MyBatis 框架之快速入门程序

时间：2024-10-24 19:36:50

一、使用 IDEA 快速创建 Maven 项目

关于如何快速创建 Maven 项目，这个可以参考下面这篇文章：

Maven 项目管理工具基础入门系列（一）

二、快速配置 MyBatis 依赖 jar 包

打开 pom.xml 文件，快速配置 jar 包，配置代码如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.mybatis</groupId>

  <artifactId>MyBatisDemo</artifactId>

  <packaging>war</packaging>

  <version>0.0.1-SNAPSHOT</version>

  <name>MyBatisDemo Maven Webapp</name>

  <url>http://maven.apache.org</url>

  <dependencies>

    <!-- MyBatis 依赖包 -->

    <dependency>

      <groupId>org.mybatis</groupId>

      <artifactId>mybatis</artifactId>

      <version>3.4.5</version>

    </dependency>

    <!-- 数据库驱动依赖包 -->

    <dependency>

      <groupId>mysql</groupId>

      <artifactId>mysql-connector-java</artifactId>

      <version>5.1.25</version>

    </dependency>

    <!-- junit 测试依赖包 -->

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>3.8.1</version>

      <scope>test</scope>

    </dependency>

  </dependencies>

  <build>

    <finalName>MyBatisDemo</finalName>

    <resources>

      <resource>

        <directory>src/main/java</directory>

        <includes>

          <include>**/*.xml</include>

        </includes>

        <filtering>true</filtering>

      </resource>

    </resources>

  </build>

</project>

三、快速创建实体类

创建 pojo 类 User.java，代码如下：

package com.mybatis.pojo;

public class User{

	private int id;

	private String username;

	private String password;

	private int age;

	public int getId() {

		return id;

	}

	public void setId(int id) {

		this.id = id;

	}

	public String getUsername() {

		return username;

	}

	public void setUsername(String username) {

		this.username = username;

	}

	public String getPassword() {

		return password;

	}

	public void setPassword(String password) {

		this.password = password;

	}

	public int getAge() {

		return age;

	}

	public void setAge(int age) {

		this.age = age;

	}

	@Override

	public String toString() {

		return "User [id=" + id + ", username=" + username + ", password="

				+ password + ", age=" + age + "]";

	}

}

四、快速创建实体类对应的数据表

新建数据库 mybatis_db，创建表 t_user，建表代码如下：

CREATE TABLE `t_user`  (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `username` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,

  `password` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT '',

  `age` int(11) NULL DEFAULT NULL,

  PRIMARY KEY (`id`) USING BTREE

) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;

五、快速创建 Mapper 接口

创建接口 UserDao.java，代码如下：

package com.mybatis.dao;

import com.mybatis.pojo.User;

public interface UserDAO {

	//新增用户

	public int addUser(User user);

	//根据id删除用户

	public int deleteUser(int id);

	//修改用户

	public int updateUser(User user);

	//根据id查询用户

	public User selectUserById(int id);

}

六、快速创建 Mapper 接口代理文件

创建 xml 文件 UserDaoMapper.xml，代码如下：

<?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.mybatis.dao.UserDao">

	<insert id="addUser" parameterType="com.mybatis.pojo.User">

       insert into t_user (username,password,age) values (#{username},#{password},#{age})

    </insert>

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

       delete from t_user where id=#{id}

    </delete> 

    <update id="updateUser" >

       update t_user set username=#{username},password=#{password},age=#{age} where id=#{id}

    </update>

    <select id="selectUserById" parameterType="int" resultType="com.mybatis.pojo.User">

       select * from t_user where id=#{id}

    </select>

</mapper>

七、快速添加 MyBatis 配置文件

创建 xml 文件 mybatis-comfig.xml，具体配置如下：

<?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>

	<!-- 配置 MyBatis 运行环境 -->

	<environments default="development">

		<environment id="development">

			<!-- 配置 JDBC 事务管理 -->

			<transactionManager type="JDBC" />

			<!-- POOLED 配置 JDBC 数据源连接池 -->

			<dataSource type="POOLED">

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

				<property name="url" value="jdbc:mysql://localhost:3306/mybatis_db?useUnicode=true&amp;characterEncoding=UTF-8" />

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

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

			</dataSource>

		</environment>

	</environments>

	<!-- 注册 UserDAO.xml -->

	<mappers>

		<mapper resource="com/mybatis/dao/UserDaoMapper.xml"/>

	</mappers>

</configuration>

八、快速创建测试类

创建测试类 Test.java，代码如下：

package com.mybatis.test;

import java.io.InputStream;

import org.apache.ibatis.session.SqlSession;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import com.mybatis.dao.UserDao;

import com.mybatis.pojo.User;

public class Test {

	public static void main(String[] args) {

		//加载MyBatis配置文件

		InputStream is = Test.class.getClassLoader().getResourceAsStream("mybatis-config.xml");

		SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();

		SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);

		//获取SqlSession

		SqlSession sqlSession = sqlSessionFactory.openSession();

		//获取实现接口的代理对象

		UserDao userDAO = sqlSession.getMapper(UserDao.class);

		//新增用户

		User user = new User();

		user.setUsername("孔乙己");

		user.setPassword("123456");

		user.setAge(21);

		System.out.println(userDAO.addUser(user));

		sqlSession.commit();

//		//删除用户

//		System.out.println(userDAO.deleteUser(1));

//		sqlSession.commit();

//

//		//查询用户

//		User user1 = userDAO.selectUserById(1);

//		System.out.println(user1);

//

//		//修改用户

//		User user2 = userDAO.selectUserById(1);

//		user2.setUsername("指南者");

//		System.out.println(userDAO.updateUser(user2));

//		sqlSession.commit();

	}

}

九、测试运行，结果如下图：

MyBatis 框架之快速入门程序

MyBatis 框架之快速入门程序

本程序和数据库相关的代码已经上传到 GitHub 上，GitHub 地址：点击这里直接获取项目源码

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-----------------------------------------MyBatis 框架之快速入门程序

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