SpringBoot集成MybatisPlus
前言
我们在开发中经常需要操作数据库,传统的mybatis需要编写mapper和xml文件,工作量比较大,可以集成mybatisplus减少代码量,提高开发效率
MybatisPlus介绍
简介 | MyBatis-Plus
MyBatis-Plus 是一个 MyBatis 的增强工具,在 MyBatis 的基础上只做增强不做改变,为简化开发、提高效率而生。
添加表及数据
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`
(
id BIGINT NOT NULL COMMENT '主键ID',
name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
age INT NULL DEFAULT NULL COMMENT '年龄',
email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
PRIMARY KEY (id)
);
DELETE FROM `user`;
INSERT INTO `user` (id, name, age, email) VALUES
(1, 'Jone', 18, 'test1@baomidou.com'),
(2, 'Jack', 20, 'test2@baomidou.com'),
(3, 'Tom', 28, 'test3@baomidou.com'),
(4, 'Sandy', 21, 'test4@baomidou.com'),
(5, 'Billie', 24, 'test5@baomidou.com');
创建工程添加依赖
创建一个空的 Spring Boot 工程,引入 MyBatis-Plus Starter 依赖
添加了mybatisPlus的依赖就不需要添加mybatis的了,以免冲突
Spring Boot2
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.11</version>
</dependency>
Spring Boot3
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-spring-boot3-starter</artifactId>
<version>3.5.11</version>
</dependency>
<!-- 数据库驱动(以 MySQL 为例) -->
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<scope>runtime</scope>
</dependency>
配置
spring:
application:
name: joinDemo
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/sbdemo
username: root
password: 123456
hikari:
maximum-pool-size: 10
connection-timeout: 30000
mybatis-plus:
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
在 Spring Boot 启动类中添加 @MapperScan
注解,扫描 Mapper 文件夹:
@SpringBootApplication
@MapperScan("com.sky.joindemo.mapper")
public class JoinDemoApplication {
public static void main(String[] args) {
SpringApplication.run(JoinDemoApplication.class, args);
}
}
类
@Getter
@Setter
@ToString
@Accessors(chain = true)
public class User implements Serializable {
private static final long serialVersionUID = 1L;
/**
* 主键ID
*/
@TableId(type = IdType.AUTO)
private Long id;
/**
* 姓名
*/
private String name;
/**
* 年龄
*/
private Integer age;
/**
* 邮箱
*/
private String email;
}
/**
* <p>
* Mapper 接口
* </p>
*
* @author sky
* @since 2025-03-25
*/
public interface UserMapper extends BaseMapper<User> {
}
单元测试
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.sky.joindemo.entity.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import java.util.List;
@SpringBootTest
class UserMapperTest {
@Autowired
private UserMapper userMapper;
@Test
public void testSelect() {
System.out.println(("----- selectAll method test ------"));
List<User> userList = userMapper.selectList(null);
Assert.isTrue(5 == userList.size(), "");
userList.forEach(System.out::println);
}
@Test
public void testSelectByWrapper() {
//实体类上添加这个注解,可以链式访问@Accessors(chain = true)
User user = new User()
.setName("Jack").setAge(18);
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper.like(!StringUtils.isEmpty(user.getName()), "name", user.getName())
.eq(user.getAge() != null, "age", user.getAge());
List<User> userList = userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
}
@Test
public void testSelectByLambdaQueryWrapper() {
User user = new User()
.setName("Jack").setAge(18);
LambdaQueryWrapper<User> lambdaQueryWrapper = new LambdaQueryWrapper<>();
lambdaQueryWrapper.like(!StringUtils.isEmpty(user.getName()),User::getName, "Jack")
.eq(user.getAge() != null,User::getAge, 18);
List<User> userList = userMapper.selectList(lambdaQueryWrapper);
userList.forEach(System.out::println);
}
}
代码生成器
使用代码生成器的话要引入
<!-- 模板引擎 -->
<dependency>
<groupId>org.apache.velocity</groupId>
<artifactId>velocity-engine-core</artifactId>
<version>2.3</version>
</dependency>
import com.baomidou.mybatisplus.generator.FastAutoGenerator;
import com.baomidou.mybatisplus.generator.engine.VelocityTemplateEngine;
import java.nio.file.Paths;
import java.util.Scanner;
public class CodeGenerator {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入要生成代码的表名,多个表名用逗号分隔:");
String tableNamesInput = scanner.nextLine();
String[] tableNames = tableNamesInput.split(",");
FastAutoGenerator.create("jdbc:mysql://localhost:3306/sbdemo", "root", "123456")
.globalConfig(builder -> builder
.author("sky")// 开启 swagger 模式
.outputDir(Paths.get(System.getProperty("user.dir")) + "/src/main/java")
.commentDate("yyyy-MM-dd")
)
.packageConfig(builder -> builder
.parent("com.sky.joindemo")
.entity("entity")
.mapper("mapper")
.service("service")
.serviceImpl("service.impl")
.xml("mapper.xml")
)
.strategyConfig(builder -> builder
.addInclude(tableNames)
.entityBuilder()
.enableLombok()
)
.templateEngine(new VelocityTemplateEngine())
.execute();
}
}
总结
mybatisPlus集成了很多现成的方法,可以快速的实现单表的增删改查。
生成的代码未必满足业务的需求,可以根据自己的需求微调一下,比如user类添加了@Accessors(chain = true)注解,可以实现链式赋值,主键也手工增加了@TableId(type = IdType.AUTO)注解