java excel合并内容相同的单元格

您好！对于您的问题，可以通过使用POI库来实现Java Excel合并内容相同的单元格。具体实现可以参考以下代码：

import org.apache.poi.ss.usermodel.*;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class ExcelCellMerger {
    public static void main(String[] args) throws IOException {
        // 读取Excel文件
        File file = new File("test.xlsx");
        FileInputStream inputStream = new FileInputStream(file);
        Workbook workbook = WorkbookFactory.create(inputStream);

        // 遍历所有Sheet
        for (int sheetIndex = 0; sheetIndex < workbook.getNumberOfSheets(); sheetIndex++) {
            Sheet sheet = workbook.getSheetAt(sheetIndex);

            // 遍历所有行
            Map<String, CellRangeAddress> mergedCellMap = new HashMap<>();
            for (int rowIndex = 0; rowIndex <= sheet.getLastRowNum(); rowIndex++) {
                Row row = sheet.getRow(rowIndex);
                if (row == null) {
                    continue;
                }

                // 遍历所有列
                for (int columnIndex = 0; columnIndex <= row.getLastCellNum(); columnIndex++) {
                    Cell cell = row.getCell(columnIndex);
                    if (cell == null) {
                        continue;
                    }

                    // 获取当前单元格的值
                    String cellValue = cell.getStringCellValue();

                    // 判断当前单元格是否需要合并
                    if (mergedCellMap.containsKey(cellValue)) {
                        CellRangeAddress mergedCell = mergedCellMap.get(cellValue);
                        int firstRow = mergedCell.getFirstRow();
                        int lastRow = mergedCell.getLastRow();
                        int firstColumn = mergedCell.getFirstColumn();
                        int lastColumn = mergedCell.getLastColumn();

                        if (rowIndex > lastRow && columnIndex == firstColumn) {
                            // 需要合并的单元格在下一行
                            mergedCell.setLastRow(rowIndex);
                            sheet.addMergedRegion(mergedCell);
                            mergedCellMap.put(cellValue, mergedCell);
                        }
                    } else {
                        // 新的单元格需要合并
                        CellRangeAddress newMergedCell = new CellRangeAddress(rowIndex, rowIndex, columnIndex, columnIndex);
                        sheet.addMergedRegion(newMergedCell);
                        mergedCellMap.put(cellValue, newMergedCell);
                    }
                }
            }
        }

        // 保存Excel文件
        FileOutputStream outputStream = new FileOutputStream(file);
        workbook.write(outputStream);
        outputStream.close();
    }
}

希望能够解决您的问题！