mybatis 原生写法创建项目

一、创建全局文件

<?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>

    <!--默认的数据库配置 修改成mysql   之前是 development-->
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/qy100?CharacterEncoding=utf-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>

    <!--mybatis 是使用
    1.简单的xml 或者
    2.注解来配置和映射原生类型，接口和java的pojo(普通老式java对象)-->
    <!--为数据库中记录的-->
    <!--这里就是将在dao层下创建的DeptMapper.xml映射文件  加入到全局文件中  -->
    <mappers>
        <mapper resource="com/aaa/dao/DeptMapper.xml"/>
    </mappers>

</configuration>

二、创建实体类

package com.aaa.entity;

public class Dept {
    private int id;
    private String ename;
    private String job;
    private double sal;

    public Dept(int id, String ename, String job, double sal) {
        this.id = id;
        this.ename = ename;
        this.job = job;
        this.sal = sal;
    }

    public Dept(int id, String ename) {
        this.id = id;
        this.ename = ename;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public double getSal() {
        return sal;
    }

    public void setSal(double sal) {
        this.sal = sal;
    }

    @Override
    public String toString() {
        return "Dept{" +
                "id=" + id +
                ", ename='" + ename + '\'' +
                ", job='" + job + '\'' +
                ", sal=" + sal +
                '}';
    }
}

三、在DAO层中创建  mybatis-mapper.xml 映射文件。

<?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">

    <!--mybatis的原生接口。-->

    <!--工作空间就是
     1.我在dao层下 创建的DeptMapper 文件
     2.或者是对应的 dao 层中的接口。
     -->
<mapper namespace="com.aaa.dao.DeptMapper">
    <select id="selectDept" resultType="com.aaa.entity.Dept">
        select * from dept;
    </select>

    <delete id="deleteDept" parameterType="com.aaa.entity.Dept">
        delete from dept where id=5;
    </delete>

    <insert id="insertDept" parameterType="com.aaa.entity.Dept">
        insert  into dept (ename,job,sal) values("武王嬴荡","秦王",1200);
    </insert>

    <update id="updateDept" parameterType="com.aaa.entity.Dept">
        update dept set ename="嬴政" ,job="千古第一帝" where id=5;
    </update>

</mapper>

四、测试

package com.aaa.test;

import com.aaa.entity.Dept;
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;

/*  测试  mybatis原生的接口
*  1.Resources:资源类
*  2.SqlSessionFactoryBuilder:构建器
*  3.SqlSessionFactory :会话工厂
*
* */
public class Test {
    public static void main(String[] args) throws IOException {
        //1.加载全局文件和配置文件

        String resource="mybatis-config.xml";

        InputStream is = Resources.getResourceAsStream(resource);
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(is);

        //2.开启会话
        SqlSession sqlSession = ssf.openSession();
        List<Dept> deptList = sqlSession.selectList("com.aaa.dao.DeptMapper.selectDept");

        for (Dept dept:deptList
             ) {
            System.out.println("部门信息"+dept);
        }
        //2.关闭会话
        sqlSession.close();
    }
}

五、封装一个单列的会话工厂。

package com.aaa.util;

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;
// 懒汉模式   节省资源
public class Factory {
    private static SqlSessionFactory ssf=null;

    static{
        String resource="mybatis-config.xml";
        InputStream is=null;

        try {
             is = Resources.getResourceAsStream(resource);
             ssf = new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static SqlSessionFactory getSsf(){
        return ssf;
    }
    public static SqlSession getSqlSession(){
        return ssf.openSession();
    }
}

六、测试

package com.aaa.test;

import com.aaa.entity.Dept;
import com.aaa.util.Factory;
import org.apache.ibatis.session.SqlSession;

import java.util.List;
/*
*  1.增删改查 注意！执行增删改的操作时  查询语句只能放在后面执行   否则报错！
*  2.进行增删改操作  需要进行提交！
*
* */
public class Test02 {
    public static void main(String[] args) {
        //利用单列的工厂类 获得连接
        SqlSession sqlSession = Factory.getSqlSession();

        //1.增加
        sqlSession.insert("com.aaa.dao.DeptMapper.insertDept");
        sqlSession.commit();
        //2.修改
        sqlSession.update("com.aaa.dao.DeptMapper.updateDept");
        sqlSession.commit();
        //3.删除
        sqlSession.delete("com.aaa.dao.DeptMapper.deleteDept");
        sqlSession.commit();

        //4.查询
        List<Dept> deptList = sqlSession.selectList("com.aaa.dao.DeptMapper.selectDept");

        for (Dept dept:deptList
             ) {
            System.out.println("部门信息"+dept);
        }
        //关闭会话
       sqlSession.close();
    }
}