E:\ConvertBean">
            <property name="enableSubPackages" value="true" /> 
        </sqlMapGenerator>

        <javaClientGenerator targetPackage="com.lyt.usermanage.dao" targetProject="E:\ConvertBean" type="XMLMAPPER">
            <property name="enableSubPackages" value="true" /> 
        </javaClientGenerator>


        <!-- 要生成的表 tableName是資料庫中的表名或檢視名 domainObjectName是實體類名-->    
        <!--無論欄位是什麼型別，生成的類屬性都是varchar -->
        <!-- <table schema="btupayprod" tableName="T_INFO_MARKETING_CFG" enableSelectByExample="false" 
            enableDeleteByExample="false" enableCountByExample="false" enableUpdateByExample="fasle"> 
            </table> -->
        <!-- <columnOverride column="AFTER_AMT" jdbcType="VARCHAR" /> -->
        <!-- <table schema="btupayprod" tableName="t_log_online_payment" enableSelectByExample="false" 
            enableDeleteByExample="false" enableCountByExample="false" enableUpdateByExample="fasle"> 
            無論欄位是什麼型別，生成的類屬性都是varchar <columnOverride column="AFTER_AMT" jdbcType="VARCHAR" 
            /> </table> -->

        <table schema="test" tableName="user_third" domainObjectName="LytUserThird" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" 
           enableSelectByExample="false" selectByExampleQueryId="false"></table>

        <table schema="test" tableName="user_stat" domainObjectName="LytUserStat" enableCountByExample="false" enableUpdateByExample="false"    
           enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false">    
        </table>    

        <table schema="test" tableName="user_relation" domainObjectName="LytUserRelation" enableCountByExample="false" enableUpdateByExample="false"    
           enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false">    
        </table>  

       </context> 
</generatorConfiguration>

具體配置標籤請跳轉：Mybatis Generator詳解
注意：table有多少寫多少，這是個手動活

③反轉生成的兩種方式

方式一：編寫工具類執行

package com.lyt.usermanage.utils;

import java.io.File;    
import java.io.IOException;    
import java.sql.SQLException;    
import java.util.ArrayList;    
import java.util.List;    

import org.mybatis.generator.api.MyBatisGenerator;    
import org.mybatis.generator.config.Configuration;    
import org.mybatis.generator.config.xml.ConfigurationParser;    
import org.mybatis.generator.exception.InvalidConfigurationException;    
import org.mybatis.generator.exception.XMLParserException;    
import org.mybatis.generator.internal.DefaultShellCallback;    

public class MyBatisGeneratorUtils {    

    public static void main(String[] args) {    
        try {    
            System.out.println("start generator ...");    
            List<String> warnings = new ArrayList<String>();    
            boolean overwrite = true;    
            File configFile = new File(MyBatisGeneratorUtils.class.getResource("/mybatis/generator.xml").getFile());    
            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("end generator!");    
        } catch (IOException e) {    
            e.printStackTrace();    
        } catch (XMLParserException e) {    
            e.printStackTrace();    
        } catch (InvalidConfigurationException e) {    
            e.printStackTrace();    
        } catch (SQLException e) {    
            e.printStackTrace();    
        } catch (InterruptedException e) {    
            e.printStackTrace();    
        }    
    }    

}  

方式二：配置bat檔案執行

執行完成後你就可以到你配置的生成檔案儲存路徑去找檔案了