一。情景描述

最近在项目中客户提到一个新的需求，一开始是在列表查询时导出多个Excel表格，后面提到将多个Excel表格进行合并，实现一个sheet显示多个sheet内容，图示如下：

一开始：

合并后（不同表格空一行隔开）：

二。实现思路

首先，先按照生成五张表的思路来生成创建一个Workbook sourceWorkbook,然后再创建一个Workbook targetWorkbook，创建一个新的Sheet targetSheet工作表，之后将sourceWorkbook中第一个Sheet sheet1中的内容复制到该表中，再将第二个Sheet sheet2中的内容复制到targetSheet中，依次操作，复制完sourceWorkbook中全部的五张表，即可实现将多个Sheet合并为一个Sheet的操作。

三。示例代码

1.POIUtil工具类

package com.cdtye.itps.jjxt.model.util;
import com.cdtye.itps.jjxt.model.excel.CellRangeAddressExcelVo;
import org.apache.poi.ss.usermodel.*;
import org.springframework.util.CollectionUtils;

import java.util.List;

/**
 * @Author Zhongks
 * @Description //TODO POI导出excel工具类
 * @Date 17:16 2021/5/11
 * @Param
 * @return
 **/
public class POIUtil {
    /**
     * @Author Zhongks
     * @Description //TODO 拷贝sheet（表）
     * @Date 17:16 2021/5/11
     * @Param [targetSheet, sourceSheet, targetWork, sourceWork, startRow, cellRangeAddressExcelVoList]
     * @return void
     **/
    public static void copySheet(Sheet targetSheet, Sheet sourceSheet,
                                 Workbook targetWork, Workbook sourceWork, int startRow,
                                 List<CellRangeAddressExcelVo> cellRangeAddressExcelVoList) {
        if(targetSheet == null || sourceSheet == null || targetWork == null || sourceWork == null){
            throw new IllegalArgumentException("调用PoiUtil.copySheet()方法时，targetSheet、sourceSheet、targetWork、sourceWork都不能为空，故抛出该异常！");
        }

        //设置单元格默认宽度
        targetSheet.setDefaultColumnWidth(25);
        //复制源表中的行
        for (int i = sourceSheet.getFirstRowNum(); i <= sourceSheet.getLastRowNum(); i++) {
            Row sourceRow = sourceSheet.getRow(i);
            Row targetRow = targetSheet.createRow(i+startRow);  //创建新的row
            if (sourceRow != null) {
                copyRow(targetRow, sourceRow,
                        targetWork, sourceWork);
            }
        }

        //自定义合并单元格样式（若不需要进行单元格合并操作，将cellRangeAddressExcelVoList赋值为null即可）
        if(!CollectionUtils.isEmpty(cellRangeAddressExcelVoList)){
            //合并单元格
            for(CellRangeAddressExcelVo model:cellRangeAddressExcelVoList){
                targetSheet.addMergedRegion(new org.apache.poi.ss.util.CellRangeAddress(model.getFirstRow(),model.getLastRow(),model.getFirstCol(),model.getLastCol()));
            }
        }
    }


    /**
     * @Author Zhongks
     * @Description //TODO 拷贝row(行)
     * @Date 17:17 2021/5/11
     * @Param [targetRow, sourceRow, targetWork, sourceWork]
     * @return void
     **/
    public static void copyRow(Row targetRow, Row sourceRow,
                               Workbook targetWork, Workbook sourceWork)  {
        if(targetRow == null || sourceRow == null || targetWork == null || sourceWork == null ){
            throw new IllegalArgumentException("调用PoiUtil.copyRow()方法时，targetRow、sourceRow、targetWork、sourceWork、targetPatriarch都不能为空，故抛出该异常！");
        }

        //设置行高
        targetRow.setHeight(sourceRow.getHeight());

        for (int i = sourceRow.getFirstCellNum(); i < sourceRow.getLastCellNum(); i++) {
            Cell sourceCell = sourceRow.getCell(i);
            Cell targetCell = null;

            if (sourceCell != null && sourceCell.getStringCellValue()!="") {
                if (targetCell == null) {
                    targetCell = targetRow.createCell(i);
                }
                //拷贝单元格，包括内容和样式
                copyCell(targetCell, sourceCell, targetWork, sourceWork);
            }
        }
    }

