Mybatis

IDEA创建一个空项目，然后添加Maven模块

maven项目路径如下所示

--项目名
	--/src
		--/main #存放主程序java代码和资源
			--/java	#java代码
			--/resources #配置文件和资源等，放到这里的文件等同于放到了根目录下
		--/test #测试程序文件夹
			--/java
			--/resources
	--/pom.xml   #maven 的核心配置文件

第一步：在pom文件中配置MySQL和mybatis依赖，并且设置打包方式为jar

 <packaging>jar</packaging>

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.11</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.mysql/mysql-connector-j -->
    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <version>8.0.31</version>
    </dependency>
</dependencies>

第二步：编写mybatis核心配置文件mybatis-config.xml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="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://mysql数据库地址/数据库名称"/>
                <property name="username" value="用户名"/>
                <property name="password" value="密码"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        //此处填写引入mapper文件
        <mapper resource="studentMapper.xml"/>
        <mapper resource="teacherMapper.xml"/>
    </mappers>
</configuration>

第三步：编写mapper文件，并在mybatis-config.xml文件中引入mapper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="org.mybatis.example.BlogMapper">
    //此处填写sql语句
    <insert id="studentInsert">
        insert into stu values (null,'winter','nan');
    </insert>
</mapper>

第四步：编写mybatis程序。在java目录下新建一个类

public class mybatisTest {
        public static void main(String[] args) throws Exception{
            
            //获取SqlSessionFactoryBuilder对象
            SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
            //获取SqlSessionFactory对象
            InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
            //Resources.getResourceAsStream方法是从类路径加载文件，移植性强
            //核心配置文件的文件名不固定，只要能通过Resources.getResourceAsStream方法获取到就行
            SqlSessionFactory factory = builder.build(is);
            //获取SqlSession
            SqlSession sqlSession = factory.openSession();
            //执行sql语句
            int count =  sqlSession.insert("studentInsert");//此处的字符串要和mapper文件中的insert标签的id对应
            System.out.println("改动了"+count+"条记录");
            //commit手动提交
            sqlSession.commit();
        }
    }