mybatis中的UserMapper.xml模板与测试mybatis的代码

2023-09-02

UserMapper.xml模板

方式一：

<?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="test">
    <select id="selectAll" resultType="com.hh.pojo.User">
        select * from tb_user
    </select>
</mapper>

方式二：（常用）

<?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.hh.mapper.UserMapper">
    <select id="selectAll" resultType="com.hh.pojo.User">
        select * from tb_user
    </select>
</mapper>

 

测试mybatis的代码

方式一：

package com.hh;

import com.hh.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * @author hh
 * @version 1.0
 * @DATE 2023-09-02 10:51:12
 */
public class MybatisDemo {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        SqlSession sqlSession = sqlSessionFactory.openSession();

        List<User> list = sqlSession.selectList("test.selectAll");
        System.out.println("list = " + list);

        sqlSession.close();

    }
}

 方式二：使用代理（常用）

package com.hh;

import com.hh.mapper.UserMapper;
import com.hh.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * @author hh
 * @version 1.0
 * @DATE 2023-09-02 10:51:12
 */
public class MybatisDemo2 {
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        SqlSession sqlSession = sqlSessionFactory.openSession();

        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> list = mapper.selectAll();
        System.out.println("list = " + list);
        sqlSession.close();

    }
}