今天小编给大家分享一下SpringBoot整合Mybatis-plus怎么使用的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。
一、mybatis-plus简介：
Mybatis-Plus（简称MP）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。这是官方给的定义，关于mybatis-plus的更多介绍及特性，可以参考mybatis-plus官网。那么它是怎么增强的呢？其实就是它已经封装好了一些crud方法，我们不需要再写xml了，直接调用这些方法就行，就类似于JPA。并且3.X系列支持lambda语法,让我在写条件构造的时候少了很多的"魔法值",从代码结构上更简洁了.
二、springboot整合mybatis-plus案例
pom.xml配置
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <!--springboot程序测试依赖，如果是自动创建项目默认添加--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.16.10</version> <scope>provided</scope> </dependency> <!-- 包含spirng Mvc ,tomcat的包包含requestMapping restController 等注解 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!-- druid依赖 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.1.0</version> </dependency> <!-- mybatisPlus 核心库 --> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.1.0</version> </dependency> </dependencies>application.yml配置
server: port: 10100 # 配置启动端口号 mybatis: config-location: classpath:mybatis.cfg.xml # mybatis主配置文件所在路径 type-aliases-package: com.demo.drools.entity # 定义所有操作类的别名所在包 mapper-locations: # 所有的mapper映射文件 - classpath:mapper@Data@TableName("user_info")//@TableName中的值对应着表名public class UserInfoEntity { @TableId(type = IdType.AUTO) private Long id; private String name; private Integer age; private String skill; private String evaluate; private Long fraction;}config类
package com.demo.drools.config; import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;import com.baomidou.mybatisplus.extension.plugins.PerformanceInterceptor;import org.springframework.context.annotation.Bean; public class MybatisPlusConfig { @Bean public PerformanceInterceptor performanceInterceptor() { return new PerformanceInterceptor(); } @Bean public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); }}spring boot启动类
package com.demo.drools; import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication//@MapperScan和dao层添加@Mapper注解意思一样@MapperScan(basePackages = "com.demo.drools.dao")public class DroolsApplication { public static void main(String[] args) { SpringApplication.run(DroolsApplication.class, args); }}dao层
package com.demo.drools.dao; import com.baomidou.mybatisplus.core.mapper.BaseMapper;import com.baomidou.mybatisplus.core.metadata.IPage;import com.demo.drools.entity.UserInfoEntity;import org.apache.ibatis.annotations.Mapper;import org.apache.ibatis.annotations.Param; @Mapperpublic interface UserInfoDao extends BaseMapper<UserInfoEntity> { }service层
package com.demo.drools.service; import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.service.IService;import com.demo.drools.entity.UserInfoEntity; public interface UserInfoService extends IService<UserInfoEntity> { }serviceImpl实现类层
package com.demo.drools.service.impl; import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;import com.demo.drools.dao.UserInfoDao;import com.demo.drools.entity.UserInfoEntity;import com.demo.drools.service.UserInfoService;import org.springframework.stereotype.Service; import javax.annotation.Resource; @Servicepublic class UserInfoSerivceImpl extends ServiceImpl<UserInfoDao, UserInfoEntity> implements UserInfoService { }controller控制层
