easyexcel 版本：3.0.5
    自定义单元格合并WriterHandler

    1. import com.alibaba.excel.metadata.Head;
    2. import com.alibaba.excel.write.handler.CellWriteHandler;
    3. import com.alibaba.excel.write.merge.AbstractMergeStrategy;
    4. import org.apache.commons.collections4.CollectionUtils;
    5. import org.apache.poi.ss.usermodel.Cell;
    6. import org.apache.poi.ss.usermodel.CellType;
    7. import org.apache.poi.ss.usermodel.Row;
    8. import org.apache.poi.ss.usermodel.Sheet;
    9. import org.apache.poi.ss.util.CellRangeAddress;
    11. import java.util.HashSet;
    12. import java.util.List;
    13. import java.util.Objects;
    14. import java.util.Set;
    16. /**
    17. * @author mori
    18. * @date 2022/3/9
    19. */
    20. public class CellMergeWriterHandler {
    22.     public static CellWriteHandler getCellMergeWriterHandler(CellMergeEnum cellMergeEnum) {
    23.         if (CellMergeEnum.ROW.equals(cellMergeEnum)) {
    24.             return new RowMergeWriterHandler();
    25.         }
    26.         if (CellMergeEnum.COLUMN.equals(cellMergeEnum)) {
    27.             return new ColumnMergeWriterHandler();
    28.         }
    29.         return null;
    30.     }
    32.     public static CellWriteHandler getRowMergeWriterHandler(List<Integer> rows) {
    33.         return getCellWriteHandler(CellMergeEnum.ROW, rows);
    34.     }
    36.     public static CellWriteHandler getColumnMergeWriterHandler(List<Integer> cols) {
    37.         return getCellWriteHandler(CellMergeEnum.COLUMN, cols);
    38.     }
    40.     public static CellWriteHandler getCellWriteHandler(CellMergeEnum cellMergeEnum, List<Integer> columnsOrRows) {
    41.         if (CellMergeEnum.ROW.equals(cellMergeEnum)) {
    42.             return new RowMergeWriterHandler(new HashSet<>(columnsOrRows));
    43.         }
    44.         if (CellMergeEnum.COLUMN.equals(cellMergeEnum)) {
    45.             return new ColumnMergeWriterHandler(new HashSet<>(columnsOrRows));
    46.         }
    47.         return null;
    48.     }
    50.     public static class ColumnMergeWriterHandler extends AbstractMergeStrategy {
    52.         private Set<Integer> mergeCols;
    54.         public ColumnMergeWriterHandler() {
    55.         }
    57.         public ColumnMergeWriterHandler(Set<Integer> mergeCols) {
    58.             this.mergeCols = mergeCols;
    59.         }
    61.         @Override
    62.         protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
    63.             if (CollectionUtils.isNotEmpty(this.mergeCols) && !this.mergeCols.contains(cell.getColumnIndex())) {
    64.                 return;
    65.             }
    66.             mergeCell(cell.getSheet(), cell, CellMergeEnum.COLUMN);
    67.         }
    68.     }
    70.     public static class RowMergeWriterHandler extends AbstractMergeStrategy {
    72.         private Set<Integer> mergeCols;
    74.         public RowMergeWriterHandler() {
    75.         }
    77.         public RowMergeWriterHandler(Set<Integer> mergeCols) {
    78.             this.mergeCols = mergeCols;
    79.         }
    81.         @Override
    82.         protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
    83.             if (CollectionUtils.isNotEmpty(mergeCols) && !mergeCols.contains(cell.getColumnIndex())) {
    84.                 return;
    85.             }
    86.             mergeCell(cell.getSheet(), cell, CellMergeEnum.ROW);
    87.         }
    88.     }
    91.     private static void mergeCell(Sheet sheet, Cell cell, CellMergeEnum cellMergeEnum) {
    92.         if (Objects.isNull(cell)) {
    93.             return;
    94.         }
    95.         int rowIndex = cell.getRowIndex(), colIndex = cell.getColumnIndex();
    96.         Row preRow = null;
    97.         Cell preCell = null;
    98.         if (CellMergeEnum.ROW.equals(cellMergeEnum)) {
    99.             if (rowIndex == 0) {
    100.                 return;
    101.             }
    102.             preRow = sheet.getRow(rowIndex - 1);
    103.             if (Objects.isNull(preRow)) {
    104.                 return;
    105.             }
    106.             preCell = preRow.getCell(colIndex);
    107.         }
    108.         if (CellMergeEnum.COLUMN.equals(cellMergeEnum)) {
    109.             if (colIndex == 0) {
    110.                 return;
    111.             }
    112.             preRow = cell.getRow();
    113.             preCell = preRow.getCell(colIndex - 1);
    114.         }
    115.         if (Objects.isNull(preCell)) {
    116.             return;
    117.         }
    118.         Object preCellValue = getCellValue(preCell), curCellValue = getCellValue(cell);
    119.         if (Objects.isNull(preCellValue) || Objects.isNull(curCellValue) || !preCellValue.equals(curCellValue)) {
    120.             return;
    121.         }
    122.         merge(sheet, preCell, cell);
    123.     }
    125.     private static void merge(Sheet sheet, Cell preCell, Cell curCell) {
    126.         List<CellRangeAddress> list = sheet.getMergedRegions();
    127.         if (CollectionUtils.isEmpty(list)) {
    128.             sheet.addMergedRegionUnsafe(new CellRangeAddress(preCell.getRowIndex(), curCell.getRowIndex(), preCell.getColumnIndex(), curCell.getColumnIndex()));
    129.             return;
    130.         }
    131.         for (int i = 0; i < list.size(); i++) {
    132.             CellRangeAddress cellRangeAddress = list.get(i);
    133.             if (cellRangeAddress.containsRow(preCell.getRowIndex()) && cellRangeAddress.containsColumn(preCell.getColumnIndex())) {
    134.                 int firstRowIndex = cellRangeAddress.getFirstRow(), firstColIndex = cellRangeAddress.getFirstColumn();
    135.                 sheet.removeMergedRegion(i);
    136.                 sheet.addMergedRegionUnsafe(new CellRangeAddress(firstRowIndex, curCell.getRowIndex(), firstColIndex, curCell.getColumnIndex()));
    137.                 return;
    138.             }
    139.         }
    140.         sheet.addMergedRegionUnsafe(new CellRangeAddress(preCell.getRowIndex(), curCell.getRowIndex(), preCell.getColumnIndex(), curCell.getColumnIndex()));
    141.     }
    143.     protected static Object getCellValue(Cell cell) {
    144.         if (Objects.isNull(cell)) {
    145.             return null;
    146.         }
    147.         CellType cellTypeEnum = cell.getCellType();
    148.         switch (cellTypeEnum) {
    149.             case STRING:
    150.                 return cell.getStringCellValue();
    151.             case BOOLEAN:
    152.                 return cell.getBooleanCellValue();
    153.             case NUMERIC:
    154.                 return cell.getNumericCellValue();
    155.             default:
    156.                 return null;
    157.         }
    158.     }
    160.     public enum CellMergeEnum {
    161.         /**
    162.         * row
    163.         */
    164.         ROW,
    166.         /**
    167.         * column
    168.         */
    169.         COLUMN;
    170.     }
    171. }

