SpringBoot整合MybatisPlus基本的增删改查，保姆级教程
1|0概述
MybatisPlus是国产的第三方插件， 它封装了许多常用的CURDapi，免去了我们写mapper.xml的重复劳动，这里介绍了基本的整合SpringBoot和基础用法。
2|0引入依赖
在项目中pom文件引入mybatisplus和mysql驱动依赖，如下图
com.baomidou
mybatis-plus-boot-starter
3.5.1
mysql
mysql-connector-java
8.0.26
3|0配置连接信息
在项目中application.yaml文件中配置数据库的连接信息
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/didiadmin?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8&nullCatalogMeansCurrent=true
username: root
password: 1234564|0新建两个表
本案例通过一个完整的业务流程来介绍如何使用mybatispuls，首先在数据库中新建两个表，一个是字典类型表sys_dict_type和一个字典数据表sys_dict_data
CREATE TABLE `sys_dict_type` (
`id` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '标识',
`type_name` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '字典类型名称',
`type_code` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '字典类型标识',
`description` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '字典类型描述',
`enable` CHAR (1) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '是否启用',
`create_by` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '创建人ID',
`create_name` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '创建人名称',
`create_time` datetime DEFAULT NULL COMMENT '创建时间',
`update_by` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '修改人ID',
`update_name` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '修改人名称',
`update_time` datetime DEFAULT NULL COMMENT '修改时间',
`remark` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '备注',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = INNODB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = DYNAMIC
CREATE TABLE `sys_dict_data` (
`data_id` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL COMMENT '标识',
`data_label` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '字典标签',
`data_value` CHAR (20) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '字典值',
`type_code` CHAR (20) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '所属类型',
`is_default` CHAR (1) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '是否默认',
`update_by` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '修改人ID',
`update_name` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '修改人名称',
`update_time` datetime DEFAULT NULL COMMENT '修改时间',
`create_by` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '创建人ID',
`create_name` CHAR (19) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '创建人名称',
`create_time` datetime DEFAULT NULL COMMENT '创建时间',
`remark` VARCHAR (255) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '备注',
`enable` CHAR (1) CHARACTER
SET utf8mb4 COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT '是否启用',
PRIMARY KEY (`data_id`) USING BTREE
) ENGINE = INNODB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = DYNAMIC5|0在项目中创建相应的实体类
通过观察SQL语句发现两个表中有很多相同的字段，所有我们把相同的字段抽离出来，放到一个基础的实体类中，其他实体类通过集成方式获取公共的字段。
5|1创建基础实体类
package com.didiplus.common.base;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;
import java.io.Serializable;
import java.time.LocalDateTime;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc: 基 础 实 体 类
*/
@Data
public class BaseDomain implements Serializable {
/**
* 创建时间
*/
@TableField(value = "create_time", fill = FieldFill.INSERT)
private LocalDateTime createTime;
/**
* 创建人
*/
@TableField(value = "create_by", fill = FieldFill.INSERT)
private String createBy;
/**
* 创建人名称
*/
@TableField(value = "create_name", fill = FieldFill.INSERT)
private String createName;
/**
* 修改时间
*/
@TableField(value = "update_time", fill = FieldFill.UPDATE)
private LocalDateTime updateTime;
/**
* 修改人
*/
@TableField(value = "update_by", fill = FieldFill.UPDATE)
private String updateBy;
/**
* 修改人名称
*/
@TableField(value = "update_name", fill = FieldFill.UPDATE)
private String updateName;
/**
* 备注
*/
private String remark;
}@TableField 是mybatisplus中的一个注解，后面会讲解到的。
基础实体类创建好了，接着我们把剩下的两个实体类也一同创建吧。
5|2SysDictType实体类
package com.didiplus.modules.sys.domain;
import com.didiplus.common.base.BaseDomain;
import com.didiplus.common.base.ValidGroup;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import javax.validation.constraints.*;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/25
* Desc: 字典类型领域模型
*/
@Data
