MyBatis框架搭建与代码解读分析

<?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>
    <!--   MyBatis配置文件-->
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
    <!-- 为类配置别名-->
    <typeAliases>
        <!--<typeAlias type="com.kid.mybatispro.model.Admin" alias="Admin"></typeAlias>-->
        <package name="com.kid.mybatispro.model"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <!--type="POOLED" 使用数据库连接池功能-->
            <dataSource type="POOLED">
                <!-- 数据库连接的配置-->
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://127.0.0.1:3306/ssmdb?serverTimezone=Asia/Shanghai"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 注册映射文件-->
    <mappers>
        <mapper resource="mappers/AdminMapper.xml"></mapper>
    </mappers>
</configuration>

 create table admin(
   id int  primary key auto_increment,
   account varchar(20),
   password varchar(20),
   gender CHAR(1)
 )

package com.kid.mybatispro.dao;
import com.kid.mybatispro.model.Admin;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface AdminDao {
    //单个参数传递
    Admin findAdminById(int id);
    Admin findAdminByAccount(int id);
    //多个参数的传递
    Admin login(@Param("acc") String account, @Param("pass") String password);
    Admin login1(Admin admin);
    // 添加数据
    void insertAdmin(Admin admin);
    void deleteAdmin(int id);
    void updateAdmin(Admin admin);
    int findAdminCount();
    String findAdminId(String account);
    List<Admin> findAdmins();
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="接口的地址">
<select id="findAdminById" parameterType="int" resultType="com.ffyc.mybatis.model.Admin">
select * from admin where id = #{id} </select> </mapper>

    public static void main(String[] args) throws IOException {
        //MyBatis读取配置文件
        Reader reader = Resources.getResourceAsReader("mybatis.xml");
        //创建 SqlSessionFactory   负责创建SqlSession对象(连接数据库的会话对象,类似Connection)
        //SqlSessionFactory对象只需要创建一次，不需要销毁
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
        //创建SqlSession对象
        SqlSession sqlSession = sessionFactory.openSession();
        //创建接口的代理对象
        AdminDao adminDao = sqlSession.getMapper(AdminDao.class);
        Admin admin = adminDao.findAdminById(1); //让代理对象带我们巧用映射文件中与此接口中相同名称的方法
        System.out.println(admin);
    }