MyBatis笔记——初次环境配置

2023-08-22 15:20:34

简单介绍

MyBatis 本是apache的一个开源项目iBatis, 2010年这个项目由apache software foundation 迁移到了google code，并且改名为MyBatis 。2013年11月迁移到Github。
iBATIS一词来源于“internet”和“abatis”的组合，是一个基于Java的持久层框架。iBATIS提供的持久层框架包括SQL Maps和Data Access Objects（DAO）

1.导包

核心包

依赖包

当然还要有数据库驱动包

2.写xml配置

项目结构如下

2.1添加SqlMapConfig.xml配置文件

<?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>

    <environments default="development">

        <environment id="development">

            <transactionManager type="JDBC" />

            <dataSource type="POOLED">

                <property name="driver" value="com.mysql.jdbc.Driver" />

                <property name="url" value="jdbc:mysql://localhost:3306/db_pwc" />

                <property name="username" value="pwc" />

                <property name="password" value="123456" />

            </dataSource>

        </environment>

    </environments>

    <mappers>

        <mapper resource="com/pwc/pojo/User.xml" />

    </mappers>

</configuration>

2.2添加POJO类User.java

package com.pwc.pojo;

public class User {

    private int id;

    private String name;

    private int age;

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

    @Override

    public String toString() {

        return "User [id=" + id + ", name=" + name + ", age=" + age + "]";

    }

    public User(int id, String name, int age) {

        super();

        this.id = id;

        this.name = name;

        this.age = age;

    }

    public User() {

    }

}

2.3添加POJO类User的映射文件User.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="com.pwc.dao.mapper.UserMapper">

    <select id="findById" parameterType="int" resultType="com.pwc.pojo.User">

        SELECT * FROM User WHERE id = #{id}

    </select>

    <insert id="insert" parameterType="com.pwc.pojo.User">

        INSERT INTO User(name,age) VALUES(#{name},#{age})

    </insert>

    <delete id="deleteById" parameterType="int">

        DELETE * FROM User WHERE id=#{id}

    </delete>

    <select id="findByAge" parameterType="int" resultType="com.pwc.pojo.User">

        SELECT * FROM User WHERE age=#{age}

    </select>

</mapper>

3.测试

package com.pwc.test;

import org.apache.ibatis.session.SqlSession;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import com.pwc.pojo.User;

public class Test {

    public static void main(String[] args) {

        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();

        SqlSessionFactory factory = builder.build(Test.class.getClassLoader().getResourceAsStream("SqlMapConfig.xml"));

        SqlSession session = factory.openSession();

        User user=session.selectOne("findById", 1);

        System.out.println(user.toString());

    }

}

测试结果如下：
User [id=1, name=pwc, age=18]

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