    /**
     * @Author Zhongks
     * @Description //TODO 拷贝cell（单元格）
     * @Date 17:18 2021/5/11
     * @Param [targetCell, sourceCell, targetWork, sourceWork]
     * @return void
     **/
    public static void copyCell(Cell targetCell, Cell sourceCell, Workbook targetWork, Workbook sourceWork) {
        if(targetCell == null || sourceCell == null || targetWork == null || sourceWork == null ){
            throw new IllegalArgumentException("调用PoiUtil.copyCell()方法时，targetCell、sourceCell、targetWork、sourceWork都不能为空，故抛出该异常！");
        }

        CellStyle targetCellStyle=targetWork.createCellStyle();
        targetCellStyle.cloneStyleFrom(sourceCell.getCellStyle());//拷贝样式
        //重新添加样式（这里可以根据你的需要重新进行单元格样式添加）
        /*targetCellStyle.setBorderTop(BorderStyle.THIN);//设置上边框线
        targetCellStyle.setBorderLeft(BorderStyle.THIN);//设置左边框线
        targetCellStyle.setBorderBottom(BorderStyle.THIN);//设置下边框线
        targetCellStyle.setBorderRight(BorderStyle.THIN);//设置右边框线*/
        targetCell.setCellStyle(targetCellStyle);

        targetCell.setCellValue(sourceCell.getStringCellValue());
    }

}

2.需要合并的单元格位置信息实体

package com.cdtye.itps.jjxt.model.excel;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.experimental.Accessors;

/**
 * @ClassName CellRangeAddressExcelVo
 * @Description TODO 需要合并的单元格位置信息Vo
 * @Author Zhongks
 * @Date 2021/5/11  14:09
 * @Version 1.0
 **/
@Data
@Accessors(chain = true)
@AllArgsConstructor
public class CellRangeAddressExcelVo {
    //起始行号
    private int firstRow;
    //终止行号
    private int lastRow;
    //起始列号
    private int firstCol;
    //终止列号
    private int lastCol;

}

该实体类是为了进行合并单元格操作，用来存储需要合并的单元格位置信息：

Service层代码：

*
     * @Author Zhongks
     * @Description //TODO excel导出
     * @Date 12:25 2021/5/7
     * @Param [list, response]
     * @return void
     **/
    public void export(BureauDayShiftVo bureauDayShiftVo,HttpServletResponse response) {
        try {
            // 设置下载的Excel名称，以当前时间为文件后缀，
            String dateTime = DateUtil.formatDateString(new Date(), DateUtil.DATE_FORMAT);
            String fileName = "供电安全质量日交班表"+dateTime+".xlsx";
            // 设置响应输出的头类型
            response.setHeader("content-Type", "application/vnd.ms-excel");
            response.setHeader("Content-Disposition", "attachment;filename="+fileName);

            // excel信息部分
            //供电处重点信息追踪表信息
            bureauDayShiftVo.setTrackFlag(1);
            Map<String, Object> trackSafeQualityMap =this.getTrackSafeQualityMap(bureauDayShiftVo);
            //日安全质量信息表信息
            bureauDayShiftVo.setTrackFlag(0);
            Map<String, Object> safeQualityParamsMap =this.getTrackSafeQualityMap(bureauDayShiftVo);
            //天窗兑现统计表
            Map<String, Object> skylightCashStatisticsMap = this.getSkylightCashStatisticsMap();
            //其他安全质量信息表
            Map<String, Object> otherSafeQualityInfoMap = this.getOtherSafeQualityInfoMap(bureauDayShiftVo);
            //安全质量考核表
            Map<String, Object> safeQualityAssessmentMap = this.getSafeQualityAssessmentMap();

            //添加表
            List<Map<String, Object>> sheetsList = new ArrayList<>();
            sheetsList.add(trackSafeQualityMap);
            sheetsList.add(safeQualityParamsMap);
            sheetsList.add(skylightCashStatisticsMap);
            sheetsList.add(otherSafeQualityInfoMap);
            sheetsList.add(safeQualityAssessmentMap);

            List<Map<String, Object>> sourceSheetsList = new ArrayList<>();

