如何使用

// 0,1 表示 对1,2列启用合并策略

EasyExcel.write(fileName, Model.class)

.registerWriteHandler(new MergeStrategy(data().size(),0,1))

.sheet("通用合并行策略")

.doWrite(data());

代码实现

import com.alibaba.excel.metadata.Head;import com.alibaba.excel.write.merge.AbstractMergeStrategy;import mons.collections.map.HashedMap;import org.apache.poi.ss.usermodel.Cell;import org.apache.poi.ss.usermodel.Sheet;import org.apache.poi.ss.util.CellRangeAddress;import java.util.*;public class MergeStrategy extends AbstractMergeStrategy {// 合并的列编号，从0开始，指定的index或自己按字段顺序数private Set<Integer> mergeCellIndex = new HashSet<>();// 数据集大小，用于区别结束行位置private Integer maxRow = 0;// 禁止无参声明private MergeStrategy() {}public MergeStrategy(Integer maxRow, int... mergeCellIndex) {Arrays.stream(mergeCellIndex).forEach(item -> {this.mergeCellIndex.add(item);});this.maxRow = maxRow;}// 记录上一次合并的信息private Map<Integer, MergeRange> lastRow = new HashedMap();// 每行每列都会进入，绝对不要在这写循环@Overrideprotected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {int currentCellIndex = cell.getColumnIndex();// 判断该行是否需要合并if (mergeCellIndex.contains(currentCellIndex)) {String currentCellValue = cell.getStringCellValue();int currentRowIndex = cell.getRowIndex();if (!lastRow.containsKey(currentCellIndex)) {// 记录首行起始位置lastRow.put(currentCellIndex, new MergeRange(currentCellValue, currentRowIndex, currentRowIndex, currentCellIndex, currentCellIndex));return;}//有上行这列的值了，拿来对比.MergeRange mergeRange = lastRow.get(currentCellIndex);if (!(mergeRange.lastValue != null && mergeRange.lastValue.equals(currentCellValue))) {// 结束的位置触发下合并.// 同行同列不能合并，会抛异常if (mergeRange.startRow != mergeRange.endRow || mergeRange.startCell != mergeRange.endCell) {sheet.addMergedRegionUnsafe(new CellRangeAddress(mergeRange.startRow, mergeRange.endRow, mergeRange.startCell, mergeRange.endCell));}// 更新当前列起始位置lastRow.put(currentCellIndex, new MergeRange(currentCellValue, currentRowIndex, currentRowIndex, currentCellIndex, currentCellIndex));}// 合并行 + 1mergeRange.endRow += 1;// 结束的位置触发下最后一次没完成的合并if (relativeRowIndex.equals(maxRow - 1)) {MergeRange lastMergeRange = lastRow.get(currentCellIndex);// 同行同列不能合并，会抛异常if (lastMergeRange.startRow != lastMergeRange.endRow || lastMergeRange.startCell != lastMergeRange.endCell) {sheet.addMergedRegionUnsafe(new CellRangeAddress(lastMergeRange.startRow, lastMergeRange.endRow, lastMergeRange.startCell, lastMergeRange.endCell));}}}}}class MergeRange {public int startRow;public int endRow;public int startCell;public int endCell;public String lastValue;public MergeRange(String lastValue, int startRow, int endRow, int startCell, int endCell) {this.startRow = startRow;this.endRow = endRow;this.startCell = startCell;this.endCell = endCell;this.lastValue = lastValue;}}