IDEA 创建第一个MyBatis

最近学习了一下MyBatis，在学习的过程中获得了一些启发，也遇到了一些困难，发此博客让初学者少走弯路，同时可以让自己的记忆更加深刻。

1.首先 File→New→Project
2.接下来直接点next→next→finish（名字随便起就行）
3根据目录来创建（MyBatis只需要导入三个包就行，如果你是5.0数据库则需要导入5.0数据库的包）
如果你是第一次创建xml文件 IDEA里并没有相应的模板 你只需要点击new→file，后缀名写.xml就行

4.City

package sc.domain;

public class City {
    
    
    private int cid;
    private String cname;
    private int pid;

    public City() {
    
    
    }

    public City(int cid, String cname, int pid) {
    
    

        this.cid = cid;
        this.cname = cname;
        this.pid = pid;
    }

    public int getCid() {
    
    

        return cid;
    }

    public void setCid(int cid) {
    
    
        this.cid = cid;
    }

    public String getCname() {
    
    
        return cname;
    }

    public void setCname(String cname) {
    
    
        this.cname = cname;
    }

    public int getPid() {
    
    
        return pid;
    }

    public void setPid(int pid) {
    
    
        this.pid = pid;
    }
}

5.CityMapper

package sc.mapper;

import sc.domain.City;

import java.util.List;

public interface CityMapper {
    
    
    public List<City> findAllUser();
}

6CityMapper.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="sc.mapper.CityMapper">
    <select id="findAllUser"  resultType="sc.domain.City">
        select * from city
    </select>
</mapper>

7Test

package sc.Test;

import org.apache.ibatis.session.SqlSession;
import sc.domain.City;
import sc.mapper.CityMapper;
import sc.utils.MybatisUtil;

import java.util.List;

public class Test {
    
    
    public static void main(String[] args) {
    
    
        SqlSession session =  MybatisUtil.getSession();
        List<City> list= session.getMapper(CityMapper.class).findAllUser();
        for (City city : list) {
    
    
            System.out.println(city.getCname());
        }
    }
}

8.MybatisUtil

package sc.utils;

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

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

public class MybatisUtil {
    
    

    //加载mybatis配置文件
    //创建sqlsessionfactory对象
    //创建sqlsession连接对象
    //创建关闭sqlsession连接对象
    private static SqlSessionFactory sessionFactory;


    static{
    
    

        String resource="mybatis.xml";
        try {
    
    
            InputStream is=Resources.getResourceAsStream(resource);
            sessionFactory=new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
    
    
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }

    public static SqlSession getSession(){
    
    
        return sessionFactory.openSession();
    }


    public static void closeSession(SqlSession session){
    
    
        if(session!=null){
    
    
            session.close();
        }
    }




}

9.mybatis.xml

<?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>
<environments default="sc">
    <environment id="sc">
        <transactionManager type="JDBC"></transactionManager>
        <dataSource type="POOLED">
            <!--配置源文件-->
            <property name="driver" value="com.mysql.cj.jdbc.Driver"></property>
            <!--接口大部分都是3306,（我这里是3308），如果你数据库是5.0或者以下的这不需要加characterEncoding = utf8&amp;&amp;useSSL=false&amp;serverTimezone=UTC-->
            <property name="url" value="jdbc:mysql://localhost:3308/db_shopping?characterEncoding = utf8&amp;&amp;useSSL=false&amp;serverTimezone=UTC"></property>
            <property name="username" value="root"></property>
            <property name="password" value="root"></property>
        </dataSource>
    </environment>
</environments>
    <mappers>
        <mapper resource="sc/mapper/CityMapper.xml"></mapper>
    </mappers>
</configuration>

10数据库表

11运行结果

希望会对初学者有用。