            //创建excel文件的方法
            Workbook sourceWorkbook = ExcelExportUtil.exportExcel(sheetsList, ExcelType.HSSF);
            Workbook targetWorkbook = ExcelExportUtil.exportExcel(sourceSheetsList, ExcelType.HSSF);
            Workbook workbook = this.mergeWorkSheet(targetWorkbook, sourceWorkbook);
            //通过response输出流直接输入给客户端
            ServletOutputStream outputStream = response.getOutputStream();
            workbook.write(outputStream);
            outputStream.flush();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    /**
     * @Author Zhongks
     * @Description //TODO 返回重点追踪以及非重点追踪excel信息
     * @Date 9:31 2021/5/8
     * @Param [bureauDayShiftVo]
     * @return java.util.List<java.util.Map<java.lang.String,java.lang.Object>>
     **/
    public Map<String, Object> getTrackSafeQualityMap(BureauDayShiftVo bureauDayShiftVo){
        List<BureauDayShiftExcelVo> exportList = new LinkedList<>();
        List<Map<String, Object>> allTrackSafeQualityList = this.getAllTrackSafeQualityList(bureauDayShiftVo);
        //封装数据
        allTrackSafeQualityList.forEach(map -> {
            String basicInformation="单位："+map.get("unitDeptName")+"\n"+
                    "线别："+map.get("lineName")+"\n"+
                    "所亭："+map.get("bdsSubstationName")+"\n"+
                    "开关号："+map.get("switchNo")+"\n"+
                    "故障地点："+map.get("faultPlace")+"\n"+
                    "发生时间："+DateUtil.formatDateString(map.get("stopDate"), DateUtil.DATE_FORMAT)+"\n"+
                    "停时（分钟）："+map.get("stopMinute")+"\n"+
                    "天气："+map.get("weatherInfo")+"\n"+
                    "专业分类："+map.get("faultMajorName")+"\n";
            String segmentAnalysis="单位："+map.get("unitDeptName")+"\n"+
                    "单位：详见分析报告"+"\n";
            String isTrack="";
            if(bureauDayShiftVo.getTrackFlag()==0){
                isTrack="否";
            }else{
                isTrack="是";
            }
            String review="科室："+map.get("trackUnitDeptName")+"\n"+
                    "问题类别："+map.get("faultCategoryConfigName")+"\n"+
                    "定责考核："+map.get("dutyType")+"\n"+
                    "审核结果："+map.get("switchNo")+"\n"+
                    "重点追踪："+isTrack+"\n";
            BureauDayShiftExcelVo bureauDayShiftExcelVo =new BureauDayShiftExcelVo(
                    DateUtil.formatDateString(map.get("inputDate"), DateUtil.DATE_FORMAT),
                    basicInformation,
                    (String)map.get("faultDescription"),
                    (String)map.get("reportType"),
                    segmentAnalysis,
                    review,
                    map.get("safeQualityState").toString(),
                    String.valueOf(bureauDayShiftVo.getTrackFlag()));
            exportList.add(bureauDayShiftExcelVo);
        });

        ExportParams exportParams = new ExportParams();
        //设置边框样式
//        exportParams.setStyle(ExcelStyleType.BORDER.getClazz());
        // 设置sheet的名称
        if(bureauDayShiftVo.getTrackFlag()==0){
            exportParams.setSheetName("日安全质量信息");
        }else{
            exportParams.setSheetName("供电处重点追踪信息");
        }

        Map<String, Object> map = new HashMap<>();
        // title的参数为ExportParams类型，目前仅仅在ExportParams中设置了sheetName
        map.put("title", exportParams);
        // 模版导出对应得实体类型，即包含了List的对象
        map.put("entity", BureauDayShiftExcelVo.class);
        // sheet中要填充得数据
        map.put("data", exportList);
        return map;
    }


    /**
     * @Author Zhongks
     * @Description //TODO 返回天窗兑现统计excel信息
     * @Date 10:59 2021/5/8
     * @Param []
     * @return java.util.Map<java.lang.String,java.lang.Object>
     **/
    public Map<String, Object> getSkylightCashStatisticsMap(){
        List<BureauSkylightCashStatisticsExcelVo> exportList = new LinkedList<>();

        //ToDo 得到天窗兑现统计列表数据并进行封装
        //示例数据
        BureauSkylightCashStatisticsCommonExcelVo applicationExcelVo=new BureauSkylightCashStatisticsCommonExcelVo("申请供电类","申请非供电类");
        BureauSkylightCashStatisticsCommonExcelVo applicationTimeExcelVo=new BureauSkylightCashStatisticsCommonExcelVo("申请时间供电类","申请时间非供电类");
        BureauSkylightCashStatisticsCommonExcelVo getTimeExcelVo=new BureauSkylightCashStatisticsCommonExcelVo("给点时间供电类","给点时间非供电类");
        BureauSkylightCashStatisticsCommonExcelVo workTimeExcelVo=new BureauSkylightCashStatisticsCommonExcelVo(null,null);
        BureauSkylightCashStatisticsExcelVo bureauSkylightCashStatisticsExcelVo =new BureauSkylightCashStatisticsExcelVo("怀化供电段","高铁","沪昆高速线",
                applicationExcelVo,"取消","10","10",applicationTimeExcelVo,getTimeExcelVo,workTimeExcelVo,"天窗取消原因");
        exportList.add(bureauSkylightCashStatisticsExcelVo);
        exportList.add(bureauSkylightCashStatisticsExcelVo);
        exportList.add(bureauSkylightCashStatisticsExcelVo);