package com.demo.drools.controller; import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;import com.demo.drools.entity.UserInfoEntity;import com.demo.drools.service.UserInfoService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController; import java.util.ArrayList;import java.util.Collection;import java.util.HashMap;import java.util.List;import java.util.Map; @RestController@RequestMapping("/userInfo")public class UserInfoController { @Autowired private UserInfoService userInfoService; @RequestMapping("/getInfo") public UserInfoEntity getInfo(String userId){ UserInfoEntity userInfoEntity = userInfoService.getById(userId); return userInfoEntity; } @RequestMapping("/getList") public List<UserInfoEntity> getList(){ List<UserInfoEntity> userInfoEntityList = userInfoService.list(); return userInfoEntityList; } @RequestMapping("/getInfoListPage") public IPage<UserInfoEntity> getInfoListPage(){ //需要在Config配置类中配置分页插件 IPage<UserInfoEntity> page = new Page<>(); page.setCurrent(5); //当前页 page.setSize(1); //每页条数 page = userInfoService.page(page); return page; } @RequestMapping("/getListMap") public Collection<UserInfoEntity> getListMap(){ Map<String,Object> map = new HashMap<>(); //kay是字段名 value是字段值 map.put("age",20); Collection<UserInfoEntity> userInfoEntityList = userInfoService.listByMap(map); return userInfoEntityList; } @RequestMapping("/saveInfo") public void saveInfo(){ UserInfoEntity userInfoEntity = new UserInfoEntity(); userInfoEntity.setName("小龙"); userInfoEntity.setSkill("JAVA"); userInfoEntity.setAge(18); userInfoEntity.setFraction(59L); userInfoEntity.setEvaluate("该学生是一个在改BUG的码农"); userInfoService.save(userInfoEntity); } @RequestMapping("/saveInfoList") public void saveInfoList(){ //创建对象 UserInfoEntity sans = new UserInfoEntity(); sans.setName("Sans"); sans.setSkill("睡觉"); sans.setAge(18); sans.setFraction(60L); sans.setEvaluate("Sans是一个爱睡觉,并且身材较矮骨骼巨大的骷髅小胖子"); UserInfoEntity papyrus = new UserInfoEntity(); papyrus.setName("papyrus"); papyrus.setSkill("JAVA"); papyrus.setAge(18); papyrus.setFraction(58L); papyrus.setEvaluate("Papyrus是一个讲话大声、个性张扬的骷髅，给人自信、有魅力的骷髅小瘦子"); //批量保存 List<UserInfoEntity> list =new ArrayList<>(); list.add(sans); list.add(papyrus); userInfoService.saveBatch(list); } @RequestMapping("/updateInfo") public void updateInfo(){ //根据实体中的ID去更新,其他字段如果值为null则不会更新该字段,参考yml配置文件 UserInfoEntity userInfoEntity = new UserInfoEntity(); userInfoEntity.setId(1L); userInfoEntity.setAge(19); userInfoService.updateById(userInfoEntity); } @RequestMapping("/saveOrUpdateInfo") public void saveOrUpdate(){ //传入的实体类userInfoEntity中ID为null就会新增(ID自增) //实体类ID值存在,如果数据库存在ID就会更新,如果不存在就会新增 UserInfoEntity userInfoEntity = new UserInfoEntity(); userInfoEntity.setId(1L); userInfoEntity.setAge(20); userInfoService.saveOrUpdate(userInfoEntity); } @RequestMapping("/deleteInfo") public void deleteInfo(String userId){ userInfoService.removeById(userId); } @RequestMapping("/deleteInfoList") public void deleteInfoList(){ List<String> userIdlist = new ArrayList<>(); userIdlist.add("12"); userIdlist.add("13"); userInfoService.removeByIds(userIdlist); } @RequestMapping("/deleteInfoMap") public void deleteInfoMap(){ //kay是字段名 value是字段值 Map<String,Object> map = new HashMap<>(); map.put("skill","删除"); map.put("fraction",10L); userInfoService.removeByMap(map); }}controller层用到lambda语法
