SpringBoot 3.2.0 集成MyBatisPlus

依赖版本

• JDK 17
• Spring Boot 3.2.0
• MyBatis Plus 3.5.4.1

集成MyBatis-Plus

工程源码: Gitee

导入依赖

<properties>
    <java.version>17</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <spring-boot.version>3.2.0</spring-boot.version>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
    <mybatis-spring.version>3.0.3</mybatis-spring.version>
    <mybatis-plus.version>3.5.4.1</mybatis-plus.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>${mybatis-plus.version}</version>
        <exclusions>
            <exclusion>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>${mybatis-spring.version}</version>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
</dependencies>

编写application.yml配置文件

# ======== 数据源配置 ========
spring:
  datasource:
    driver-class-name: org.h2.Driver
    username: root
    password: test
  sql:
    init:
      schema-locations: classpath:db/schema-h2.sql
      data-locations: classpath:db/data-h2.sql

# ======== MybatisPlus配置 ========
mybatis-plus:
  # 搜索指定包别名
  type-aliases-package: com.yiyan.study.domain
  # 配置mapper的扫描，找到所有的mapper.xml映射文件
  mapper-locations: classpath:mapper/**/*xml
  # 配置驼峰
  configuration:
    # 是否开启自动驼峰命名规则（camel case）映射。默认值：true
    map-underscore-to-camel-case: true
    # 开启 Mybatis 二级缓存，默认为 true。
    cache-enabled: true
    # 日志输出实现。StdOutImpl 标准日志控制台输出
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  global-config:
    db-config:
      # 全局默认主键类型
      id-type: assign_id
      # 表名是否使用驼峰转下划线命名,只对表名生效。 默认true
      table-underline: true

编写基于MyBatisPlus的数据库操作

-- data-h2.sql
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');
       

-- schema-h2.sql
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)
);

实体类

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import java.io.Serial;
import java.io.Serializable;

@TableName(value = "`user`")
@Data
public class User implements Serializable {

    @TableId
    private Long id;
    private String name;
    private Integer age;
    private String email;

    @Serial
    @TableField(exist = false)
    private static final long serialVersionUID = 1L;
}

DAO（mapper）

import com.yiyan.study.domain.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface IUserDao extends BaseMapper<User> {

}

Service

import com.yiyan.study.domain.User;
import com.baomidou.mybatisplus.extension.service.IService;

public interface IUserService extends IService<User> {

}

ServiceImpl

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.yiyan.study.domain.User;
import com.yiyan.study.service.IUserService;
import com.yiyan.study.dao.IUserDao;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl extends ServiceImpl<IUserDao, User>
    implements IUserService{

}

mapper.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.yiyan.study.dao.IUserDao">

</mapper>

编写测试用例

package com.yiyan.study;

import com.yiyan.study.dao.IUserDao;
import com.yiyan.study.domain.User;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@Slf4j
@SpringBootTest
@DisplayName("MyBatis Plus Test")
public class MyBatisPlusTest {

    @Autowired
    private IUserDao userDao;

    @Test
    @DisplayName("MyBatis Plus Select Test")
    public void testSelect() {
        log.info(("----- selectAll method test ------"));
        List<User> userList = userDao.selectList(null);
        for (User user : userList) {
            log.info(user.toString());
        }
    }

    @Test
    @DisplayName("MyBatis Plus Insert Test")
    public void testInsert() {
        log.info(("----- insert method test ------"));
        User user = new User();
        user.setName("Alex");
        user.setAge(18);
        user.setEmail("alex@gmail.com");
        int result = userDao.insert(user);
        log.info("insert result: {}", result);
        User selectedById = userDao.selectById(user.getId());
        log.info("insert user info: {}", selectedById);
    }

    @Test
    @DisplayName("MyBatis Plus Update Test")
    public void testUpdate() {
        log.info(("----- update method test ------"));
        User user = userDao.selectList(null).get(0);
        log.info("before update: {}", user);
        user.setName("Updated Name");
        int result = userDao.updateById(user);
        log.info("update result: {}", result);
        User selectedById = userDao.selectById(user.getId());
        log.info("after update: {}", selectedById);
    }

    @Test
    @DisplayName("MyBatis Plus Delete Test")
    public void testDelete() {
        log.info("----- delete method test ------");
        List<User> users = userDao.selectList(null);
        log.info("before delete user list size: {}", users.size());
        User user = users.get(0);
        userDao.deleteById(user.getId());
        log.info("delete user id: {}", user.getId());
        List<User> usersAfterDelete = userDao.selectList(null);
        log.info("after delete user list size: {}", usersAfterDelete.size());
    }
}