mybatis 注解入门案例

mybatis 注解入门

//用户持久层接口 public interface IUserDao { @Select("select * from User where id=41") List<User> findAll(); }

主配置文件

<?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> <!--配置环境--> <environments default="mysql"> <!--配置mysql环境--> <environment id="mysql"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <!--配置链接数据库标准信息--> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis01"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <!--使用注解时应该使用class来指定class属性的全限定类名--> <mapper class="com.ljq.dao.IUserDao"/> </mappers> </configuration>

测试类

public class MybatisTest { //入门案例 public static void main(String[] args) throws IOException { //1.读取配置文件 InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml"); //2.创建SqlSessionFactory工厂 SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder(); SqlSessionFactory factory = builder.build(in); //3.使用工厂生产SqlSession对象 SqlSession session = factory.openSession(); //4.使用SqlSessiion创建Dao接口的代理对象 IUserDao userDao = session.getMapper(IUserDao.class); //5.使用代理对象执行方法 List<User> users = userDao.findAll(); for (User user:users){ System.out.println(user); } //6.释放资源 session.close(); in.close(); } }