7.dao层接口与接口xml配置

public interface UserDao {
    List<User> getUserList();

    User getUser(int id);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.bm.dao.UserDao">
    <select id="getUserList" resultType="com.bm.pojo.User">
        select * from user
    </select>

    <select id="getUser" resultType="com.bm.pojo.User">
        select * from user where id = #{id}
    </select>
</mapper>