EasyExcel填充时合并单元格

由于填充时第二行开始，easyexcel不会自动合并单元格，所以需要自定义handler根据上一行的合并信息自行合并

public class MyHandler extends AbstractMergeStrategy {
    

    @Override
    protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
        if(relativeRowIndex==null ||relativeRowIndex==0){           
            return;
        }       
        int rowIndex = cell.getRowIndex(); 
        int colIndex = cell.getColumnIndex();
        sheet=cell.getSheet();
        Row preRow = sheet.getRow(rowIndex - 1);
        Cell preCell = preRow.getCell(colIndex);//获取上一行的该格
        List list = sheet.getMergedRegions();
        CellStyle cs = cell.getCellStyle();
        cell.setCellStyle(cs);
        for (int i = 0; i < list.size(); i++) {
            CellRangeAddress cellRangeAddress = list.get(i);
            if (cellRangeAddress.containsRow(preCell.getRowIndex()) && cellRangeAddress.containsColumn(preCell.getColumnIndex())) {
                int lastColIndex = cellRangeAddress.getLastColumn();
                int firstColIndex = cellRangeAddress.getFirstColumn();
                CellRangeAddress cra = new CellRangeAddress(cell.getRowIndex(), cell.getRowIndex(), firstColIndex, lastColIndex);
                sheet.addMergedRegion(cra);
                RegionUtil.setBorderBottom(BorderStyle.THIN, cra, sheet); 
                RegionUtil.setBorderLeft(BorderStyle.THIN, cra, sheet);  
                RegionUtil.setBorderRight(BorderStyle.THIN, cra, sheet); 
                RegionUtil.setBorderTop(BorderStyle.THIN, cra, sheet);
                return;
            }
        }

    }

}

调用

ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream()).withTemplate(Objects.requireNonNull(DeviceController.class.getClassLoader().getResourceAsStream("/excel/devmsg.xlsx"))).build();
        WriteSheet writeSheet = EasyExcel.writerSheet().build();
        WriteSheet writeSheet1 = EasyExcel.writerSheet().registerWriteHandler(new MyHandler()).build();
        FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();      
        excelWriter.fill(bm, writeSheet1);//写入设备基础信息
        excelWriter.fill(new FillWrapper("data1", list), fillConfig, writeSheet1);
        excelWriter.fill(new FillWrapper("data2", list1), fillConfig, writeSheet1);
        excelWriter.fill(new FillWrapper("data3", list2), fillConfig, writeSheet1);
        excelWriter.fill(new FillWrapper("data4", list3), fillConfig, writeSheet1);
        
        excelWriter.finish();