Mybatis-环境搭建

一、导入坐标

<!--mybatis 坐标 -->
<dependency>
　　<groupId>org.mybatis</groupId>
　　<artifactId>mybatis</artifactId>
　　<version>3.4.5</version>
</dependency>
<!--mysql 驱动坐标 -->
<dependency>
　　<groupId>mysql</groupId>
　　<artifactId>mysql-connector-java</artifactId>
　　<version>5.1.6</version>
　　<scope>runtime</scope>
</dependency>

二、编写UserMapper映射文件

<?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="userMapper">
    <select id="findAll" resultType="com.finnlee.pojo.User">
        select * from user
    </select>
</mapper>

三、编写MyBatis核心文件

<?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>
    <environments default="develop">
        <environment id="develop">
            <transactionManager type="jdbc"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/demo?characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
 
    <mappers>
        <mapper resource="com/finnlee/mapper/UserMapper.xml"/>
    </mappers>
</configuration>

四、测试代码

// 加载核心配置文件
   InputStream resourceAsStream = Resources.getResourceAsStream("mybatis.xml");
   // 获得 sqlSession 工厂对象
   SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
   // 获得 sqlSession 对象
   SqlSession sqlSession = sqlSessionFactory.openSession();
 
   List<User> userList = sqlSession.selectList("userMapper.findAll");
   System.out.println(userList);
   //关闭资源
   sqlSession.close();