表格根據字數自適應

/**
     * 把ComparisonData對象轉換爲Excel文件
     *@author luoyi
     * @param list
     * @param filename
     * @param ComparisonDatarows
     * @param session
     */
    public void createExcel(List<ComparisonData> list, String filename, String photoFileName, String[] ComparisonDatarows, HttpSession session) {
        HSSFWorkbook wkb = new HSSFWorkbook();
        //創建一個樣式
        HSSFCellStyle cellStyle = wkb.createCellStyle();
        cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
        cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//垂直居中
        // 設置邊框
        cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
        cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
        cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
        cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
        // 自動換行
//        cellStyle.setWrapText(true);
        //創建字體
        HSSFFont font = wkb.createFont();
        font.setFontHeightInPoints((short) 10);
        font.setColor(HSSFColor.BLACK.index);
        font.setFontName("宋體");
        // 把字體 應用到當前樣式
        cellStyle.setFont(font);
        //格式化單元格日期信息
        HSSFDataFormat dataFormat = wkb.createDataFormat();
        short dataformat = dataFormat.getFormat("yyyy-mm-dd");
        cellStyle.setDataFormat(dataformat);
        //建立新的sheet對象（excel的表單）
        HSSFSheet sheet = wkb.createSheet("人員表");
        //在sheet裏創建第一行，參數爲行索引(excel的行)，可以是0～65535之間的任何一個
        HSSFRow row1 = sheet.createRow(0);


        for (int i = 0; i < ComparisonDatarows.length; i++) {
            HSSFCell ce = row1.createCell(i);
            ce.setCellStyle(cellStyle);
            ce.setCellValue(ComparisonDataConvention.getComparisonDataRowName(ComparisonDatarows[i]));
        }
        List<String> oldFiles = new ArrayList<>();
        for (int i = 0; i < list.size(); i++) {
            HSSFRow row = sheet.createRow(i + 1);
            for (int j = 0; j < ComparisonDatarows.length; j++) {
                HSSFCell cell = row.createCell(j);

                cell.setCellStyle(cellStyle);
                String comparisonDataRow = getComparisonDataRow(ComparisonDatarows[j], list.get(i));
                cell.setCellValue(comparisonDataRow);
            }
            if (i % 100 == 0) {
                try {
                    Thread.sleep(200);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            for (String comparisonDatarow : ComparisonDatarows) {
                if ("authphoto".equals(comparisonDatarow)) {
                    String authphoto = list.get(i).getAuthphoto();
                    if (StringUtils.isNotBlank(authphoto)) {
                        oldFiles.add(authphoto);
                    }
                }
                if ("personphoto".equals(comparisonDatarow)) {
                    String personphoto = list.get(i).getPersonphoto();
                    if (StringUtils.isNotBlank(personphoto)) {
                        oldFiles.add(personphoto);
                    }
                }
                if ("photo".equals(comparisonDatarow)) {
                    String photo = list.get(i).getPhoto();
                    if (StringUtils.isNotBlank(photo)) {
                        oldFiles.add(photo);
                    }
                }
            }
        }
        //調整列的寬度
        for (int i = 0; i < ComparisonDatarows.length; i++) {
            sheet.autoSizeColumn(i);
        }
        setSizeColumn(sheet,ComparisonDatarows.length);

        String path = session.getServletContext().getRealPath("/") + Convention.EXCEL_EXPLODE_PATH+ File.separator+photoFileName;
        File pathFile = new File(path);
        if (!pathFile.exists()) {
            pathFile.mkdirs();
        }
        FileUtils.copyFolder(oldFiles,path,photoFileName);
        File file = new File(path + File.separator + filename);

        try {
            if (!file.exists()) {
                file.createNewFile();
            }
            OutputStream out = new FileOutputStream(file);
            wkb.write(out);
            out.flush();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

我們使用autoSizeColumn方法可以把Excel設置爲根據內容自動調整列寬，然而這個方法對中文並不起效，只對數字和字母有效；

    private void setSizeColumn(HSSFSheet sheet, int size) {
        for (int columnNum = 0; columnNum < size; columnNum++) {
            int columnWidth = sheet.getColumnWidth(columnNum) / 256;
            for (int rowNum = 0; rowNum < sheet.getLastRowNum(); rowNum++) {
                HSSFRow currentRow;
                //當前行未被使用過
                if (sheet.getRow(rowNum) == null) {
                    currentRow = sheet.createRow(rowNum);
                } else {
                    currentRow = sheet.getRow(rowNum);
                }

                if (currentRow.getCell(columnNum) != null) {
                    HSSFCell currentCell = currentRow.getCell(columnNum);
                    if (currentCell.getCellType() == HSSFCell.CELL_TYPE_STRING) {
                        int length = currentCell.getStringCellValue().getBytes().length+5;
                        if (columnWidth < length) {
                            columnWidth = length;
                        }
                    }
                }
            }
            sheet.setColumnWidth(columnNum, columnWidth * 256);
        }
    }

 https://blog.csdn.net/Pro_Mophy/article/details/81626119