一、mybatisplus是什么？

MyBatis-Plus (opens new window)（简称 MP）是一个 MyBatis (opens new window)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。

二、整合mybatisplus的步骤

1.引入相关jar包

  1.    <dependency>
  2.             <groupId>com.baomidou</groupId>
  3.             <artifactId>mybatis-plus-boot-starter</artifactId>
  4.             <version>3.5.1</version>
  5.         </dependency>

此外还需要引入其他相关jar包

2.完整pom文件内容

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  4.     <modelVersion>4.0.0</modelVersion>
  5.     <parent>
  6.         <groupId>org.springframework.boot</groupId>
  7.         <artifactId>spring-boot-starter-parent</artifactId>
  8.         <version>2.6.3</version>
  9.         <relativePath/> <!-- lookup parent from repository -->
  10.     </parent>
  11.     <groupId>com.example</groupId>
  12.     <artifactId>demo</artifactId>
  13.     <version>0.0.1-SNAPSHOT</version>
  14.     <name>springboot-mybatisplus</name>
  15.     <description>Demo project for Spring Boot</description>
  16.     <properties>
  17.         <java.version>1.8</java.version>
  18.     </properties>
  19.     <dependencies>
  20.         <dependency>
  21.             <groupId>org.springframework.boot</groupId>
  22.             <artifactId>spring-boot-starter-data-jdbc</artifactId>
  23.         </dependency>
  24.         <dependency>
  25.             <groupId>org.springframework.boot</groupId>
  26.             <artifactId>spring-boot-starter-web</artifactId>
  27.         </dependency>
  29.         <dependency>
  30.             <groupId>mysql</groupId>
  31.             <artifactId>mysql-connector-java</artifactId>
  32.             <scope>runtime</scope>
  33.         </dependency>
  34.         <dependency>
  35.             <groupId>org.projectlombok</groupId>
  36.             <artifactId>lombok</artifactId>
  37.             <optional>true</optional>
  38.         </dependency>
  39.         <dependency>
  40.             <groupId>org.springframework.boot</groupId>
  41.             <artifactId>spring-boot-starter-test</artifactId>
  42.             <scope>test</scope>
  43.         </dependency>
  44.         <dependency>
  45.             <groupId>com.baomidou</groupId>
  46.             <artifactId>mybatis-plus-boot-starter</artifactId>
  47.             <version>3.5.1</version>
  48.         </dependency>
  49.     </dependencies>
  51.     <build>
  52.         <plugins>
  53.             <plugin>
  54.                 <groupId>org.springframework.boot</groupId>
  55.                 <artifactId>spring-boot-maven-plugin</artifactId>
  56.                 <configuration>
  57.                     <excludes>
  58.                         <exclude>
  59.                             <groupId>org.projectlombok</groupId>
  60.                             <artifactId>lombok</artifactId>
  61.                         </exclude>
  62.                     </excludes>
  63.                 </configuration>
  64.             </plugin>
  65.         </plugins>
  66.     </build>
  68. </project>

3.application配置文件内容

  1. spring:
  2.   datasource:
  3.     #   数据源基本配置
  4.     username: root
  5.     password: 123456
  6.     driver-class-name: com.mysql.cj.jdbc.Driver
  7.     url: jdbc:mysql://101.34.49.127:3306/springBootAll?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false
  8. # mysql5 不需要声明serverTimezone=GMT%2B8& 时区
  9. # mysql8 需要声明serverTimezone=GMT%2B8& 时区
  13. server:
  14.   port: 8082 # 配置项目启动端口
  15. mybatis-plus:
  16.   configuration:
  17.     log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #控制台打印日志

4.项目主方法内容

  1. @SpringBootApplication
  2. @MapperScan("com.example.demo.dao") //dao接口位置
  3. public class SpringbootMybatisplusApplication {
  5.     public static void main(String[] args) {
  6.         SpringApplication.run(SpringbootMybatisplusApplication.class, args);
  7.     }
  9. }

5.dao接口层内容

  1. //此处继承BaseMapper实现mybatisplus的基础操作
  2. public interface UserDao extends BaseMapper<User> {
  4. }

6.service服务处方法

  1. @Service
  2. public class UserService {
  4.     @Resource
  5.     UserDao userDao;
  7.     public User findUserById(Integer userId){
  8.         return userDao.selectById(userId);
  9.     }
  13.     public List<User> selectUserList(){
  14.         return  userDao.selectList(null);
  15.     }
  17.     public void insertUser(User user){
  18.         userDao.insert(user);
  19.     }
  22.     public void updateUser(User user){
  23.         userDao.updateById(user);
  24.     }
  26.     public List<User> findUserListByQuery(User user){
  27.         //查询条件
  28.         QueryWrapper<User> wrapper = new QueryWrapper<>();
  29.         //模糊查询
  30.         wrapper.like("user_name",user.getUserName());
  31.         wrapper.like("idCardNumber",user.getIdCardNumber());
  33.         return userDao.selectList(wrapper);
  34.     }
  35. }

