1.准备配置文件

<?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>
    <!--数据库驱动,最好不要有中文字符,不然会找不到-->
    <classPathEntry location="D:/mysql-connector-java-5.1.40-bin.jar" />
    <context id="cosmetic"   targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接地址账号密码-->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/cosmetic" userId="root" password="0000">
        </jdbcConnection>
        <!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver"
            connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:orcl" 
            userId="scott"
            password="0000">
        </jdbcConnection> -->
         <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL 和 
            NUMERIC 类型解析为java.math.BigDecimal -->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!--生成pojo类存放位置-->
        <javaModelGenerator targetPackage="cn.pojo" targetProject="src">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!--生成映射文件mapper接口存放位置-->
        <sqlMapGenerator targetPackage="cn.dao" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!--生成mapper接口、mapper.xml类存放位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="cn.dao" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!--生成对应表及类名,需要记住的一点是逆向工程无法生成关联关系,只能生成单表操作-->
        <table  tableName="adminuser"   domainObjectName="User" />
        <table tableName="messageboard"  domainObjectName="Messageboard" />
        <table tableName="picture" domainObjectName="Picture"></table>
        <table tableName="product" domainObjectName="Product"></table>
        <table tableName="tourist" domainObjectName="Tourist"></table>
        <table tableName="type" domainObjectName="Type"></table>
    </context>
</generatorConfiguration>

2.下载jar包,大家如果找不到,可以去maven repository去下载: 

mybatis-generator-core-1.3.2.jar

3.编写java程序代码，在开发文档首页,粘贴一下就好了

package cn.test;

import java.io.File;
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.internal.DefaultShellCallback;

public class MybatisGen {
	public static void generator() throws Exception {
		List<String> warnings = new ArrayList<String>();
		boolean overwrite = true;
		// 项目根路径不要有中文,我的有中文,所以使用绝对路径
		File configFile = new File("D:/Program Files (x86)/MyEclipseWorkSpace/makeups/config/db.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);
	}

	public static void main(String[] args) {
		try {
			generator();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}