MyBatis简单配置

1、在Maven的pom.xml中导入Mybatis和MySQL数据库驱动依赖

    
    
        org.mybatis
        mybatis
        3.5.5
        

    
    
        mysql
        mysql-connector-java
        5.1.38
    

2、在Maven项目中的resources下创建mybatis-config.xml配置文件

3、在com.tyh.utils下创建MybatisUtils.java工具类

package com.tyh.utils;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

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

public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            String mybatisConfig = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(mybatisConfig);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}

4、在com.tyh.pojo中创建Admin.java实体类

5、在Maven:main.java.com.tyh.mapper中创建AdminMapper.java接口，即dao接口

package com.tyh.mapper;

import com.tyh.pojo.Admin;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface AdminMapper {
    //查询所有用户
    List selectAll();
}

6、在Maven:main/resources/com/tyh/mapper中创建AdminMapper.xml配置文件，即daoImpl实现类

    
        select * from admin;
    

7、测试：在Maven中test.java.com.tyh.test下创建TestAdminMybatis.java测试类

先导入Test依赖：

    junit
    junit
    4.13.2
    test

再编写测试代码： 

package com.tyh.test;

import com.tyh.mapper.AdminMapper;
import com.tyh.pojo.Admin;
import com.tyh.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;

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

public class TestAdminMyBatis {
    @Test
    public void TestSelectAll() throws IOException {
        //1、获取SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = MybatisUtils.getSqlSessionFactory();

        //2、获取SqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();

        //3、获取Mapper接口的代理对象
        AdminMapper adminMapper = sqlSession.getMapper(AdminMapper.class);

        //4、执行方法
        List list = adminMapper.selectAll();
        for (Admin a : list){
            System.out.println(a);
        }

        //5、释放资源
        sqlSession.close();
    }
}