1.先将上面4个包放到lib文件夹下面

2.配置XML，放在SRC目录下

<?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>
  
  <!-- 配置ORACLE 驱动jar包路径.用了相对路径 -->
  <classPathEntry location="WebRoot/WEB-INF/lib/ojdbc7.jar" />

  <context id="yihaomen_mysql_tables" targetRuntime="MyBatis3">
  
    <!-- 为了防止生成的代码中有很多注释，比较难看，加入下面的配置控制 -->
    <commentGenerator>
      <property name="suppressAllComments" value="true" />
      <property name="suppressDate" value="true" />
    </commentGenerator>
    <!-- 注释控制完毕 -->
  
    <!-- 数据库连接, -->
    <jdbcConnection driverClass="oracle.jdbc.driver.OracleDriver"
        connectionURL="jdbc:oracle:thin:@152.19.5.181:1521/gldbpdb1"
        userId="Mybatis"
        password="mylove">
    </jdbcConnection>

    <javaTypeResolver >
      <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>
    
    <!-- 数据表对应的model 层 ,targetProject为自动生成后文件所放路径 -->
    <javaModelGenerator targetPackage="src.Model" targetProject="src">
      <property name="enableSubPackages" value="false" />
      <property name="trimStrings" value="true" />
    </javaModelGenerator>
    
    <!-- sql mapper 隐射配置文件 -->
    <sqlMapGenerator targetPackage="src.Map"  targetProject="src">
      <property name="enableSubPackages" value="false" />
    </sqlMapGenerator>
    
    <!-- 在ibatis2 中是dao层，但在mybatis3中，其实就是mapper接口 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="src.Client"  targetProject="src">
      <property name="enableSubPackages" value="false" />
    </javaClientGenerator>
    
    <!-- 要对那些数据表进行生成操作，必须要有一个. -->
    <table schema="mybatis" tableName="category" domainObjectName="Category" 
        enableCountByExample="false" enableUpdateByExample="false"
        enableDeleteByExample="false" enableSelectByExample="false"
        selectByExampleQueryId="false">     
    </table>

  </context>
</generatorConfiguration>

3.编写执行代码

package com.yihaomen.test;

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 GenMain {
	public static void main(String[] args) {
		List<String> warnings = new ArrayList<String>();
		boolean overwrite = true;
		String genCfg = "/mbgConfiguration.xml";
		File configFile = new File(GenMain.class.getResource(genCfg).getFile());
		ConfigurationParser cp = new ConfigurationParser(warnings);
		Configuration config = null;
		try {
			config = cp.parseConfiguration(configFile);
		} catch (IOException e) {
			e.printStackTrace();
		} catch (XMLParserException e) {
			e.printStackTrace();
		}
		DefaultShellCallback callback = new DefaultShellCallback(overwrite);
		MyBatisGenerator myBatisGenerator = null;
		try {
			myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
		} catch (InvalidConfigurationException e) {
			e.printStackTrace();
		}
		try {
			myBatisGenerator.generate(null);
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

4.执行Main方法即可自动生成所需要的文件