1，导包

<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.4.5</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.mybatis.generator/mybatis-generator-core -->
<dependency>
  <groupId>org.mybatis.generator</groupId>
  <artifactId>mybatis-generator-core</artifactId>
  <version>1.3.5</version>
</dependency>

2，配置文件
①，gengratorConfig.xml

<?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="testTables" targetRuntime="MyBatis3">
    <!-- 是否去掉注释 -->
    <commentGenerator>
        <property name="suppressAllComments" value="true" />
    </commentGenerator>

    <!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                    connectionURL="jdbc:mysql://127.0.0.1:3306/appmanager?useUnicode=true&amp;characterEncoding=utf-8"
                    userId="root"
                    password="12345678">
    </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>

    <!-- targetProject:生成POJO类的位置 -->
    <javaModelGenerator targetPackage="com.study.entity"
                        targetProject=".\src\main\java">
        <!-- enableSubPackages:是否让schema作为包的后缀 -->
        <property name="enableSubPackages" value="false" />
        <!-- 从数据库返回的值被清理前后的空格 -->
        <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!-- targetProject:mapper映射文件生成的位置 -->
    <sqlMapGenerator targetPackage="mapper"
                     targetProject=".\src\main\resources">
        <!-- enableSubPackages:是否让schema作为包的后缀 -->
        <property name="enableSubPackages" value="false" />
    </sqlMapGenerator>

    <!-- targetPackage：mapper接口生成的位置 -->
    <javaClientGenerator type="XMLMAPPER"
                         targetPackage="com.study.dao" targetProject=".\src\main\java">
        <!-- enableSubPackages:是否让schema作为包的后缀 -->
        <property name="enableSubPackages" value="false" />
    </javaClientGenerator>

    <!-- 指定数据库表 -->
    <!-- tableName:表名
    domainObjectName：生成java对象的类名
     -->
    <table tableName="user"
           domainObjectName="User"
           enableUpdateByExample="false"
           enableDeleteByExample="false">
    </table>
    <table tableName="app_version"
           domainObjectName="AppVersion"
           enableUpdateByExample="false"
           enableDeleteByExample="false">
    </table>
    <table tableName="app_info"
           domainObjectName="AppInfo"
           enableUpdateByExample="false"
           enableDeleteByExample="false">
    </table>
    <table tableName="app_category"
           domainObjectName="AppCategory"
           enableUpdateByExample="false"
           enableDeleteByExample="false">
    </table>
</context>

②，mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-config.dtd"> <!--dtd表示文档约束文档-->

<configuration>
<properties resource="db.properties">
</properties>

<settings>
   <!-- <setting name="logImpl" value="LOG4J"/>-->
    <!--<setting name="mapUnderscoreToCamelCase" value="true"/>-->
    <setting name="autoMappingBehavior" value="FULL"/>
    <setting name="cacheEnabled" value="true"/>
</settings>

<typeAliases>
    <package name="com.tao.entity"></package>
</typeAliases>

<environments default="development">
    <environment id="development">
        <!--事务管理器-->
        <transactionManager type="JDBC"/>
        <!--数据源-->
        <dataSource type="POOLED">
            <property name="driver" value="${jdbc.driverclass}"/>
            <property name="url" value="${jdbc.url}"/>
            <property name="username" value="${jdbc.username}"/>
            <property name="password" value="${jdbc.password}"/>
        </dataSource>
    </environment>
</environments>
<!--映射器-->
<mappers>
    <mapper resource="mapper/UserMapper.xml"/>
</mappers>
</configuration>

③，db.properties

jdbc.driverclass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///appmanager?useUnicode=true&characterEncoding=utf-8
jdbc.username=root
jdbc.password=12345678

3,逆向工程生成

package com.study;

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;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by Administrator on 2017/10/26.
 */
public class GeneratorSqlmap {
public void generator() throws Exception {
    List<String> warnings = new ArrayList<String>();
    boolean overwrite = true;
    // 指定逆向工程配置文件
    File configFile = new File("E:\\git\\mybatisgener\\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);
}

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

4，测试

package com.study;

import com.study.dao.UserMapper;
import com.study.entity.User;
import com.study.entity.UserExample;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;


/**
 * Created by Administrator on 2017/10/26.
 */
public class Mytest {

@Test
public void test1() throws IOException {
    InputStream resourceAsStream = Resources.getResourceAsStream("mybatis-config.xml");
    SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(resourceAsStream);
    SqlSession session = factory.openSession();
    //查询全部
    /* List<Object> objects = session.selectList("com.study.dao.UserMapper.selectByExample");
    System.out.println(objects);*/

    UserMapper mapper = session.getMapper(UserMapper.class);
    //条件查询
   /* UserExample userExample=new UserExample();
    UserExample.Criteria criteria = userExample.createCriteria();
    criteria.andUserNameEqualTo("admin").andUserPwdEqualTo("123456");
    List<User> users = mapper.selectByExample(userExample);
    System.out.println(users);*/

    //插入
    User user=new User("libai","132");
    int insert = mapper.insert(user);
    System.out.println(insert);


}

}