poi读取Excel

/**
	 * 读出excel内容
	 * 
	 * @param is
	 * @return
	 * @throws IOException
	 */
	@SuppressWarnings("unchecked")
	private List<String[]> getExcelData(InputStream is) throws IOException {
		List<String[]> data = new ArrayList<String[]>();
		HSSFWorkbook wb = new HSSFWorkbook(is);
		SimpleDateFormat sf1 = new SimpleDateFormat("yyyy-MM-dd");
		SimpleDateFormat sf2 = new SimpleDateFormat("HH:mm");

		for (int i = 0; i < wb.getNumberOfSheets(); i++) {
			HSSFSheet sheet = wb.getSheetAt(i);
			Iterator<HSSFRow> rit = (Iterator<HSSFRow>) sheet.rowIterator();
			while (rit.hasNext()) {
				HSSFRow row = rit.next();
				if (row.getRowNum() == 0) {
					continue;
				}
				String[] strArray = new String[row.getLastCellNum()];
				int count = 0;
				for (short j = 0; j < row.getLastCellNum(); j++) {
					HSSFCell cell = row.getCell(j);
					if (cell == null) {
						strArray[count++] = "";
						continue;
					}
					String cellValue = "";
					switch (cell.getCellType()) {
					case HSSFCell.CELL_TYPE_NUMERIC:
						if (HSSFDateUtil.isCellDateFormatted(cell)) {

							Date date = cell.getDateCellValue();
							GregorianCalendar cal = new GregorianCalendar();
							cal.setTime(date);
							cellValue = cal.get(Calendar.YEAR) < 1950 ? sf2
									.format(date) : sf1.format(date);
						} else {
							cellValue = cell.getNumericCellValue() + "";
							try {
								cellValue = cellValue.substring(0, cellValue
										.indexOf("."));
							} catch (Exception ignore) {
							}
						}
						break;
					case HSSFCell.CELL_TYPE_STRING:
						cellValue = cell.getRichStringCellValue().toString();
						break;
					case HSSFCell.CELL_TYPE_FORMULA:
						cellValue = cell.getNumericCellValue() + "";
						break;
					default:
						cellValue = "";
						break;
					}
					strArray[count++] = cellValue;
				}
				data.add(strArray);
			}
		}
		return data;
	}