如何在后端实现导出前端列表字段到Excel功能

需求

根据表格展示的列表字段、点击导出会弹出一个EXCEL包含下列的信息，但是由于框架自带的是Mybatis-plus需要提供的实体类字段和表格中展示的是一样的，因此是行不通的，因为下列的字段和数据库表不能一一对应上，因此考虑自定义封装一个接口

前端的实现

1. 提供一个导出的点击函数

    <!--引用表格-->
    <BasicTable @register="registerTable" :rowSelection="rowSelection">
      <!--插槽:table标题-->
      <template #tableTitle>
        <a-button type="primary" @click="handleAdd" preIcon="ant-design:plus-outlined"> 新增</a-button>
        <a-button  type="primary" preIcon="ant-design:export-outlined" @click="exportXlS"> 导出</a-button>
        <j-upload-button type="primary" preIcon="ant-design:import-outlined" @click="onImportXls">导入</j-upload-button>
        <a-dropdown v-if="selectedRowKeys.length > 0">
          <template #overlay>
            <a-menu>
              <a-menu-item key="1" @click="batchHandleDelete">
                <Icon icon="ant-design:delete-outlined"></Icon>
                删除
              </a-menu-item>
            </a-menu>
          </template>
          <a-button>批量操作
            <Icon icon="mdi:chevron-down"></Icon>
          </a-button>
        </a-dropdown>
      </template>
      <!--操作栏-->
      <template #action="{ record }">
        <TableAction :actions="getTableAction(record)" :dropDownActions="getDropDownAction(record)" />
      </template>
      <!--字段回显插槽-->
      <template #htmlSlot="{ text }">
        <div v-html="text"></div>
      </template>
      <template #bill_data="{ record }"> 
        <!-- 文字提示 -->
        <a-tooltip>
          <template #title>{{ record.bill}}</template> 
          <a-button type="primary" shape="round" @click = "showBillDetails(record.id)">查看</a-button> 
        </a-tooltip>
      </template>
     <!--省市区字段回显插槽-->
      <template #pcaSlot="{ text }">
        {{ getAreaTextByCode(text) }}
      </template>
      <template #fileSlot="{ text }">
        <span v-if="!text" style="font-size: 12px;font-style: italic;">无文件</span>
        <a-button v-else :ghost="true" type="primary" preIcon="ant-design:download-outlined" size="small"
          @click="downloadFile(text)">下载</a-button>
      </template>
    </BasicTable>

2.引入组件中的userMethod

  import { useMethods } from '/@/hooks/system/useMethods';

3.tableProps中导出中添加对应的查询参数

const { prefixCls, tableContext, onExportXls, onImportXls } = useListPage({
  tableProps: {
    title: '数据报表',
    api: queryList,
    columns,
    canResize: false,
    useSearchForm: false,
    showActionColumn: false,
    summaryData: summaryData,
    pagination:false,
    actionColumn: {
      width: 120,
      fixed: 'right',
    },
    beforeFetch: (params) => {
      return Object.assign(params, queryParam.value);
    },afterFetch: (data) =>{
      
    }
  },
  exportConfig: {
    name: "数据报表",
    url: getExportUrl,
    params:queryParam.value
  },
  importConfig: {
    url: getImportUrl,
    success: handleSuccess
  },
});

4. 编写导出函数

  //导入导出方法
 const { handleExportXls, handleImportXls } = useMethods();

  /**
   * 导出事件
   */
  function exportXlS() {
    return handleExportXls("账号数据表", "/count/opReport/exportExcel", queryParam.value);
  }

后端逻辑的实现

1.Controller层

使用ModelAndView进行接收，同时Dto是前端查询的那些参数，ReportAccountModal实体类使我们导出Excel对应的那些字段

	/**@param reportAccountDto
	 * @author chenglin
	 * @description 补充导出Excel功能
	 * @date  16:26 2023/5/30
	 **/
	@RequestMapping(value = "/exportExcel")
	public ModelAndView exportExcel(HttpServletRequest request, ReportAccountDto reportAccountDto) {
		return OpReportAccountService.exportExcel(request,reportAccountDto, ReportAccountModal.class,"账号数据表");
	}

2.创建Modal类

package org.jeecg.modules.count.modal;

import com.fasterxml.jackson.annotation.JsonFormat;
import io.swagger.annotations.ApiModelProperty;
import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;
import lombok.Data;
import org.jeecgframework.poi.excel.annotation.Excel;
import org.springframework.format.annotation.DateTimeFormat;