        //供电处重点追踪信息表
        ExportParams exportParams = new ExportParams();
        //设置边框样式
//        exportParams.setStyle(ExcelStyleType.BORDER.getClazz());
        // 设置sheet的名称
        exportParams.setSheetName("天窗兑现统计");

        Map<String, Object> map = new HashMap<>();
        // title的参数为ExportParams类型，目前仅仅在ExportParams中设置了sheetName
        map.put("title", exportParams);
        // 模版导出对应得实体类型，即包含了List的对象
        map.put("entity", BureauSkylightCashStatisticsExcelVo.class);
        // sheet中要填充得数据
        map.put("data", exportList);
        return map;
    }

    
    /**
     * @Author Zhongks
     * @Description //TODO 返回其他安全信息excel信息
     * @Date 11:01 2021/5/8
     * @Param []
     * @return java.util.Map<java.lang.String,java.lang.Object>
     **/
    public Map<String, Object> getOtherSafeQualityInfoMap(BureauDayShiftVo bureauDayShiftVo){
        List<BureauOtherSafeQualityInfoExcelVo> exportList = new LinkedList<>();
        //ToDo 得到其他安全信息列表数据并进行封装
        BureauSafeQualityOtherInfoVo bureauSafeQualityOtherInfoVo=new BureauSafeQualityOtherInfoVo();
        bureauSafeQualityOtherInfoVo.setStartDate(bureauDayShiftVo.getStartDate());
        bureauSafeQualityOtherInfoVo.setEndDate(bureauDayShiftVo.getEndDate());
        List<Map<String, Object>> list = bureauSafeQualityOtherInfoService.findList(bureauSafeQualityOtherInfoVo);
        list.forEach(map->{
            BureauOtherSafeQualityInfoExcelVo otherSafeQualityInfoExcelVo=new BureauOtherSafeQualityInfoExcelVo(
                    DateUtil.formatDateString(map.get("createDatetime"), DateUtil.DATE_FORMAT),
                    (String)map.get("description"),
                    (String)map.get("inputStaffName"),
                    DateUtil.formatDateString(map.get("createDatetime"), DateUtil.DATE_FORMAT),
                    (String)map.get("modifyStaffName"),
                    DateUtil.formatDateString(map.get("updateDatetime"), DateUtil.DATE_FORMAT)
            );
            exportList.add(otherSafeQualityInfoExcelVo);
        });

        //供电处重点追踪信息表
        ExportParams exportParams = new ExportParams();
        //设置边框样式
//        exportParams.setStyle(ExcelStyleType.BORDER.getClazz());
        // 设置sheet的名称
        exportParams.setSheetName("其他安全信息");

        Map<String, Object> map = new HashMap<>();
        // title的参数为ExportParams类型，目前仅仅在ExportParams中设置了sheetName
        map.put("title", exportParams);
        // 模版导出对应得实体类型，即包含了List的对象
        map.put("entity", BureauOtherSafeQualityInfoExcelVo.class);
        // sheet中要填充得数据
        map.put("data", exportList);
        return map;
    }


    /**
     * @Author Zhongks
     * @Description //TODO 返回安全质量考核excel信息
     * @Date 11:04 2021/5/8
     * @Param []
     * @return java.util.Map<java.lang.String,java.lang.Object>
     **/
    public Map<String, Object> getSafeQualityAssessmentMap(){
        List<BureauSafeQualityAssessmentExcelVo> exportList = new LinkedList<>();

        //ToDo 得到安全质量考核列表数据并进行封装


        //供电处重点追踪信息表
        ExportParams exportParams = new ExportParams();
        //设置边框样式
//        exportParams.setStyle(ExcelStyleType.BORDER.getClazz());
        // 设置sheet的名称
        exportParams.setSheetName("安全质量考核");

