mybatis 配置

编写实体类
编写核心配置文件
编写接口
编写mapper.xml
测试

resources 下的db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mybatis?&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8&useSSL=true
username=root
password=123456


mybatis-config.xml


<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

<!--  引入外部配置文件-->

    <properties resource="db.properties"/>

<!--  k可以给实体类起别名  -->
<!--    通过类-->
<typeAliases>
    <typeAlias type="com.yao.pojo.User" alias="User"/>

<!--    通过包-->
<!--    <package name="com.yao.pojo"/>-->
</typeAliases>


    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/yao/dao/UserMapper.xml"/>
<!--        <package name="com.yao.dao"/>-->
    </mappers>
</configuration>


工具包
utils下的
MybatisUtils

public class MybatisUtils {

    static SqlSessionFactory sqlSessionFactory = null;

    static {
        try {
            //使用Mybatis第一步 ：获取sqlSessionFactory对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }

}