FastExcel 合并单元格（相当的行数据，进行合并）

目录

• 需求
• 思路
• 实现
  • Excel导出单元格全量合并策略
  • 日期格式转换
  • 接口代码
  • Service
  • DTO

使用FastExcel数据导出：官网： https://idev.cn/fastexcel/zh-CN

需求

信用代码、填报人，唯一时，将：信用代码、单位名称、填报人，进行 row 合并，并垂直居中对齐

思路

这边不需要做列合并，所以采用了 RowWriteHandler
思路，

• 指定唯一值，根据某个或多个单元格确定相当的数据行（代码中的 ExcelCellMergeStrategy. uniqueCol）
• 判断当前行的唯一列的数据和上一行是否相等，如果相等继续，要合并的行数 mergeCount + 1
• 如果当前行和上一行不相等，说明前面的数据需要做合并处理了。同时将当前行做为下一次待合并的起始行

实现

Excel导出单元格全量合并策略

package com.vipsoft.handler;import cn.idev.excel.write.handler.RowWriteHandler;
import cn.idev.excel.write.metadata.holder.WriteSheetHolder;
import cn.idev.excel.write.metadata.holder.WriteTableHolder;import org.apache.poi.ss.usermodel.*;import org.apache.poi.ss.util.CellRangeAddress;import java.util.ArrayList;
import java.util.List;/*** Excel导出单元格全量合并策略*/
public class ExcelCellMergeStrategy implements RowWriteHandler {private int mergeRowIndex;//从哪一行开始合并private List<Integer> mergeColumnIndex = new ArrayList<>();//excel合并的列private int[] uniqueCol;//合并的唯一标识，根据指定的列，确定数据是否相同private int totalRow;//总行数private int lastRow;private int firstCol;private int lastCol;private int firstRow;private int mergeCount = 1;/*** @param mergeRowIndex* @param mergeColIndex 支持范围如：0-3,6,9* @param uniqueCol     唯一标识，1列或多列 数据组成唯一值* @param totalRow      总行数(从0开始）：List.size -1  + 跳过的表头*/public ExcelCellMergeStrategy(int mergeRowIndex, Object[] mergeColIndex, int[] uniqueCol, int totalRow) {this.mergeRowIndex = mergeRowIndex;for (Object item : mergeColIndex) {if (item.toString().contains("-")) {String[] spCol = item.toString().split("-");int start = Integer.parseInt(spCol[0]);int end = Integer.parseInt(spCol[1]);for (int i = start; i <= end; i++) {mergeColumnIndex.add(i);}} else {int colIndex = Integer.parseInt(item.toString());mergeColumnIndex.add(colIndex);}}this.uniqueCol = uniqueCol;this.totalRow = totalRow;}@Overridepublic void beforeRowCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Integer rowIndex, Integer relativeRowIndex, Boolean isHead) {}@Overridepublic void afterRowCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {}@Overridepublic void afterRowDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {//当前行int curRowIndex = row.getRowNum();//每一行的最大列数short lastCellNum = row.getLastCellNum();//当前行为开始合并行时，标记if (curRowIndex == mergeRowIndex) {//赋初值 第一行firstRow = curRowIndex;}//开始合并位置if (curRowIndex > mergeRowIndex && !row.getCell(0).getStringCellValue().equals("")) {for (int i = 0; i < lastCellNum; i++) {if (mergeColumnIndex.contains(i)) {//当前行号 当前行对象 合并的标识位mergeWithPrevAnyRow(writeSheetHolder.getSheet(), curRowIndex, row, uniqueCol);break;//已经进入到合并单元格操作里面了，执行一次就行}}}}public void mergeWithPrevAnyRow(Sheet sheet, int curRowIndex, Row row, int[] uniqueCol) {Object currentData = "";Object preData = "";for (int col : uniqueCol) {currentData = currentData + row.getCell(col).getStringCellValue();Row preRow = row.getSheet().getRow(curRowIndex - 1);preData = preData + preRow.getCell(col).getStringCellValue();}//判断是否合并单元格boolean curEqualsPre = currentData.equals(preData);//判断前一个和后一个相同 并且 标识位相同if (curEqualsPre) {lastRow = curRowIndex;mergeCount++;}//excel过程中合并if (!curEqualsPre && mergeCount > 1) {mergeSheet(firstRow, lastRow, mergeColumnIndex, sheet);mergeCount = 1;}//excel结尾处合并if (mergeCount > 1 && totalRow == curRowIndex) {mergeSheet(firstRow, lastRow, mergeColumnIndex, sheet);mergeCount = 1;}//重置下一个要合并的行if (!curEqualsPre) {firstRow = curRowIndex;}}private void mergeSheet(int firstRow, int lastRow, List<Integer> mergeColumnIndex, Sheet sheet) {for (int colNum : mergeColumnIndex) {firstCol = colNum;lastCol = colNum;CellRangeAddress cellRangeAddress = new CellRangeAddress(firstRow, lastRow, firstCol, lastCol);sheet.addMergedRegion(cellRangeAddress);// 设置合并后的单元格样式为垂直居中CellStyle style = sheet.getWorkbook().createCellStyle();style.setVerticalAlignment(VerticalAlignment.CENTER);//style.setAlignment(HorizontalAlignment.CENTER);Cell mergedCell = sheet.getRow(firstRow).getCell(colNum, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);mergedCell.setCellStyle(style);}}
}

