测试MyBatis功能

测试添加功能

package com.sympa.mybatis.test;

import com.sympa.mybatis.mapper.UserMapper;
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 org.junit.jupiter.api.Test;

import java.io.IOException;
import java.io.InputStream;

public class MybatisTest {

    @Test
    public void testMybatis() throws IOException {
        //加载核心配置文件
        InputStream is = Resources.getResourceAsStream("mybatis.config.xml");
        //获取sqlSessionFactoryBuilder
        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        //通过核心配置文件所对应的字节输入流创建工厂类SqlSessionFactory，生产SqlSession对象
        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
        //创建SqlSession对象，此时通过SqlSession对象所操作的sql都必须手动提交或回滚事务
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //创建SqlSession对象，此时通过SqlSession对象所操作的sql都会自动提交
        //SqlSession sqlSession = sqlSessionFactory.openSession(true);
        //通过代理模式创建UserMapper接口的代理实现类对象
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        //调用UserMapper接口中的方法，就可以根据UserMapper的全类名匹配元素文件，通过调用的方法名匹配映射文件中的SQL标签，并执行标签中的SQL语句
        //测试添加功能
        int result = userMapper.insertUser();
        System.out.println("result:" + result);
        //提交事务
        sqlSession.commit();
    }
}

<insert id="insertUser">
    insert into t_user values(null, '张三', '123456', 18, '男', '123@qq.com')
</insert>

测试查询功能

查询功能标签必须设置resultType或resultMap

• resultType：设置默认映射关系
• resultMap：设置自定义的映射关系

package com.sympa.mybatis.test;

import com.sympa.mybatis.mapper.UserMapper;
import com.sympa.mybatis.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 org.junit.jupiter.api.Test;

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

public class MybatisTest {

    @Test
    public void testMybatis() throws IOException {
        InputStream is = Resources.getResourceAsStream("mybatis.config.xml");

        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        List<User> result = userMapper.getUserById();
        result.forEach(user -> System.out.println(user));
    }
}

设置结果映射

<!--User getUserById();-->
<select id="getUserById" resultType="com.sympa.mybatis.pojo.User">
    select * from t_user
</select>

封装SqlSessionUtils工具类，获取SqlSession对象

package com.sympa.mybatis.utils;

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;

public class SqlSessionUtils {

    public static SqlSession getSqlSession(){
        InputStream is = null;
        try {
            is = Resources.getResourceAsStream("mybatis.config.xml");
        } catch (IOException e) {
            e.printStackTrace();
        }
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        return sqlSession;
    }
}