代码：

package com.ly.cloud.util;import cn.hutool.core.collection.CollUtil;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.merge.AbstractMergeStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicInteger;/*** @Author * @Date Created in  2023/12/12 12:44* @DESCRIPTION: 合并单元格工具类* @Version V1.0*/public class CustomMergeStrategyUtil extends AbstractMergeStrategy {/*** 分组，每几行合并一次*/public List<List<Integer>> mergeColDataGroupCountList;/*** 目标合并列index*/public List<Integer> targetColumnIndex;/*** 	需要开始合并单元格的首行index*/public Integer rowIndex;/*** 	mergeColDataList为待合并目标列的值*/public CustomMergeStrategyUtil(List<List<String>> mergeColDataList, List<Integer> targetColumnIndex) {this.mergeColDataGroupCountList = getGroupCountList(mergeColDataList);this.targetColumnIndex = targetColumnIndex;}@Overridepublic void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {if (null == rowIndex) {rowIndex = cell.getRowIndex();}// 仅从首行以及目标列的单元格开始合并，忽略其他if (cell.getRowIndex() == rowIndex && targetColumnIndex.contains(cell.getColumnIndex())) {//找到对应的需要合并的列AtomicInteger i = new AtomicInteger(0);Optional<Integer> first = targetColumnIndex.stream().filter(col -> {i.getAndIncrement();return col == cell.getColumnIndex();}).findFirst();mergeGroupColumn(sheet, first.get());}}public void mergeGroupColumn(Sheet sheet, Integer index) {int rowCount = rowIndex;for (Integer count : mergeColDataGroupCountList.get(index)) {if (count == 1) {rowCount += count;continue;}// 合并单元格CellRangeAddress cellRangeAddress = new CellRangeAddress(rowCount, rowCount + count - 1,targetColumnIndex.get(index), targetColumnIndex.get(index));sheet.addMergedRegionUnsafe(cellRangeAddress);rowCount += count;}}/*** 	该方法将目标列根据值是否相同连续可合并，存储可合并的行数*/public List<List<Integer>> getGroupCountList(List<List<String>> exportDataList) {if (CollUtil.isEmpty(exportDataList)) {return new ArrayList<>();}List<List<Integer>> groupCountListList = new ArrayList<>();exportDataList.forEach(dataList->{List<Integer> groupCountList = new ArrayList<>();int count = 1;for (int i = 1; i < dataList.size(); i++) {if (dataList.get(i).equals(dataList.get(i - 1))) {count++;} else {groupCountList.add(count);count = 1;}}// 处理完最后一条后groupCountList.add(count);groupCountListList.add(groupCountList);});return groupCountListList;}
}

使用：

        List<List<String>> mergeColDataList = Stream.of(pzry.stream().map(PzrtExportDto::getXh).collect(Collectors.toList()),pzry.stream().map(PzrtExportDto::getDwmc).collect(Collectors.toList())).collect(Collectors.toList());//第一列(index=0)和第二列(index=1)List<Integer> mergeColIndexList = Stream.of(0, 1).collect(Collectors.toList());//内部finish的时候会自动关闭流EasyExcel.write(response.getOutputStream(), PzrtExportDto.class)// 这个方法====-——---》                    .registerWriteHandler(new CustomMergeStrategyUtil(mergeColDataList, mergeColIndexList))  合并单元格.inMemory(Boolean.TRUE).registerWriteHandler(new CommentWriteHandler()).sheet(FILE_NAME).doWrite(pzry);