Mybatis学习（九）mybatis原始dao接口与dao实现的开发。

来源：互联网发布：怎么提高记忆知乎编辑：程序博客网时间：2024/05/18 16:35

在我们ssh的框架开发中一般会有dao层的分层，在这儿我们也开发出一个用于比较。

在目录机构框架中加入dao层

cn.bj.mybatis

|---model

|---dao

|---impl

类分别为IUserDao.java、UserDaoImpl.java

IUserDao.java

package cn.bj.mybatis.dao;import cn.bj.mybatis.model.User;public interface IUserDao {//根据用户ID查询用户信息public User selectUser(int id);//增加用户信息public void addUser(User user);//删除用户信息public void deleteUser(int id);//修改用户信息public void updateUser(User user);}

UserDaoImpl.java

package cn.bj.mybatis.dao.impl;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import cn.bj.mybatis.dao.IUserDao;import cn.bj.mybatis.model.User;public class UserDaoImpl implements IUserDao{//需要向dao实现类中注入sqlSessionFactoryprivate SqlSessionFactory sqlSessionFactory;//在这里用构造方法注入public UserDaoImpl(SqlSessionFactory sqlSessionFactory){this.sqlSessionFactory = sqlSessionFactory;}@Overridepublic User selectUser(int id) {SqlSession session = sqlSessionFactory.openSession();User user = session.selectOne("cn.bj.mybatis.models.UserMapper.selectUser", id);session.close();return user;}@Overridepublic void addUser(User user) {SqlSession session = sqlSessionFactory.openSession();session.insert("cn.bj.mybatis.models.UserMapper.addUser", user);session.commit();session.close();}@Overridepublic void deleteUser(int id) {SqlSession session = sqlSessionFactory.openSession();session.delete("cn.bj.mybatis.models.UserMapper.deleteUser", id);session.commit();session.close();}@Overridepublic void updateUser(User user) {SqlSession session = sqlSessionFactory.openSession();session.update("cn.bj.mybatis.models.UserMapper.updateUser", user);session.commit();session.close();}}

User.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="cn.bj.mybatis.models.UserMapper"> --> <mapper namespace="cn.bj.mybatis.models.UserMapper"> <select id="getUserOrders" parameterType="int" resultMap="resultUserOrderList">       select t_user.id,t_user.username,t_user.age,t_order.id o_id,t_order.orderName from t_user,t_order where t_user.id=t_order.userid and t_user.id=#{id}    </select>   <resultMap type="Order" id="resultUserOrderList">        <id property="id" column="o_id"/>        <result property="orderName" column="orderName"/>         <association property="user" javaType="User">            <id property="id" column="id" />            <result property="name" column="name" />            <result property="age" column="age" />        </association>           </resultMap>  <!-- 查询数据 -->  <select id="selectUser"  resultType="User">    select * from t_user where id = #{id}  </select>  <!-- 增加数据 -->  <insert id="addUser" parameterType="User" useGeneratedKeys="true" keyProperty="id">  insert into t_user(username,age) values(#{username},#{age})  </insert>  <!-- 修改数据 -->  <update id="updateUser" parameterType="User">  update t_user set username=#{username},age=#{age} where id=#{id}  </update>  <!-- 删除数据 -->  <delete id="deleteUser" parameterType="int">  delete from t_user where id = #{id}  </delete></mapper>

Mybatistest.java

package cn.bj.mybatis.test;import java.io.IOException;import java.io.InputStream;import java.util.List;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 cn.bj.mybatis.dao.IUserDao;import cn.bj.mybatis.dao.impl.UserDaoImpl;import cn.bj.mybatis.model.IUserOperation;import cn.bj.mybatis.model.Order;import cn.bj.mybatis.model.User;public class MybatisTest {public static void main(String[] args){SqlSessionFactory sqlSessionFactory = null;SqlSession session = null;String resource = "Configuration.xml";InputStream inputStream;try {inputStream = Resources.getResourceAsStream(resource);sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);IUserDao userDao = new UserDaoImpl(sqlSessionFactory);//User user = userDao.selectUser(2);查询///*修改User user = userDao.selectUser(2);user.setAge(90);userDao.updateUser(user);*//**添加User user = new User();user.setUsername("kkddkdk");user.setAge(20);userDao.addUser(user);*//** * 删除 userDao.deleteUser(2);*/} catch (IOException e) {e.printStackTrace();}finally{if(session != null){session.close();}}}}

在测试类Mybatistest.java中放开注释依次测试即可。

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