7.User实体类

  1. @TableName("user")
  2. @Data
  3. public class User {
  5.     @TableId(type = IdType.ASSIGN_ID)
  6.     private Integer id;
  8.     @TableField("user_name")
  9.     private String userName;
  11.     @TableField("idCardNumber")
  12.     private String idCardNumber;
  14.     @TableField("phone_number")
  15.     private String phoneNumber;
  17.     @TableField("dept_id")
  18.     private Integer deptId;
  20.     /**
  21.      * 新增时填入时间
  22.      */
  23.     @TableField(fill = FieldFill.INSERT)
  24.     private Date createTime;
  26.     /**
  27.      * 新增或修改时填入数据
  28.      */
  29.     @TableField(fill = FieldFill.INSERT_UPDATE)
  30.     private Date updateTime;
  31. }

注意:

  1. @KeySequence(value = "SEQ_TEMPLATE_PARAM") 注解中是当主键id的生成策略为序列时使用
  3. @TableFiled(exist = false) 说明此字段不为表中字段

springBoot学习笔记（2.6）——- 整合mybatisPlus - 图1

springBoot学习笔记（2.6）——- 整合mybatisPlus - 图2

8.插件配置类

  1. /**
  2.  * @description:插件配置类
  3.  * @author: xiaYZ
  4.  * @createDate: 2022/2/3
  5.  * @version: 1.0
  6.  */
  7. @Component
  8. public class MyHandle implements MetaObjectHandler {
  10.     /**
  11.      * 新增时填充策略
  12.      */
  13.     @Override
  14.     public void insertFill(MetaObject metaObject) {
  15.         this.setFieldValByName("createTime",new Date(),metaObject);
  16.         this.setFieldValByName("updateTime",new Date(),metaObject);
  17.     }
  20.     /**
  21.      * 修改时填充策略
  22.      */
  23.     @Override
  24.     public void updateFill(MetaObject metaObject) {
  25.         this.setFieldValByName("updateTime",new Date(),metaObject);
  26.     }
  27. }

9. Controller控制层内容

  1. /**
  2.  * @description:
  3.  * @author: xiaYZ
  4.  * @createDate: 2022/2/2
  5.  * @version: 1.0
  6.  */
  7. @Controller
  8. @RequestMapping("userController")
  9. public class UserController {
  11.     @Resource
  12.     UserService userService;
  14.     /***
  15.      * description: findUserById
  16.      * version: 1.0 ->
  17.      * date: 2022/2/2 10:37
  18.      * author: xiaYZ
  19.      * iteration: 迭代说明
  20.      * @param userId
  21.      * @return java.lang.String
  22.      */
  23.     @ResponseBody
  24.     @RequestMapping("findUserById")
  25.     @Description("查询用户信息通过id")
  26.     public String findUserById(Integer userId){
  27.         User user = new User();
  28.         try{
  29.             user = userService.findUserById(userId);
  30.         }catch (Exception e){
  31.             e.printStackTrace();
  32.         }
  33.         return user.toString();
  34.     }
  36.     /***
  37.      * description: insertUser
  38.      * version: 1.0 ->
  39.      * date: 2022/2/3 11:32
  40.      * author: xiaYZ
  41.      * iteration: 迭代说明
  42.      * @param user
  43.      * @return java.lang.String
  44.      */
  45.     @ResponseBody
  46.     @PostMapping("insertUser")
  47.     @Description("新增用户")
  48.     public String insertUser(User user){
  49.         try{
  50.             userService.insertUser(user);
  51.         }catch (Exception e){
  52.             e.printStackTrace();
  53.             return "新增用户失败";
  54.         }
  55.         return "新增用户成功";
  56.     }
  58.     /****
  59.      * description: updateUser
  60.      * version: 1.0 ->
  61.      * date: 2022/2/3 11:54
  62.      * author: xiaYZ
  63.      * iteration: 迭代说明
  64.      * @param user
  65.      * @return java.lang.String
  66.      */
  67.     @ResponseBody
  68.     @PutMapping("updateUser")
  69.     @Description("修改用户")
  70.     public String updateUser(User user){
  71.         try{
  72.             userService.updateUser(user);
  73.         }catch (Exception e){
  74.             e.printStackTrace();
  75.             return "修改用户失败";
  76.         }
  77.         return "修改用户成功";
  78.     }
  80.     /*****
  81.      * description: findUserListByQuery
  82.      * version: 1.0 ->
  83.      * date: 2022/2/7 14:01
  84.      * author: xiaYZ
  85.      * iteration: 迭代说明
  86.      * @param user
  87.      * @return java.util.List<com.example.demo.entity.User>
  88.      */
  89.     @ResponseBody
  90.     @RequestMapping("findUserListByQuery")
  91.     @Description("条件查询")
  92.     public List<User> findUserListByQuery(User user){
  93.         List<User> list = new ArrayList<>();
  94.         try{
  95.             list = userService.findUserListByQuery(user);
  97.         }catch (Exception e){
  98.             e.printStackTrace();
  99.         }
  100.         return list;
  101.     }
  102. }

三、项目运行截图

springBoot学习笔记（2.6）——- 整合mybatisPlus - 图3

总结

  1. 此次项目只是简单的springBoo整合mybatisplus，只涉及简单的CRUD操作
  2. 更多详细功能操作请查询官网mybatisPlus

项目源码