POI对Excel自定义日期格式的读取

<p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Helvetica, Tahoma, Arial, sans-serif; font-size: 14px; line-height: 25.1875px;">用POI读取Excel数据：（版本号：POI3.7）</p><p style="margin-top: 0px; margin-bottom: 0px; padding-top: 0px; padding-bottom: 0px; font-family: Helvetica, Tahoma, Arial, sans-serif; font-size: 14px; line-height: 25.1875px;">1、读取Excel</p>

private List<String[]> rosolveFile(InputStream is, String suffix,int startRow) throws IOException, FileNotFoundException {Workbook xssfWorkbook = null;if ("xls".equals(suffix)) {xssfWorkbook = new HSSFWorkbook(is);} else if ("xlsx".equals(suffix)) {xssfWorkbook = new XSSFWorkbook(is);}Sheet xssfSheet = xssfWorkbook.getSheetAt(0);if (xssfSheet == null) {return null;}ArrayList<String[]> list = new ArrayList<String[]>();int lastRowNum = xssfSheet.getLastRowNum();for (int rowNum = startRow; rowNum <= lastRowNum; rowNum++) {if (xssfSheet.getRow(rowNum) != null) {Row xssfRow = xssfSheet.getRow(rowNum);short firstCellNum = xssfRow.getFirstCellNum();short lastCellNum = xssfRow.getLastCellNum();if (firstCellNum != lastCellNum) {String[] values = new String[lastCellNum];for (int cellNum = firstCellNum; cellNum < lastCellNum; cellNum++) {Cell xssfCell = xssfRow.getCell(cellNum);if (xssfCell == null) {values[cellNum] = "";} else {values[cellNum] = parseExcel(xssfCell);}}list.add(values);}}}return list;}

2、Excel数据处理：Excel存储日期、时间均以数值类型进行存储，读取时POI先判断是是否是数值类型，再进行判断转化1、数值格式(CELL_TYPE_NUMERIC):1.纯数值格式：getNumericCellValue() 直接获取数据2.日期格式：处理yyyy-MM-dd, d/m/yyyy h:mm, HH:mm 等不含文字的日期格式1).判断是否是日期格式：HSSFDateUtil.isCellDateFormatted(cell)2).判断是日期或者时间cell.getCellStyle().getDataFormat() == HSSFDataFormat.getBuiltinFormat("h:mm")OR:cell.getCellStyle().getDataFormat() == HSSFDataFormat.getBuiltinFormat("yyyy-MM-dd")3.自定义日期格式：处理yyyy年m月d日,h时mm分,yyyy年m月等含文字的日期格式判断cell.getCellStyle().getDataFormat()值，解析数值格式yyyy年m月d日----->31m月d日---->58h时mm分--->322、字符格式(CELL_TYPE_STRING):直接获取内容 

private String parseExcel(Cell cell) {String result = new String();switch (cell.getCellType()) {case HSSFCell.CELL_TYPE_NUMERIC:// 数字类型if (HSSFDateUtil.isCellDateFormatted(cell)) {// 处理日期格式、时间格式SimpleDateFormat sdf = null;if (cell.getCellStyle().getDataFormat() == HSSFDataFormat.getBuiltinFormat("h:mm")) {sdf = new SimpleDateFormat("HH:mm");} else {// 日期sdf = new SimpleDateFormat("yyyy-MM-dd");}Date date = cell.getDateCellValue();result = sdf.format(date);} else if (cell.getCellStyle().getDataFormat() == 58) {// 处理自定义日期格式：m月d日(通过判断单元格的格式id解决，id的值是58)SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");double value = cell.getNumericCellValue();Date date = org.apache.poi.ss.usermodel.DateUtil.getJavaDate(value);result = sdf.format(date);} else {double value = cell.getNumericCellValue();CellStyle style = cell.getCellStyle();DecimalFormat format = new DecimalFormat();String temp = style.getDataFormatString();// 单元格设置成常规if (temp.equals("General")) {format.applyPattern("#");}result = format.format(value);}break;case HSSFCell.CELL_TYPE_STRING:// String类型result = cell.getRichStringCellValue().toString();break;case HSSFCell.CELL_TYPE_BLANK:result = "";default:result = "";break;}return result;}

 *万能处理方案：所有日期格式都可以通过getDataFormat()值来判断yyyy-MM-dd-----14yyyy年m月d日---31yyyy年m月-------57m月d日  ----------58HH:mm-----------20h时mm分  -------32

	//1、判断是否是数值格式if(cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC){short format = cell.getCellStyle().getDataFormat();SimpleDateFormat sdf = null;if(format == 14 || format == 31 || format == 57 || format == 58){//日期sdf = new SimpleDateFormat("yyyy-MM-dd");}else if (format == 20 || format == 32) {//时间sdf = new SimpleDateFormat("HH:mm");}double value = cell.getNumericCellValue();Date date = org.apache.poi.ss.usermodel.DateUtil.getJavaDate(value);result = sdf.format(date);}