【Mybatis學習筆記】01 配置搭建Mybatis
阿新 • • 發佈：2019-02-08
一、什麼是Mybatis
3.加入配置檔案src下建立
4.userMapper.java
5.建立POJO
6.建立工具類
7.建立測試用例
- mybatis是對jdbc的封裝
- 自動將輸入引數對映到sql語句的動態引數上
- 自動將sql語句執行的結果對映成java物件。
3.加入配置檔案src下建立- dp.properties
| jdbc.driver=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/testjdbc.username=rootjdbc.password=123456 |
- log4j.properties
| log4j.rootLogger=DEBUG,Console |
- mybaties核心配置檔案：
| 1.mybaties-config.xml<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" |
- UserMapper.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" ><!-- namespace="對應的介面完整包名+類名"，通過namespace找介面。介面名字為XXXdao/mapper都可以。 --> <!-- statement --> <!-- <insert> <delete> <update> <select>--> <!-- paramterType為什麼不用寫全名？ 因為mybatis給引數的全名起了別名。具體參考 --><mapper namespace="com.demo.mapper.UserMapper"> <select id="selectUser" parameterType="int" resultType="user"> select * from user where id= #{id} </select></mapper> |
5.建立POJO
6.建立工具類| public class MybatisUtil { private static SqlSessionFactory sqlSessionFactory=null; static { try { InputStream in = Resources.getResourceAsStream("mybatis-config.xml"); sqlSessionFactory = new SqlSessionFactoryBuilder().build(in); } catch (IOException e) { e.printStackTrace(); } } private MybatisUtil() {} public static SqlSession getSqlSession() { return sqlSessionFactory.openSession(); }} |
| package com.demo.mapper;import org.apache.ibatis.session.SqlSession;import org.junit.Test;import com.demo.pojo.User;import com.demo.util.MybatisUtil;public class UserMapperTest { @Test public void testSelectUser() { SqlSession session = MybatisUtil.getSqlSession(); UserMapper userMapper = session.getMapper(UserMapper.class); User user = userMapper.selectUser(1); System.out.println(user); session.close(); }} |