一个 Mybatis Demo，用于初学者练习，欢迎评论区进行讨论学习。
前期准备
依赖引入
<!--引入MyBatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.9</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.29</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.3.0</version>
</dependency>
配置数据库
这里使用的是 JDBC.properties
driver = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3307/mybatis
name = root
password = 1234
准备数据
-
创建数据库
CREATE DATABASE mybatis; -
创建表
CREATE TABLE tb_user ( id char(32) NOT NULL, user_name varchar(32) DEFAULT NULL, password varchar(32) DEFAULT NULL, name varchar(32) DEFAULT NULL, age int(10) DEFAULT NULL, sex int(2) DEFAULT NULL, birthday date DEFAULT NULL, created datetime DEFAULT NULL, updated datetime DEFAULT NULL, PRIMARY KEY (id) ) ENGINE = InnoDB CHARSET = utf8; -
生成数据
这里我是直接使用 Navicat 的数据生成功能
配置Mybatis配置文件
这里 PageHelper 分页插件可以选择是否添加是否添加
<?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>
<!--引入jdbc.properties-->
<properties resource="classpath:jdbc.properties"/>
<!-- 配置分页插件-->
<plugins>
<plugin interceptor="org.apache.ibatis.plugin.Interceptor">
<property name="dialect" value="mysql"/>
<property name="offsetAsPageNum" value="false"/>
<property name="rowBoundsWithCount" value="false"/>
<property name="pageSizeZero" value="true"/>
<property name="reasonable" value="false"/>
<property name="supportMethodsArguments" value="false"/>
<property name="returnPageInfo" value="none"/>
</plugin>
</plugins>
<!-- 环境，可以配置多个，default：指定采用哪个环境 -->
<environments default="dev">
<environment id="dev">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${name}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<!--配置映射器-->
<mappers>
<mapper resource="com/echo/mybatis/UserMapper.xml"/>
</mappers>
</configuration>
编写User类
package com.echo.mybatis;
import java.text.SimpleDateFormat;
import java.util.Date;
public class User {
private String id;
private String userName;
private String password;
private String name;
private Integer age;
private Integer sex;
private Date birthday;
private String created;
private String updated;
public String getId() {
return id;
}
public void setId(String 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 getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public Integer getSex() {
return sex;
}
public void setSex(Integer sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getCreated() {
return created;
}
public void setCreated(String created) {
this.created = created;
}
public String getUpdated() {
return updated;
}
public void setUpdated(String updated) {
this.updated = updated;
}
@Override
public String toString() {
return "User{" +
"id='" + id + ''' +
", userName='" + userName + ''' +
", password='" + password + ''' +
", name='" + name + ''' +
", age=" + age +
", sex=" + sex +
", birthday='" + new SimpleDateFormat("yyyy-MM-dd").format(birthday) + ''' +
", created='" + created + ''' +
", updated='" + updated + ''' +
'}';
}
}
编写映射类
名称：UserMapper.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.echo.mybatis.User">
<select id="findAll" resultType="com.echo.mybatis.User">
SELECT * FROM tb_user
</select>
</mapper>
编写测试类
package com.echo.mybatis;
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;
public class MybatisTest {
public static void main(String[] args) throws IOException {
//指定全局配置文件
String resource = "mybatis-config.xml";
//读取配置文件
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession sqlSession = sessionFactory.openSession();
List<User> list = sqlSession.selectList("findAll");
System.out.println(list);
sqlSession.close();
}
}
