导入三个包

Mysql mysql-connector-java-5.1.39-bin.jar
Mybatis mybatis-3.4.6.jar
打印日志 log4j-1.2.17.jar

Mybatis可用xml配置文件

首先创建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">
<configuration>

    <!-- 引入properties文件,里面存放driver，url，username，password的数据库信息 -->
    <properties resource="mysql.properties"/>

    <!-- 为类设置别名，否则在mapper配置中要输入完整包名 -->
    <typeAliases>
        <typeAlias alias="customer" type="com.shpun.entity.Customer"/>
    </typeAliases>

    <!-- 配置数据库信息 -->
    <environments default="testCustoemr">
        <environment id="testCustomer">
            <transactionManager type="JDBC"></transactionManager>
            <!-- 使用数据库连接池 -->
            <dataSource type="POOLED">      
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

</configuration>

通过mybatis-config.xml构建SqlSessionFactory

package com.shpun.utils;
public class SqlSessionFactoryUtils {

    private final static Class<SqlSessionFactoryUtils> LOCK = SqlSessionFactoryUtils.class;

    private static SqlSessionFactory sqlSessionFactory;

    private SqlSessionFactoryUtils(){}

    public static SqlSessionFactory getSqlSessionFactory(){
        synchronized (LOCK){
            if(sqlSessionFactory != null){
                return sqlSessionFactory;
            }

            String resource = "mybatis-config.xml";
            InputStream inputStream;
            try {
                // 读取 mybatis-config.xml 配置文件
                inputStream = Resources.getResourceAsStream(resource);
                // 根据配置文件构建 SqlSessionFactory
                sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            }catch (Exception e){
                e.printStackTrace();
                return null;
            }
            return sqlSessionFactory;
        }
    }
    // 提供获取 SqlSession 的方法
    public static SqlSession openSqlSession(){
        if(sqlSessionFactory == null){
            getSqlSessionFactory();
        }
        return sqlSessionFactory.openSession();
    }
}

创建JavaBean Customer

package com.shpun.entity;
public class Customer {
    private String id;
    private String name;
    private String gender;
    private String birthday;
    private String tel;
    private String email;
    private String introduction;
    /*getter setter*/
}

定义映射器 需要Java接口和xml文件

创建CustomerMapper接口

package com.shpun.mapper;
public interface CustomerMapper {
    int insertCustomer(Customer customer);
    int deleteCustomer(String id);
    int updateCustomer(Customer customer);
    Customer selectCustomer(String id);
    List<Customer> selectAllCustomer();
}

创建CustomerMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<!-- 使Mybatis能找到该接口 -->
<mapper namespace="com.shpun.mapper.CustomerMapper">

    <!-- 默认自动映射，即表column与JavaBean的变量名要一致，可通过加as实现 -->

    <!-- parameterType="customer" 传入的参数为customer，customer在mysql-config.xml中已经定义了别名
        若未定义，应完整包名com.shpun.entity.Customer
     -->
    <!--  useGeneratedKeys="true" 使用Statement的getGeneratedKeys()进行主键回填，获取新插入的主键
          keyProperty="id" 为填入 JavaBean 中的哪个属性 Customer 中为 id
    -->
    <insert id="insertCustomer" parameterType="customer" useGeneratedKeys="true" keyProperty="id">
        insert into customers (name,gender,birthday,tel,email,introduction) value (#{name},#{gender},#{birthday},#{tel},#{email},#{introduction})
    </insert>

    <!-- parameterType="string" 为系统定义别名 Java类型为 String -->
    <delete id="deleteCustomer" parameterType="string">
        delete from customers where id=#{id}
    </delete>

    <update id="updateCustomer" parameterType="customer">
        update customers set name=#{name},gender=#{gender},birthday=#{birthday},tel=#{tel},email=#{email},introduction=#{introduction} where id=#{id}
    </update>

    <select id="selectCustomer" parameterType="string" resultType="customer">
        select * from customers where id=#{id}
    </select>

    <select id="selectAllCustomer" resultType="customer">
        select * from customers
    </select>


    <!-- 定义结果集映射规则等 用于Select
          默认是自动映射，即表column与JavaBean属性名要一致，也可在select中用as修改，
          使用默认，则select中为resultType="customer"
          若要使用下列resuleMap，替换select中resultType="customer"为resultMap="customerMap"
   
    <resultMap id="customerMap" type="customer">
        <id property="id" column="id"></id>
        <result property="name" column="name"></result>
        <result property="gender" column="gender"></result>
        <result property="birthday" column="birthday"></result>
        <result property="tel" column="tel"></result>
        <result property="email" column="email"></result>
        <result property="introduction" column="introduction"></result>
    </resultMap>
    -->
</mapper>

创建完映射一定一定一定要到mybatis-config.xml中添加

    <!-- 配置完映射xml，需要在mybatis-config.xml中添加 -->
    <mappers>
        <mapper resource="com/shpun/mapper/CustomerMapper.xml"/>
    <!--
          或包名引入 则自动扫描
       <package name="com/shpun/mapper"/>
    -->
    </mappers>

mybatis-config.xml->工具类->JavaBean->Mapper的接口和xml文件

测试使用

        Logger log = Logger.getLogger(TestMybatis.class);    
        SqlSession sqlSession = null;

        try{

            // 获取SqlSeesion
            sqlSession = SqlSessionFactoryUtils.openSqlSession();
            // 获取Mapper
            CustomerMapper customerMapper = sqlSession.getMapper(CustomerMapper.class);
  
            log.info(customerMapper.selectAllCustomer());

          /* 增删改需要添加
            sqlSession.commit();
          */
        }catch (Exception e){
            e.printStackTrace();
          /* 增删改需要添加
            sqlSession.rollback();
          */
        }finally {
          // 使用完要关闭
            if(sqlSession != null){
                sqlSession.close();
            }
        }

使用log4j需要添加log4j.properties

log4j.rootLogger=DEBUG,stdout
log4j.logger.org.mybatis=DEBUG
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p %d %c: %m%n