@ApiModel(value = "字典类型")
public class SysDictType extends BaseDomain {
/**
* 标识
*/
@Null(groups = ValidGroup.Crud.Create.class)
@NotNull(groups = ValidGroup.Crud.Update.class,message = "字典ID不能为空")
@ApiModelProperty("ID")
private String id;
/**
* 字典名称
*/
@NotBlank(message = "字典名称必填项")
@ApiModelProperty(value = "字典名称",example = "用户ID")
private String typeName;
/**
* 字典类型
*/
@NotBlank(message = "字典编码不能为空")
@ApiModelProperty(value = "字典编码")
private String typeCode;
/**
* 字典描述
*/
@ApiModelProperty(value = "字典描述")
private String description;
/**
* 字典可用状态
*/
@NotBlank(message = "字典状态不能为空")
@ApiModelProperty(value = "字典状态")
private Boolean enable;
}5|3SysDictData实体类
package com.didiplus.modules.sys.domain;
import com.baomidou.mybatisplus.annotation.TableField;
import com.didiplus.common.base.BaseDomain;
import com.didiplus.common.base.ValidGroup;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Null;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc: 字典值领域模型
*/
@Data
public class SysDictData extends BaseDomain {
/**
* id 编号
*/
@Null(groups = ValidGroup.Crud.Create.class)
@NotNull(groups = ValidGroup.Crud.Update.class,message = "字典数据ID不能为空")
@ApiModelProperty("ID")
@TableField(value = "data_id")
private String dataId;
/**
* 字典显示
*/
@NotBlank(message = "字典数据名称必填项")
@ApiModelProperty(value = "字典数据名称")
private String dataLabel;
/**
* 字典值
*/
@NotBlank(message = "字典数据值不能为空")
@ApiModelProperty(value = "字典数据值")
private String dataValue;
/**
* 字典类型
*/
@ApiModelProperty(value = "字典编码")
@NotBlank(message = "字典数据值不能为空")
private String typeCode;
/**
* 是否为默认
*/
@ApiModelProperty(value = "字典编码")
@NotBlank(message = "字典数据值不能为空")
private String isDefault;
/**
* 是否启用
*/
@NotBlank(message = "字典状态不能为空")
@ApiModelProperty(value = "字典数据状态")
private Boolean enable;
}6|0创建DAO继承MybatisPlus增强接口
为两个实体类中分别添加DAO继承MybatisPlus增强接口，这样就可以集成了增删改查的功能了。
6|1SysDictTypeMapper
package com.didiplus.modules.sys.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.didiplus.modules.sys.domain.SysDictType;
import org.apache.ibatis.annotations.Mapper;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc: 字典类型接口
*/
@Mapper
public interface SysDictTypeMapper extends BaseMapper {
} 6|2SysDictDataMapper
package com.didiplus.modules.sys.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.didiplus.modules.sys.domain.SysDictData;
import org.apache.ibatis.annotations.Mapper;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc: 字典数据接口
*/
@Mapper
public interface SysDictDataMapper extends BaseMapper {
} 7|0进一步封装到Service层
7|1定义Service接口中的抽象方法
SysDictDataService
package com.didiplus.modules.sys.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.didiplus.modules.sys.domain.SysDictData;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc:
*/
public interface SysDictDataService extends IService {
} SysDictTypeService
package com.didiplus.modules.sys.service;
import com.baomidou.mybatisplus.extension.service.IService;
import com.didiplus.modules.sys.domain.SysDictType;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc:
*/
public interface SysDictTypeService extends IService {
} 7|2实现Service接口中的方法
SysDictTypeServiceImpl
package com.didiplus.modules.sys.service.impl;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.didiplus.modules.sys.domain.SysDictType;
import com.didiplus.modules.sys.mapper.SysDictTypeMapper;
import com.didiplus.modules.sys.service.SysDictTypeService;
import org.springframework.stereotype.Service;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc:
*/
@Service
public class SysDictTypeServiceImpl extends ServiceImpl implements SysDictTypeService {
} SysDictDataServiceImpl
package com.didiplus.modules.sys.service.impl;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.didiplus.modules.sys.domain.SysDictType;
import com.didiplus.modules.sys.mapper.SysDictTypeMapper;
import com.didiplus.modules.sys.service.SysDictTypeService;
import org.springframework.stereotype.Service;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc:
*/
@Service
public class SysDictTypeServiceImpl extends ServiceImpl implements SysDictTypeService {
} 8|0在控制层上进行增删改查操作
8|1SysDictTypeController