日期格式转换

EasyExcel => FastExcel ，导入支持多种时间格式

package com.vipsoft.base.util;import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;import cn.idev.excel.converters.Converter;
import cn.idev.excel.enums.CellDataTypeEnum;
import cn.idev.excel.metadata.GlobalConfiguration;
import cn.idev.excel.metadata.data.ReadCellData;
import cn.idev.excel.metadata.data.WriteCellData;
import cn.idev.excel.metadata.property.ExcelContentProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;/*** 日期格式转换器*/
public class ExcelDateConverter implements Converter<Date> {private static final Logger log = LoggerFactory.getLogger(ExcelDateConverter.class);// 定义所有要尝试的日期格式SimpleDateFormat[] formats = {new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"),new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"),new SimpleDateFormat("yyyy/MM/dd"),new SimpleDateFormat("yyyy-MM-dd"),new SimpleDateFormat("yyyy-MM"),new SimpleDateFormat("yyyy/MM"),new SimpleDateFormat("yyyyMMdd")};@Overridepublic Class<Date> supportJavaTypeKey() {return Date.class;}@Overridepublic CellDataTypeEnum supportExcelTypeKey() {return CellDataTypeEnum.STRING;}@Overridepublic Date convertToJavaData(ReadCellData<?> cellData, ExcelContentProperty contentProperty,GlobalConfiguration globalConfiguration) throws Exception {String cellValue = "";if (cellData.getType().equals(CellDataTypeEnum.NUMBER)) {long cellIntValue = cellData.getNumberValue().longValue();if (cellIntValue > 19900100) {try {// 1. 第一种解析，传入的是数字形式的日期，形如yyyyMMddSimpleDateFormat originalFormat = new SimpleDateFormat("yyyyMMdd");return originalFormat.parse(String.valueOf(cellIntValue));} catch (Exception e) {log.warn("exception when parse numerical time with format yyyyMMdd");cellValue=String.valueOf(cellIntValue);}}// 2. 第二种解析， excel是从1900年开始计算,最终通过计算与1900年间隔的天数计算目标日期LocalDate localDate = LocalDate.of(1900, 1, 1);//excel 有些奇怪的bug, 导致日期数差2localDate = localDate.plusDays(cellIntValue - 2);// 转换为ZonedDateTime（如果需要时区信息）ZonedDateTime zonedDateTime = localDate.atStartOfDay(ZoneId.systemDefault());return Date.from(zonedDateTime.toInstant());} else if (cellData.getType().equals(CellDataTypeEnum.STRING)) {// 3. 第三种解析Date date = null;cellValue = cellData.getStringValue();for (SimpleDateFormat format : formats) {try {date = format.parse(cellValue);if (date != null) {// 这一步是将日期格式化为Java期望的格式return date;}} catch (Exception e) {// 如果有异常，捕捉异常后继续解析//log.error(e.getMessage(), e);}}}// 没转成功，抛出异常throw new UnsupportedOperationException("The current operation is not supported by the current converter." + cellValue);}@Overridepublic WriteCellData<?> convertToExcelData(Date value, ExcelContentProperty contentProperty, GlobalConfiguration globalConfiguration) throws Exception {SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");String dateValue = sdf.format(value);return new WriteCellData<>(dateValue);}
} 