    测试代码：

    1.     @Test
    2.     public void testTemplate() {
    3.         String templateFileName = "./src/test/resources/test_simple_list.xlsx";
    4.         String fileName = "./reports/listFill" + System.currentTimeMillis() + ".xlsx";
    5.         ByteArrayOutputStream out = new ByteArrayOutputStream();
    6.         ExcelWriter excelWriter = EasyExcel.write(out).withTemplate(templateFileName)
    7.                 .registerWriteHandler(CellMergeWriterHandler.getRowMergeWriterHandler(Arrays.asList(0, 1)))
    8.                 .autoCloseStream(Boolean.FALSE)
    9.                 .build();
    10.         WriteSheet writeSheet = EasyExcel.writerSheet(0).build();
    11.         // 直接写入数据
    12.         FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();
    13.         excelWriter.fill(dataMap(), fillConfig, writeSheet);
    14.         excelWriter.finish();
    15.         File file = new File(fileName);
    16.         try (FileOutputStream fileOutputStream = new FileOutputStream(file)) {
    17.             fileOutputStream.write(out.toByteArray());
    18.             fileOutputStream.flush();
    19.         } catch (Exception e) {
    20.             e.printStackTrace();
    21.         }
    22.     }
    25.     private List<Map<String, Object>> dataMap() {
    26.         List<Map<String, Object>> list = ListUtils.newArrayList();
    27.         for (int i = 0; i < 5; i++) {
    28.             Map<String, Object> object = new HashMap<>();
    29.             list.add(object);
    30.             if (i % 3 == 0) {
    31.                 object.put("name", "张三3");
    32.                 object.put("number", null);
    33.             } else {
    34.                 object.put("number", 5.2);
    35.                 object.put("name", "张三");
    36.             }
    37.         }
    38.         return list;
    39.     }

    模板：
    image.png
    运行效果：
    image.png
    A列和B列相同数值行合并。