Mybatis快速入门

目录

框架介绍

ORM介绍

原始JDBC的操作问题分析

原始JDBC的操作问题解决方案

Mybatis介绍

Mybatis入门程序实现步骤

数据准备

映射配置文件

核心配置文件

实例测试

框架介绍

ORM介绍

原始JDBC的操作问题分析

原始JDBC的操作问题解决方案

Mybatis介绍

Mybatis入门程序实现步骤

数据准备

package demo1.bean;
 
public class Student {
    private Integer id;
    private String name;
    private Integer age;
 
    public Student() {
    }
 
    public Student(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
 
    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
 
    public Integer getId() {
        return id;
    }
 
    public void setId(Integer id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public Integer getAge() {
        return age;
    }
 
    public void setAge(Integer age) {
        this.age = age;
    }
}

映射配置文件

mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="StudentMapper">
<select id="selectAll" resultType="demo1.bean.Student">
    SELECT * FROM student
select>
mapper>

核心配置文件

configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    
    <environments default="tj1">
        <environment id="tj1">
            
            <transactionManager type="JDBC"/>
            
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/dp1"/>
                <property name="username" value="root"/>
                <property name="password" value="109923"/>
            dataSource>
        environment>
    environments>
    
    <mappers>
        <mapper resource="StudentMapper.xml"/>
    mappers>
configuration>

实例测试

package demo1.dao;
 
import demo1.bean.Student;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.*;
import org.junit.Test;
 
import java.io.InputStream;
import java.util.List;
 
public class StudentTest1 {
    @Test
    public void selectAll() throws Exception{
        //1.加载核心配置文件
        InputStream is = Resources.getResourceAsStream("MybatisConfig.xml");
        //2.获取SqlSession工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        //3.通过SqlSession工厂对象获取SqlSession对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //4.执行映射配置文件中的sql语句，并接收结果
        List list = sqlSession.selectList("StudentMapper.selectAll");
        //5.处理结果
        for(Student stu : list){
            System.out.println(stu);
        }
        //6.释放资源
        sqlSession.close();
        is.close();
    }
}