接口代码

导出代码

package com.vipsoft.api.controller;import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.util.Map;/*** 企业信息*/
@RestController
@RequestMapping("/detail")
public class CooperationDetailController extends BaseController {/*** 企业信息* * @return*/@PostMapping("/export")public void exportInfo(HttpServletRequest request, HttpServletResponse response, @RequestBody Map<String, Object> param) {try {Page page = buildPage(param, CooperationInfo.class);QueryWrapper<SysOrganization> queryWrapper = buildQueryWrapper(SysOrganization.class, param);            cooperationDetailService.exportInfo(response, queryWrapper);} catch (Exception ex) {logger.error(ex.getMessage(), ex);}}
}

Service

@Service
public class SysOrganizationServiceImpl extends ServiceImpl<SysOrganizationMapper, SysOrganization> implements ISysOrganizationService {@Overridepublic void exportInfo(HttpServletResponse response, QueryWrapper<SysOrganization> queryWrapper) {String templateFileName = "";try {templateFileName = cuworConfig.getFilePath() + "/template/企业导出模板.xlsx";response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");response.setCharacterEncoding("utf-8");// 这里URLEncoder.encode可以防止中文乱码 当然和 FastExcel 没有关系String fileName = URLEncoder.encode("企业数据", "UTF-8").replaceAll("\\+", "%20");response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");//获取要导出的数据 DTOList<SysOrganizationExcelDTO> dataList = data(queryWrapper);int mergeRowIndex = 2;                      // 从那一行开始合并  -- 跳过表头int[] uniqueCol = {0, 7};                  //根据指定的列，确定相同的数据Object[] mergeColIndex = {"0-1", 6, 7};    //需要合并的列int totalRow = dataList.size() - 1 + mergeRowIndex;// 这里需要设置不关闭流ExcelCellMergeStrategy excelCellMergeStrategy = new ExcelCellMergeStrategy(mergeRowIndex, mergeColIndex, uniqueCol, totalRow);FastExcel.write(response.getOutputStream(), SysOrganizationExcelDTO.class).needHead(false).withTemplate(templateFileName).autoCloseStream(Boolean.FALSE).registerWriteHandler(excelCellMergeStrategy) //合并单元格.sheet("企业数据").doWrite(dataList);} catch (Exception e) {// 重置responseresponse.reset();response.setContentType("application/json");response.setCharacterEncoding("utf-8");//异常时，向前端抛出 JSON ApiResult result = new ApiResult(6001, "下载文件失败 " + templateFileName + " " + e.getMessage());try {response.getWriter().println(PojoUtil.pojoToJson(result));} catch (IOException ex) {logger.error(ex.getMessage(), ex);throw new CustomException(ex.getMessage());}}}/*** 获得要到出的数据*/private List<SysOrganizationExcelDTO> data(QueryWrapper<SysOrganization>  queryWrapper) {IPage list = this.page(new Page(1, 10000), queryWrapper);List<SysOrganizationExcelDTO> result = new ArrayList<>();for (Object obj : list.getRecords()) {if (obj instanceof SysOrganization) {SysOrganization item = (SysOrganization) obj;SysOrganizationExcelDTO info = new SysOrganizationExcelDTO(); BeanUtils.copyProperties(item, info); //组装数据result.add(info);}}return result;}
}  

DTO

package com.vipsoft.base.dto;import cn.idev.excel.annotation.ExcelIgnore;
import cn.idev.excel.annotation.ExcelProperty;
import cn.idev.excel.annotation.format.DateTimeFormat;
import com.vipsoft.base.util.ExcelDateConverter;import java.io.Serializable;
import java.util.Date;/*** Excel 导出使用*/
public class SysOrganizationExcelDTO implements Serializable {/*** 统一社会信用代码*///@ExcelProperty(value = "统一社会信用代码")@ExcelProperty(index = 0)private String unifiedSocialCode;/*** 机构名称*/@ExcelProperty(index = 1)private String orgName; /*** 岗位大类名称*/@ExcelProperty(index = 2)private String jobBigName;/*** 岗位中类名称*/@ExcelProperty(index = 3)private String jobMiddleName;/*** 岗位小类名称*/@ExcelProperty(index = 4)private String jobSmallName;/*** 岗位数量*/@ExcelProperty(index = 5)private Integer jobQty;/*** 填报日期**/@ExcelProperty(index = 6, converter = ExcelDateConverter.class)private Date inputDate;/*** 填报人*/@ExcelProperty(index = 7)private String inputUser;......省略get set}