分页在企业级零碎必不可少，特地是早年开发人员，在sql里写limit。起初随着技术不断更新降级，向limit咱们无需手写，能够通过插件来实现，插件实质上就是limit(在查问语句前面增加limit来做分页)。

MyBatis有PageHelper做分页，MyBatis-Plus只需增加一个配置(spring)或配置类批改就能实现分页。

一、配置类(要害是分页插件)

package com.blog.tutorial.config;import com.baomidou.mybatisplus.core.incrementer.IKeyGenerator;import com.baomidou.mybatisplus.extension.incrementer.H2KeyGenerator;import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;/** * @Author: fun * @Description: 分页拦截器 * @Date: 2020/9/10 10:26 * @Version: 1.0.0 */@Configurationpublic class MybatisPlusConfig {    /** * 注入主键生成器 */ @Bean public IKeyGenerator keyGenerator() {        return new H2KeyGenerator();    }    /** * 分页插件 */ @Bean public PaginationInterceptor paginationInterceptor() {        return new PaginationInterceptor();    }}

二、编写DAO和XML

package com.blog.tutorial.dao;import com.baomidou.mybatisplus.core.mapper.BaseMapper;import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;import com.blog.tutorial.entity.Users;import org.springframework.stereotype.Repository;import java.util.List;/** * <p> * Mapper 接口 * </p> * * @author youcong * @since 2020-04-18 */@Repositorypublic interface UsersDao extends BaseMapper<Users> {    IPage<Users> selectPageVo(Page<Users> page);}
<?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.blog.tutorial.dao.UsersDao">    <!-- 通用查问映射后果 --> <resultMap id="BaseResultMap" type="com.blog.tutorial.entity.Users">        <id column="ID" property="id"/>        <result column="user_login" property="userLogin"/>        <result column="user_pass" property="userPass"/>        <result column="user_nicename" property="userNicename"/>        <result column="user_email" property="userEmail"/>        <result column="user_url" property="userUrl"/>        <result column="user_registered" property="userRegistered"/>        <result column="user_activation_key" property="userActivationKey"/>        <result column="user_status" property="userStatus"/>        <result column="display_name" property="displayName"/>    </resultMap>    <!-- 通用查问后果列 --> <sql id="Base_Column_List">        ID AS id, user_login AS userLogin, user_pass AS userPass, user_nicename AS userNicename, user_email AS userEmail, user_url AS userUrl, user_registered AS userRegistered, user_activation_key AS userActivationKey, user_status AS userStatus, display_name AS displayName    </sql>    <!-- 查问用户列表 --> <select id="selectPageVo" resultMap="BaseResultMap">        select        ID,user_login, user_pass, user_nicename, user_email, user_url, user_registered, user_activation_key, user_status, display_name        from        wp_users    </select></mapper>

三、编写service及其实现类

package com.blog.tutorial.service;import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;import com.baomidou.mybatisplus.extension.service.IService;import com.blog.tutorial.entity.Users;/** * @description: * @author: youcong * @time: 2020/11/14 13:26 */public interface UsersService extends IService<Users> {    IPage<Users> selectUserPage(Page<Users> page);}
package com.blog.tutorial.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.blog.tutorial.dao.UsersDao;import com.blog.tutorial.entity.Users;import com.blog.tutorial.service.UsersService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;/** * @description: * @author: youcong * @time: 2020/11/14 13:27 */@Servicepublic class UsersServiceImpl extends ServiceImpl<UsersDao, Users> implements UsersService {    @Autowired private UsersDao usersDao;    @Override public IPage<Users> selectUserPage(Page<Users> page) {        return usersDao.selectPageVo(page);    }}

四、编写Controller

package com.blog.tutorial.controller;import com.baomidou.mybatisplus.core.metadata.IPage;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;import com.blog.tutorial.entity.Users;import com.blog.tutorial.service.UsersService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;import java.util.HashMap;import java.util.List;import java.util.Map;/** * @description: * @author: youcong * @time: 2020/11/14 13:27 */@RestController@RequestMapping("/user")public class UserController {    @Autowired private UsersService usersService;    @GetMapping("/list")    public Map list(@RequestParam Integer pageNum, @RequestParam Integer pageSize) {        Map<String, Object> returnMap = new HashMap<>();        Page<Users> page = new Page<>(pageNum, pageSize);        IPage<Users> data = usersService.selectUserPage(page);        returnMap.put("count", data.getTotal());        returnMap.put("data", data.getRecords());        return returnMap;    }}

五、测试

效果图如下:

数据刚好十条，并且有总条数。

六、总结

本次例子用的是本人写的sql并联合MyBatis-Plus分页插件来实现分页的，实用场景比拟广，通常是多表关联的查问语句等。如果是单表的话，间接用MyBatis-Plus单表自带的分页API即可。