SpringBoot集成MybatisPlus

原创于 2025-03-25 18:09:04 发布 · 513 阅读

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CC 4.0 BY-SA版权

文章标签：

#spring boot #java #spring

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();
    }
}