1. 整体类图

mybatis整体关键类图

2. 整体流程

2.1 代码

2.1.1 main类

public static void main(String[] args) {
        String resource = "mybatis-config.xml";
        InputStream inputStream =  Resources.getResourceAsStream(resource);
        SqlSession sqlSession  = new SqlSessionFactoryBuilder().build(inputStream);
        RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class);
        Role role = new Role();
        role.setRoleName("testName");
        role.setNote("testNote");
        roleMapper.insertRole(role);
        roleMapper.deleteRole(1L);
        sqlSession.commit();
    }

2.1.2 RoleMapper接口

public interface RoleMapper {
    public Role getRole(Long id);
    public int deleteRole(Long id);
    public int insertRole(Role role);
}

2.1.3 Role类（省去getter和setter方法）

public class Role {
    private Long id;
    private String roleName;
    private String note;
  // 省去getter和setter方法
}

2.1.4 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>
    <typeAliases>
        <typeAlias alias="role" type="com.yjk.mybatis.Role"/>
    </typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC">
                <property name="autoCommit" value="false"/>
            </transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/myfirstdb?characterEncoding=utf8&amp;useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="12345678"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="roleMapper.xml"/>
    </mappers>
</configuration>

2.1.5 roleMapper.xml

<?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="com.yjk.mybatis.RoleMapper">
    <select id="getRole" parameterType="long" resultType="role">
        select id,role_name as roleName,note from t_role where id = #{id}
    </select>
    <insert id="insertRole" parameterType="role">
        insert into t_role(role_name,note) values (#{roleName},#{note})
    </insert>
    <delete id="deleteRole" parameterType="long">
        delete from t_role where id = #{id}
    </delete>
</mapper>

2.2 构建sqlSession和getMapper方法对应的流程

构建sqlSession和getMapper方法对应的流程

2.3 对应Mapper接口中的方法执行流程

对应Mapper接口中方法执行流程

参考

mybatis源码：https://github.com/mybatis/mybatis-3.git