package com.demo.drools.controller; import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;import com.demo.drools.entity.UserInfoEntity;import com.demo.drools.service.UserInfoService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping; import java.util.HashMap;import java.util.List;import java.util.Map; public class UserInfoPlusController { @Autowired private UserInfoService userInfoService; @RequestMapping("/getInfoListPlus") public Map<String,Object> getInfoListPage(){ //初始化返回类 Map<String,Object> result = new HashMap<>(); //查询年龄等于18岁的学生 //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE age = 18 QueryWrapper<UserInfoEntity> queryWrapper1 = new QueryWrapper<>(); queryWrapper1.lambda().eq(UserInfoEntity::getAge,18); List<UserInfoEntity> userInfoEntityList1 = userInfoService.list(queryWrapper1); result.put("studentAge18",userInfoEntityList1); //查询年龄大于5岁的学生且小于等于18岁的学生 //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE age > 5 AND age <= 18 QueryWrapper<UserInfoEntity> queryWrapper2 = new QueryWrapper<>(); queryWrapper2.lambda().gt(UserInfoEntity::getAge,5); queryWrapper2.lambda().le(UserInfoEntity::getAge,18); List<UserInfoEntity> userInfoEntityList2 = userInfoService.list(queryWrapper2); result.put("studentAge5",userInfoEntityList2); //模糊查询技能字段带有"画"的数据,并按照年龄降序 //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE skill LIKE '%画%' ORDER BY age DESC QueryWrapper<UserInfoEntity> queryWrapper3 = new QueryWrapper<>(); queryWrapper3.lambda().like(UserInfoEntity::getSkill,"画"); queryWrapper3.lambda().orderByDesc(UserInfoEntity::getAge); List<UserInfoEntity> userInfoEntityList3 = userInfoService.list(queryWrapper3); result.put("studentAgeSkill",userInfoEntityList3); //模糊查询名字带有"小"或者年龄大于18的学生 //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE name LIKE '%小%' OR age > 18 QueryWrapper<UserInfoEntity> queryWrapper4 = new QueryWrapper<>(); queryWrapper4.lambda().like(UserInfoEntity::getName,"小"); queryWrapper4.lambda().or().gt(UserInfoEntity::getAge,18); List<UserInfoEntity> userInfoEntityList4 = userInfoService.list(queryWrapper4); result.put("studentOr",userInfoEntityList4); //查询评价不为null的学生,并且分页 //等价SQL: SELECT id,name,age,skill,evaluate,fraction FROM user_info WHERE evaluate IS NOT NULL LIMIT 0,5 IPage<UserInfoEntity> page = new Page<>(); page.setCurrent(1); page.setSize(5); QueryWrapper<UserInfoEntity> queryWrapper5 = new QueryWrapper<>(); queryWrapper5.lambda().isNotNull(UserInfoEntity::getEvaluate); page = userInfoService.page(page,queryWrapper5); result.put("studentPage",page); return result; }}以上就是mybatis-plus的小案例，mybatis-plus它像我之前使用的spring data jpa框架不用写sql语句，就可以实现简单的增删改查、批量操作、分页mybatis-plus功能还是比较强大，能减少我们写很多代码，我个人还是比较喜欢用这个mybatis-plus的
mybatis-plus只是mybatis的增强版，它不影响mybatis的使用，我们可以写我们自定的方法以及sql，接下来我们看一个小案例
dao层新增方法
IPage<UserInfoEntity> selectUserInfoByGtFraction( @Param(value = "page") IPage<UserInfoEntity> page, @Param(value = "fraction")Long fraction);service新增方法
IPage<UserInfoEntity> selectUserInfoByGtFraction(IPage<UserInfoEntity> page,Long fraction);serviceImpl层新增方法
IPage<UserInfoEntity> selectUserInfoByGtFraction(IPage<UserInfoEntity> page,Long fraction);controller层新增方法
@RequestMapping("/getInfoListSQL") public IPage<UserInfoEntity> getInfoListSQL(){ //查询大于60分以上的学生,并且分页 IPage<UserInfoEntity> page = new Page<>(); page.setCurrent(1); page.setSize(5); page = userInfoService.selectUserInfoByGtFraction(page,60L); return page; }配置我们的mybatis的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.demo.drools.dao.UserInfoDao"> <!-- Sans 2019/6/9 14:35 --> <select id="selectUserInfoByGtFraction" resultType="com.demo.drools.entity.UserInfoEntity"> SELECT * FROM user_info WHERE fraction > #{fraction} </select></mapper>以上配置就是我们的mybatis用法。
mybatis plus强大的条件构造器queryWrapper、updateWrapper
QueryWrapper： Entity 对象封装操作类
2.UpdateWrapper ： Update 条件封装，用于Entity对象更新操作
3.条件构造器使用中的各个方法格式和说明
以上就是“SpringBoot整合Mybatis-plus怎么使用”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网行业资讯频道。