/**
 * @description: 账号报表EXCEL模型类
 * @author: chenglin
 * @date: 2023年05月30日 16:28
 */
@Data
public class ReportAccountModal implements Serializable {
    private static final long serialVersionUID = 1L;
    /**账号昵称*/
    @Excel(name = "账号昵称", width = 15)
    @ApiModelProperty(value = "账号昵称")
    private String nickName;
    /**账号*/
    @Excel(name = "账号", width = 15)
    @ApiModelProperty(value = "账号")
    private String account;
    /**游戏*/
    @Excel(name = "游戏", width = 15)
    @ApiModelProperty(value = "游戏")
    private String subGameIds;
    /**渠道*/
    @Excel(name = "渠道", width = 15)
    @ApiModelProperty(value = "渠道")
    private String channelName;
    /**投放消耗*/
    @Excel(name = "投放消耗", width = 15)
    @ApiModelProperty(value = "投放消耗")
    private BigDecimal outCostMoney;
    /**账号余额*/
    @Excel(name = "账号余额", width = 15)
    @ApiModelProperty(value = "账号余额")
    private BigDecimal surplusAmount;
    /**曝光*/
    @Excel(name = "曝光", width = 15)
    @ApiModelProperty(value = "曝光")
    private BigDecimal exhibition;
    /**下载*/
    @Excel(name = "下载", width = 15)
    @ApiModelProperty(value = "下载")
    private BigDecimal download ;
    /**负责人*/
    @Excel(name = "负责人", width = 15)
    @ApiModelProperty(value = "负责人")
    private String principalUser;
    /**创建时间*/
    @Excel(name = "创建时间", width = 15)
    @JsonFormat(timezone = "GMT+8",pattern = "yyyy-MM-dd")
    @DateTimeFormat(pattern="yyyy-MM-dd")
    @ApiModelProperty(value = "创建时间")
    private Date createTime;
    /**更新时间*/
    @Excel(name = "更新时间", width = 15)
    @JsonFormat(timezone = "GMT+8",pattern = "yyyy-MM-dd")
    @DateTimeFormat(pattern="yyyy-MM-dd")
    @ApiModelProperty(value = "更新时间")
    private Date updateTime;
}

3.Sevice层

其中我们的这个reusltList是我调用了之前查询数据的接口，然后将对应的数据拷贝到我的Modal类

    ModelAndView exportExcel(HttpServletRequest request, ReportAccountDto reportAccountDto, Class<ReportAccountModal> reportAccountClass, String
        title);

//这是impl
    @Override
    public ModelAndView exportExcel(HttpServletRequest request, ReportAccountDto reportAccountDto,
        Class<ReportAccountModal> reportAccountVoClass, String title) {
        LoginUser sysUser = (LoginUser) SecurityUtils.getSubject().getPrincipal();
        String  username = JwtUtil.getUserNameByToken(request);
        // Step.2 获取导出数据
        List<ReportAccountVo> resultList = queryAccountList(reportAccountDto,username);
        List<ReportAccountModal>exportList = new ArrayList<>();
        for (ReportAccountVo reportAccountVo : resultList) {
            ReportAccountModal reportAccountModal = new ReportAccountModal();
            BeanUtils.copyProperties(reportAccountVo,reportAccountModal);
            exportList.add(reportAccountModal);
        }
        // Step.3 AutoPoi 导出Excel
        ModelAndView mv = new ModelAndView(new JeecgEntityExcelView());
        //此处设置的filename无效 ,前端会重更新设置一下
        mv.addObject(NormalExcelConstants.FILE_NAME, title);
        mv.addObject(NormalExcelConstants.CLASS, reportAccountVoClass);
        //update-begin--Author:liusq  Date:20210126 for：图片导出报错，ImageBasePath未设置--------------------
        ExportParams exportParams=new ExportParams(title + "报表", "导出人:" + sysUser.getRealname(), title);
        exportParams.setImageBasePath(upLoadPath);
        //update-end--Author:liusq  Date:20210126 for：图片导出报错，ImageBasePath未设置----------------------
        mv.addObject(NormalExcelConstants.PARAMS,exportParams);
        mv.addObject(NormalExcelConstants.DATA_LIST, exportList);
        return mv;
    }