mybatis

<?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="development">
<environment id="development">
<!-- 采用jdbc事务管理其 -->
<transactionManager type="JDBC"/>
<!-- 配置数据源 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="lzj_aeon+"/>
</dataSource>
</environment>
</environments>
<mappers>
<!-- 引入实体类的映射文件 -->
<mapper resource="edu/aeon/mybatis/entity/User.mapper.xml"/>
</mappers>
</configuration>

<?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="edu.aeon.mybatis.entity">
<select id="selectAllUsers" resultType="edu.aeon.mybatis.entity.User">
select * from user
</select>
</mapper>

package edu.aeon.mybatis.entity;
/**
 * user实体类
 * @author QQ1584875179
 */
public class User {
    //用户id
    private int uid;
    //用户名
    private String uname;
    //用户密码
    private String upw;
    //↓setter/getter
    public int getUid() {
        return uid;
    }
    public void setUid(int uid) {
        this.uid = uid;
    }
    public String getUname() {
        return uname;
    }
    public void setUname(String uname) {
        this.uname = uname;
    }
    public String getUpw() {
        return upw;
    }
    public void setUpw(String upw) {
        this.upw = upw;
    }
    @Override
    public String toString() {
        return uid+"\t"+uname+"\t"+upw;
    }
}

package edu.aeon.mybatis.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;
/**
 * mybatis工具类
 * @author QQ1584875179
 */
public class MyBatisUtils {
    /**
     * @param resource 构建资源来自resource
     * @return 通过构建资源构建的SqlSessionFactory实例
     * @throws IOException 此处采取抛出异常到顶层、然后我们统一去处理
     */
    public static SqlSessionFactory getSqlSessionFactory(String resource) throws IOException{
        InputStream inputStream = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }
    /**
     * @param resource 构建资源来自resource
     * @return 通过构建资源构建的SqlSessionFactory实例的openSession()方法获得SqlSession实例
     * @throws IOException 此处采取抛出异常到顶层、然后我们统一去处理
     */
    public static SqlSession getSqlSession(String resource) throws IOException{
        return getSqlSessionFactory(resource).openSession();
    }
}

package edu.aeon.mybatis.test;

import java.io.IOException;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import edu.aeon.mybatis.entity.User;
import edu.aeon.mybatis.utils.MyBatisUtils;

public class Demo01Test {
    public static void main(String[] args) {
        try {
            SqlSession sqlSession = MyBatisUtils.getSqlSession("mybatis/mybatis.xml");
            List<User> userList=sqlSession.selectList("edu.aeon.mybatis.entity.selectAllUsers");
            System.out.println("用户id\t用户名\t用户密码");
            for(User user:userList){
                System.out.println(user);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
}

##创建一个mybatis的数据库
create database mybatis;
##切换我们刚才创建的mybatis数据库为当前数据库
use mybatis;
##创建(user)表
create table user(uid int(3) primary key auto_increment,uname varchar(16),upw varchar(16));
##想user表中插入5条测试数据
insert into user(uname,upw) values(‘lzj1‘,‘aeon1‘);
insert into user(uname,upw) values(‘lzj2‘,‘aeon2‘);
insert into user(uname,upw) values(‘lzj3‘,‘aeon3‘);
insert into user(uname,upw) values(‘lzj4‘,‘aeon4‘);
insert into user(uname,upw) values(‘lzj5‘,‘aeon5‘);