4.配置启动类

二、使用MP#xff08;mybatisplus#xff09;的分页插件

二、使…结构

xmlnshttp://maven.apache.org/POM/4.0.0xmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://maven.apache.org/POM/4.0.0

http://maven.apache.org/xsd/maven-4.0.0.xsdmodelVersion4.0.0/modelVersiongroupIdcom.qcby/groupIdartifactIdSpringBootMybatisPlus/artifactIdversion1.0-SNAPSHOT/versionparentgroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-parent/artifactIdversion2.4.0/versionrelativePath/

!--

--/parentdependenciesdependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-test/artifactIdscopetest/scope/dependencydependencygroupIdcom.baomidou/groupIdartifactIdmybatis-plus-boot-starter/artifactIdversion3.5.1/version/dependencydependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdoptionaltrue/optional/dependencydependencygroupIdmysql/groupIdartifactIdmysql-connector-java/artifactIdversion5.1.46/versionscoperuntime/scope/dependency/dependenciesbuildpluginsplugingroupIdorg.springframework.boot/groupIdartifactIdspring-boot-maven-plugin/artifactId/plugin/plugins/build/project

4.配置启动类

org.mybatis.spring.annotation.MapperScan;

import

org.springframework.boot.SpringApplication;

import

org.springframework.boot.autoconfigure.SpringBootApplication;SpringBootApplication

MapperScan(com.qcby.SpringBoot.mapper)

public

{SpringApplication.run(SpringBootApplication1.class,

args);}

com.qcby.SpringBoot.pojo;import

com.baomidou.mybatisplus.annotation.TableName;

import

com.qcby.SpringBoot.pojo;import

com.baomidou.mybatisplus.annotation.TableId;

import

com.baomidou.mybatisplus.annotation.TableLogic;

import

com.baomidou.mybatisplus.annotation.TableName;

import

{//因为用到雪花算法所以用Long属性TableIdprivate

Long

com.qcby.SpringBoot.service;import

com.baomidou.mybatisplus.extension.service.IService;

import

com.qcby.SpringBoot.pojo.User;/***

UserService继承IService模板提供的基础功能*/

public

com.qcby.SpringBoot.service.Impl;import

com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

import

com.qcby.SpringBoot.mapper.UserMapper;

import

com.qcby.SpringBoot.service.UserService;

import

org.springframework.stereotype.Service;/***

ServiceImpl实现了IService提供了IService中基础功能的实现*

若ServiceImpl无法满足业务需求则可以使用自定的UserService定义方法并在实现类中实现*/

Service

com.qcby.SpringBoot.mapper;import

com.baomidou.mybatisplus.core.mapper.BaseMapper;

import

com.baomidou.mybatisplus.core.metadata.IPage;

import

com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import

org.apache.ibatis.annotations.Mapper;

import

org.apache.ibatis.annotations.Param;

import

org.apache.ibatis.annotations.Select;Mapper

public

com.qcby.SpringBoot.mapper;import

com.baomidou.mybatisplus.core.mapper.BaseMapper;

import

com.qcby.SpringBoot.pojo.Product;

import

org.apache.ibatis.annotations.Mapper;Mapper

public

com.zaxxer.hikari.HikariDataSource#

jdbc:mysql://localhost:3306/mybatis_plus?characterEncodingutf-8useSSLfalseusername:

rootpassword:

mybatis-plus:configuration:log-impl:

org.apache.ibatis.logging.stdout.StdOutImpl

8.创建数据库表

首先要在容器中配置一个mybatisplus分页插件的bean。

可以自定义一个配置类也可以在启动类中配置因为启动类也是一个配置类。

package

com.qcby.SpringBoot.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;Configuration

public

每个数据库厂商对于分页的实现语法有差别因此在声明该拦截时需要指定应用的数据库类型*

return*/Beanpublic

MybatisPlusInterceptor();interceptor.addInnerInterceptor(newPaginationInnerInterceptor(DbType.MYSQL));//由于各个数据库的语法会有差别因此要指明数据库类型return

interceptor;}

com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import

com.qcby.SpringBoot.mapper.ProductMapper;

import

com.qcby.SpringBoot.mapper.UserMapper;

import

com.qcby.SpringBoot.pojo.Product;

import

org.springframework.beans.factory.annotation.Autowired;

import

org.springframework.boot.test.context.SpringBootTest;import

public

page.getRecords();list.forEach(System.out::println);System.out.println(当前页page.getCurrent());System.out.println(每页显示的条数page.getSize());System.out.println(总记录数page.getTotal());System.out.println(总页数page.getPages());System.out.println(是否有上一页page.hasPrevious());System.out.println(是否有下一页page.hasNext());}}二、使用自定义的分页插件

在usermapper中加入方法

com.qcby.SpringBoot.mapper;import

com.baomidou.mybatisplus.core.mapper.BaseMapper;

import

com.baomidou.mybatisplus.core.metadata.IPage;

import

com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import

org.apache.ibatis.annotations.Mapper;

import

org.apache.ibatis.annotations.Param;

import

org.apache.ibatis.annotations.Select;Mapper

public

不用加limit语句因为配置了一个拦截的插件只需要传入page对象还是使用的MP的分页插件*

param

com.baomidou.mybatisplus.extension.plugins.pagination.Page;

import

com.qcby.SpringBoot.mapper.ProductMapper;

import

com.qcby.SpringBoot.mapper.UserMapper;

import

com.qcby.SpringBoot.pojo.Product;

import

org.springframework.beans.factory.annotation.Autowired;

import

org.springframework.boot.test.context.SpringBootTest;import

public

testSelectPageVo(){//设置分页参数PageUser

page

5);userMapper.selectPageVo(page,

20);//获取分页数据ListUser

page.getRecords();list.forEach(System.out::println);System.out.println(当前页page.getCurrent());System.out.println(每页显示的条数page.getSize());System.out.println(总记录数page.getTotal());System.out.println(总页数page.getPages());System.out.println(是否有上一页page.hasPrevious());System.out.println(是否有下一页page.hasNext());}