package com.didiplus.modules.sys.controller;
import com.didiplus.common.base.ValidGroup;
import com.didiplus.modules.sys.domain.SysDictType;
import com.didiplus.modules.sys.service.SysDictTypeService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.v3.oas.annotations.parameters.RequestBody;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/25
* Desc: 数据字典控制器
*/
@RestController
@Api(tags = "数据字典")
@RequestMapping("/api/sys/dictType")
public class SysDictTypeController {
@Autowired
SysDictTypeService sysDictTypeService;
@ApiOperation("字典添加")
@PostMapping("/add")
public String add(@Validated(value = ValidGroup.Crud.Create.class) @RequestBody SysDictType sysDictType) {
return sysDictTypeService.save(sysDictType)? "添加成功":"添加失败";
}
@ApiOperation("字典修改")
@PutMapping("/edit")
public String edit(@Validated(value = ValidGroup.Crud.Update.class) @RequestBody SysDictType sysDictType) {
return sysDictTypeService.updateById(sysDictType)? "修改成功":"修改失败";
}
@ApiOperation("字典删除")
@DeleteMapping("/del/{id}")
public String del( @PathVariable String id) {
return sysDictTypeService.removeById(id)? "删除成功":"删除失败";
}
}体验效果
新增数据
修改数据
删除数据
9|0自动填充功能
原理:
- 实现元对象处理器接口：com.baomidou.mybatisplus.core.handlers.MetaObjectHandler
- 注解填充字段 @TableField(.. fill = FieldFill.INSERT) 生成器策略部分也可以配置！
9|1自定义实现类 DomainInterceptor
package com.didiplus.common.web.interceptor;
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;
import java.time.LocalDateTime;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/5/4
* Desc: 字 段 填 充 拦 截 器
*/
@Component
public class DomainInterceptor implements MetaObjectHandler {
@Override
public void insertFill(MetaObject metaObject) {
createField(metaObject);
}
@Override
public void updateFill(MetaObject metaObject) {
updateField(metaObject);
}
/**
* @Field 创建时间
* */
public void createField(MetaObject metaObject){
this.strictInsertFill(metaObject,"createTime", LocalDateTime.class,LocalDateTime.now());
}
/**
* @Field 修改时间
* */
public void updateField(MetaObject metaObject) {
this.strictUpdateFill(metaObject,"updateTime",LocalDateTime.class,LocalDateTime.now());
}
}10|0分页查询
10|1添加分页插件
package com.didiplus.common.config;
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/5/4
* Desc: mybatis-plus分页插件
*/
@Configuration
public class MyBatisPlusConfig {
/**
* mybatis-plus分页插件
*/
@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
return interceptor;
}
}10|2定义分页接口
package com.didiplus.modules.sys.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.IService;
import com.didiplus.common.web.domain.PageDomain;
import com.didiplus.modules.sys.domain.SysDictType;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc: 数据字典类型服务类
*/
public interface SysDictTypeService extends IService {
IPage page(PageDomain pageDomain);
} 10|3实现分页接口
package com.didiplus.modules.sys.service.impl;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.didiplus.common.web.domain.PageDomain;
import com.didiplus.modules.sys.domain.SysDictType;
import com.didiplus.modules.sys.mapper.SysDictTypeMapper;
import com.didiplus.modules.sys.service.SysDictTypeService;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/4/29
* Desc:
*/
@Service
public class SysDictTypeServiceImpl extends ServiceImpl implements SysDictTypeService {
@Resource
SysDictTypeMapper sysDictTypeMapper;
@Override
public IPage page(PageDomain pageDomain) {
IPage page = new Page<>(pageDomain.getPage(),pageDomain.getLimit());
return sysDictTypeMapper.selectPage(page,null);
}
} 10|4控制层调用
@RestController
@Api(tags = "数据字典")
@RequestMapping("/api/sys/dictType")
public class SysDictTypeController {
@Autowired
SysDictTypeService sysDictTypeService;
@ApiOperation("字典分页查询")
@GetMapping
public IPage list(@RequestBody PageDomain pageDomain){
return sysDictTypeService.page(pageDomain);
}
}PageDomain定义了分页接收的两个参数
PageDomain类
package com.didiplus.common.web.domain;
import lombok.Data;
/**
* Author: didiplus
* Email: [email protected]
* CreateTime: 2022/5/4
* Desc: 分 页 参 数 封 装
*/
@Data
public class PageDomain {
/**
* 当前页
*/
private Integer page;
/**
* 每页数量
*/
private Integer limit;
}10|5体验效果
下一篇，我们继续来学习mybatisPlus的代码生成器