基于Mybatis-plus的分页查询

 

 controller层 前端传入的Map集合

    @RequestMapping("/list")
    public BaseResponse list(@RequestParam MapparamMap){
        BaseResponse response=new BaseResponse(StatusCode.Success);
        Map resMap= Maps.newHashMap();
        try{
            PageUtil page=sysPostService.queryPage(paramMap);
            resMap.put("page",page);
        }catch (Exception e){
            response=new BaseResponse(StatusCode.Fail.getCode(),e.getMessage());
        }
        response.setData(resMap);
        return response;
    }

 service接口层：

public interface SysPostService extends IService {}

 service实现层：

@Service
public class SysPostServiceImpl extends ServiceImpl implements SysPostService {}

    @Override
    public PageUtil queryPage(Map params) {
        //拿到检索条件
        String search=(params.get("search")==null)?"":params.get("search").toString();
        //调用自封装的分页查询工具(一页多少，升序降序、当前第几页)返回成Ipage
        IPagequeryPage=new QueryUtil().getQueryPage(params);
        //写查询的Wrapper
        QueryWrapper wrapper=new QueryWrapper()
                .like(StringUtils.isNotBlank(search),"post_code",search.trim())
                .or(StringUtils.isNotBlank(search))
                .like(StringUtils.isNotBlank(search),"post_name",search.trim());
        IPage resPage=this.page(queryPage,wrapper);
        //返回结果重载了泛型
        return new PageUtil(resPage);
    }

 mapper定义：

@Mapper
public interface SysPostDao extends BaseMapper {}

用到的包装类：

PageUtil类，用于包装分页组件，定义了返回前端的内容

package com.qty.common.utils;

import com.baomidou.mybatisplus.core.metadata.IPage;
import lombok.Data;
import lombok.ToString;

import java.io.Serializable;
import java.util.List;

@Data
@ToString
public class PageUtil implements Serializable {
    private static final long serialVersionUID=1L;

    //总记录数
    private int totalCount;

    //每页记录数
    private int pageSize;

    //总页数
    private int totalPage;

    //当前第几页
    private int currPage;

    //列表数据
    private List list;

    public PageUtil(int totalCount, int pageSize, int totalPage, int currPage, List list) {
        this.totalCount = totalCount;
        this.pageSize = pageSize;
        this.totalPage = totalPage;
        this.currPage = currPage;
        this.list = list;
    }

    /**
     * 分页（使用）
     * @param page
     */
    public PageUtil(IPagepage) {
        this.list=page.getRecords();
        this.totalCount= (int) page.getTotal();
        this.pageSize = (int)page.getSize();
        this.currPage = (int)page.getCurrent();
        this.totalPage = (int)page.getPages();
    }
}

QueryUtil类，用于对前端传入的参数二次封装

package com.qty.common.utils;

/**
 * Created by Administrator on 2019/7/18.
 */

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.apache.commons.lang.StringUtils;

import java.util.Map;

/**
 * 查询统一封装的工具类
 * @Author:debug (SteadyJack)
 * @Date: 2019/8/1 22:23
 **/
public class QueryUtil {

    public IPage getQueryPage(Map params) {
        //当前第几页、每页显示的条目
        long curPage = 1;
        long limit = 10;

        if (params.get(Constant.PAGE)!=null){
            curPage=Long.valueOf(params.get(Constant.PAGE).toString());
        }
        if (params.get(Constant.LIMIT)!=null){
            limit=Long.valueOf(params.get(Constant.LIMIT).toString());
        }

        //分页对象
        Page page = new Page<>(curPage, limit);

        //前端请求的字段排序
        if(params.get(Constant.ORDER)!=null && params.get(Constant.ORDER_FIELD)!=null){

            //SQLFilter.sqlInject((String) params.get(Constant.ORDER_FIELD));


            if(Constant.ASC.equalsIgnoreCase(params.get(Constant.ORDER).toString())) {
                return page.setAsc(params.get(Constant.ORDER_FIELD).toString());
            }else {
                return page.setDesc(params.get(Constant.ORDER_FIELD).toString());
            }
        }

        return page;
    }
}

 MybatisConfig 配置类

package com.qty.server.config;

import com.baomidou.mybatisplus.core.injector.ISqlInjector;
import com.baomidou.mybatisplus.extension.injector.LogicSqlInjector;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MybatisPlusConfig {

    /**
     * 分页插件
     * @return
     */
    @Bean
    public PaginationInterceptor paginationInterceptor(){
        return new PaginationInterceptor();
    }

    /**
     * 防Sql注入
     * @return
     */
    @Bean
    public ISqlInjector sqlInjector(){
        return new LogicSqlInjector();
    }
}

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