poi读取excel日期格式 POI对Excel自定义日期格式的读取(实例代码)

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; 
  } 

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; 
  } 

//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); 
}