SpringBoot整合Mybatis-plus的具体使用
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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;
@Mapper
public 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;
@Service
public 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
1.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
到此这篇关于SpringBoot整合Mybatis-plus的具体使用的文章就介绍到这了,更多相关SpringBoot整合Mybatis-plus 内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！
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