easyExcel或poi导出excel合并单元格的问题(java)_easyexcel导出合并单元格失效-优快云博客

原文链接:EasyExcel导出多列相同合并处理以及单列相同合并处理_easyexcel怎么实现多个列分别合并-优快云博客
我对自定义多列相同合并策略处理类进行了一些修改，原文进行多行合并的时候会导致报错（上一行已合并的问题），所以处理了一下重新添加合并单元的逻辑,代码如下:

import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import java.util.List;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;

/**
 * @ClassName:ExcelMergeCustomerCellHandler @Description:easyexcel合并策略处理类，多列相同合并策略 @Version:1.0 @Date:2023/9/7
 * 09:36:52
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
public class ExcelCellByMultiHandler implements CellWriteHandler {

  /** 用第几行开始合并 ，默认为1，因为第0行是标题，EasyExcel 的默认也是 */
  private int mergeRowIndex = 1;

  /** 参与合并的列，起始列位置，默认为0 */
  private int mergeColumnStart = 0;

  /** 参与合并的列，最后一列的位置，默认为4 */
  private int mergeColumnEnd = 4;

  /*
   * 在对单元格的所有操作完成后调用
   */
  @Override
  public void afterCellDispose(
      WriteSheetHolder writeSheetHolder,
      WriteTableHolder writeTableHolder,
      List<WriteCellData<?>> list,
      Cell cell,
      Head head,
      Integer integer,
      Boolean aBoolean) {
    // 当前行
    int curRowIndex = cell.getRowIndex();
    // 当前列
    int curColIndex = cell.getColumnIndex();
    if (curRowIndex > mergeRowIndex && curColIndex >= mergeColumnStart) {
      // 读取到mergeColumnEnd ，开始调用合并方法
      if (curColIndex == mergeColumnEnd) {
        mergeWithPrevRow(writeSheetHolder, cell, curRowIndex);
      }
    }
  }

  /**
   * @Description: 合并比较多列值是否相同 @Date: 2023/9/8 16:31 @Param writeSheetHolder: 通过此对象获取sheet等信息 @Param
   * cell: 当前单元格 @Param curRowIndex: 当前行
   *
   * @return: void
   */
  private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, Cell cell, int curRowIndex) {
    StringBuilder curString = new StringBuilder();
    StringBuilder preString = new StringBuilder();
    for (int i = mergeColumnStart; i <= mergeColumnEnd; i++) {
      Cell curCell = cell.getSheet().getRow(curRowIndex).getCell(i);
      Cell preCell = cell.getSheet().getRow(curRowIndex - 1).getCell(i);
      // 根据单元格类型获取单元格的值
      Object curData =
          curCell.getCellType() == CellType.STRING
              ? curCell.getStringCellValue()
              : curCell.getNumericCellValue();
      Object preData =
          preCell.getCellType() == CellType.STRING
              ? preCell.getStringCellValue()
              : preCell.getNumericCellValue();
      curString.append(curData);
      preString.append(preData);
    }
    // 比较当前行的单元格与上一行是否相同，相同合并当前单元格与上一行
    if (curString.toString().equals(preString.toString())) {
      Sheet sheet = writeSheetHolder.getSheet();
      // 获取合并信息
      boolean isMerged = false;
      // 下标
      for (int j = 0; j <= mergeColumnEnd; j++) {
        List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
        for (int i = 0; i < mergeRegions.size(); i++) {
          CellRangeAddress cellRangeAddr = mergeRegions.get(i);
          // 若上一个单元格已经被合并，则先移出原有的合并单元，再重新添加合并单元
          if (cellRangeAddr.isInRange(curRowIndex - 1, j)) {
            sheet.removeMergedRegion(i);
            cellRangeAddr.setLastRow(curRowIndex);
            sheet.addMergedRegion(cellRangeAddr);
            isMerged = true;
            break;
          }
        }
      }
      if (!isMerged) {
        for (int i = 0; i <= mergeColumnEnd; i++) {
          CellRangeAddress cellRangeAddress =
              new CellRangeAddress(curRowIndex - 1, curRowIndex, i, i);
          sheet.addMergedRegion(cellRangeAddress);
        }
      }
    }
  }
}

上面的三个参数根据实际导出情况自行调整