MyBatis官⽹地址：http://www.mybatis.org/mybatis-3/
MyBatis官网地址.png
简单回顾一下，搭建MyBatis开发环境可分为以下几个步骤：
1、添加MyBatis的Maven依赖
2、创建user数据表
3、编写User实体类
4、编写映射⽂件UserMapper.xml
5、编写核⼼⽂件sqlMapConfig.xml
6、编写测试类
接下来我们依次按照步骤来搭建一个基本环境，在IDEA中新建一个Maven项目，项目名称为mybatis-quick-start
1、在项目的pom.xml文件中引入相应的依赖
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.lagou</groupId>
<artifactId>mybatis-quick-start</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.encoding>UTF-8</maven.compiler.encoding>
<java.version>1.8</java.version>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<!--mybatis坐标-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<!--mysql驱动坐标-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.18</version>
</dependency>
<!--单元测试坐标-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!--⽇志坐标-->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.12</version>
</dependency>
</dependencies>
</project>
2、创建user数据表(用Navicat客户端工具连接到数据库，新建一个名称为mybatis的数据库，然后创建user表)，具体创建表的SQL如下：
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
`username` varchar(50) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '用户名称',
`password` varchar(50) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '密码',
`nickname` varchar(50) COLLATE utf8mb4_bin DEFAULT NULL COMMENT '昵称',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
3、编写User实体类（编写一个User实体类，对应的实体属性和user表中的字段相对应）
package study.lagou.com.pojo;
/**
* @Description: 功能描述
* @Author houjh
* @Email: happyxiaohou@gmail.com
* @Date: 2021-1-27 22:13
*/
public class User {
/**
* 主键信息
*/
private Integer id;
/**
* 用户名称
*/
private String username;
/**
* 用户密码
*/
private String password;
/**
* 用户昵称
*/
private String nickname;
public Integer getId() {
return id;
}
public void setId(Integer 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 String getNickname() {
return nickname;
}
public void setNickname(String nickname) {
this.nickname = nickname;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
", nickname='" + nickname + '\'' +
'}';
}
}
4、编写映射⽂件UserMapper.xml（注意一下，现在我们编写xml配置文件的时候添加了对应的约束头）
Mapper.xml文件约束头如下
<?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">
完整的UserMapper.xml文件如下
<?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="study.lagou.com.mapper">
<select id="findAll" resultType="study.lagou.com.pojo.User">
SELECT * FROM user
</select>
</mapper>
5、编写核⼼⽂件sqlMapConfig.xml(对应的核心配置文件我们也加入对应的约束头文件，注意数据库连接信息请配置成自己的数据库连接信息)
config.xml核心配置文件约束头
<?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">
完整的sqlMapConfig.xml配置文件如下
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&serverTimezone=Hongkong&characterEncoding=utf-8&autoReconnect=true"/>
<property name="username" value="root"/>
<property name="password" value="111111"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="study/lagou/com/mapper/UserMapper.xml"/>
</mappers>
</configuration>
6、编写测试类
package study.lagou.com.test;
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 org.junit.Test;
import study.lagou.com.pojo.User;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
/**
* @Description: 功能描述
* @Author houjh
* @Email: happyxiaohou@gmail.com
* @Date: 2021-3-22 19:48
*/
public class MyBatisTest {
@Test
public void testFindAll() throws IOException {
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
SqlSession sqlSession = sqlSessionFactory.openSession();
List<User> users = sqlSession.selectList("study.lagou.com.mapper.findAll");
for (User user : users) {
System.out.println(user);
}
//方法调用完成注意关闭sqlSession
sqlSession.close();
}
}
7、运行测试，查看结果
运行测试结果.gif
上一篇笔记地址:https://www.jianshu.com/p/2d72f4604124