        Map<String, Object> map = new HashMap<>();
        // title的参数为ExportParams类型，目前仅仅在ExportParams中设置了sheetName
        map.put("title", exportParams);
        // 模版导出对应得实体类型，即包含了List的对象
        map.put("entity", BureauSafeQualityAssessmentExcelVo.class);
        // sheet中要填充得数据
        map.put("data", exportList);
        return map;
    }


    /**
     * @Author Zhongks
     * @Description //TODO 合并sheet
     * @Date 10:39 2021/5/11
     * @Param [targetWorkbook, sourceWorkbook]
     * @return org.apache.poi.ss.usermodel.Workbook
     **/
    public static Workbook mergeWorkSheet(Workbook targetWorkbook, Workbook sourceWorkbook){
        try{
            //第一个sheet
            Sheet firstSourceSheet=sourceWorkbook.getSheetAt(0);
            //获得第一个sheet总行数
            int firstSourceSheetLen=firstSourceSheet.getPhysicalNumberOfRows();
            //获取第几个工作表
            Sheet secondSourceSheet= sourceWorkbook.getSheetAt(1);
            int secondSourceSheetLen=secondSourceSheet.getPhysicalNumberOfRows();
            Sheet thirdSourceSheet=sourceWorkbook.getSheetAt(2);
            int thirdSourceSheetLen=thirdSourceSheet.getPhysicalNumberOfRows();
            Sheet fourSourceSheet=sourceWorkbook.getSheetAt(3);
            int fourSourceSheetLen=fourSourceSheet.getPhysicalNumberOfRows();
            Sheet fiveSourceSheet=sourceWorkbook.getSheetAt(4);
            //表合并后新表名称
            Sheet targetSheet = targetWorkbook.createSheet("安全质量信息日交班表");
            //表合并（根据startRow来控制各个表之间的距离，这里为空一行）
            POIUtil.copySheet(targetSheet, firstSourceSheet, targetWorkbook, sourceWorkbook,0,null);
            POIUtil.copySheet(targetSheet, secondSourceSheet, targetWorkbook, sourceWorkbook,firstSourceSheetLen+1,null);
            int thirdSourceSheetColLen=thirdSourceSheet.getRow(0).getPhysicalNumberOfCells();
            //得到需要合并单元格的坐标列表，row与col都从0开始计算
            List<CellRangeAddressExcelVo> cellRangeAddressExcelVoList = getCellRangeAddressExcelVoList(firstSourceSheetLen+secondSourceSheetLen+2, thirdSourceSheetColLen);
            //第三张表需要进行合并单元格操作
            POIUtil.copySheet(targetSheet, thirdSourceSheet, targetWorkbook, sourceWorkbook,firstSourceSheetLen+secondSourceSheetLen+2,cellRangeAddressExcelVoList);
            POIUtil.copySheet(targetSheet, fourSourceSheet, targetWorkbook, sourceWorkbook,firstSourceSheetLen+secondSourceSheetLen+thirdSourceSheetLen+3,null);
            POIUtil.copySheet(targetSheet, fiveSourceSheet, targetWorkbook, sourceWorkbook,firstSourceSheetLen+secondSourceSheetLen+thirdSourceSheetLen+fourSourceSheetLen+4,null);
            return targetWorkbook;
        }catch (Exception e){
            log.error("Workbook合并出错",e);
            return null;
        }
    }

    /**
     * @Author Zhongks
     * @Description //TODO 根据表格场景自定义需要返回合并的单元格位置坐标（注意：row与col都从0开始计算）
     * @Date 14:23 2021/5/11
     * @Param [row, col]
     * @return java.util.List<com.cdtye.itps.jjxt.model.excel.CellRangeAddressExcelVo>
     **/
    public static List<CellRangeAddressExcelVo> getCellRangeAddressExcelVoList(int row,int col){
        //合并单元格坐标位置
        List<CellRangeAddressExcelVo> list=new LinkedList<>();
        for(int i=0;i<15;i++){
            if(i<7){
                CellRangeAddressExcelVo cellRangeAddressExcelVo=new CellRangeAddressExcelVo(row,row+1,i,i);
                list.add(cellRangeAddressExcelVo);
            }else{
                CellRangeAddressExcelVo cellRangeAddressExcelVo=new CellRangeAddressExcelVo(row,row,i,i+1);
                list.add(cellRangeAddressExcelVo);
                i++;
            }
        }
        return list;
    }