通过MyBaits获取用户信息
1、编写pojo(user.class)
2、在lib下放置三个jar包
3、编写配置文件
4、创建Userdao.class
public User getUserById(int userId)
{
User user=null;
SqlSession session=null;
SqlSessionFactory factory=null;
try {
InputStream is=Resources.getResourceAsStream("mybatis-config.xml");//读取配置文件
factory=new SqlSessionFactoryBuilder().build(is);//创建session工厂
SqlSession session=factory.openSession();
user=session.selectOne("com.cyz.dao.UserDao.getUserById", userId);//第一个参数为下图user.xml中的namespace.id
} catch (Exception e) {
e.printStackTrace();
}
finally
{
MyBatisUtil.closeSqlSession(session);
}
return user;
}
5、创建映射文件(user.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">
<mapper namespace="com.cyz.dao.UserDao">
<select id="getUserById" resultType="com.cyz.po.User">
select * from user where userId=#{userid}
</select>
</mapper>
6、将映射文件在mybatis-config.xml中进行配置
7、创建测试类进行方法的测试