<dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.10-FINAL</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.10-FINAL</version>
        </dependency>
 

  /**
     * 讀入excel檔案，解析後返回
     * @param file
     * @throws IOException
     */
    public static List<String[]> readExcel(MultipartFile file) throws IOException{
        //檢查檔案
        checkFile(file);
        //獲得Workbook工作薄物件
        Workbook workbook = getWorkBook(file);
        //建立返回物件，把每行中的值作為一個數組，所有行作為一個集合返回
        List<String[]> list = new ArrayList<String[]>();

        if(workbook != null){
            for(int sheetNum = 0;sheetNum < workbook.getNumberOfSheets();sheetNum++){
                //獲得當前sheet工作表
                Sheet sheet = workbook.getSheetAt(sheetNum);
                if(sheet == null){
                    continue;
                }
                //獲得當前sheet的開始行
                int firstRowNum  = sheet.getFirstRowNum();
                //獲得當前sheet的結束行
                int lastRowNum = sheet.getLastRowNum();
                //迴圈除了第一行的所有行
                for(int rowNum = firstRowNum+1;rowNum <= lastRowNum;rowNum++){ //為了過濾到第一行因為我的第一行是資料庫的列
                    //獲得當前行
                    Row row = sheet.getRow(rowNum);
                    if(row == null){
                        continue;
                    }
                    //獲得當前行的開始列
                    int firstCellNum = row.getFirstCellNum();
                    //獲得當前行的列數
                    int lastCellNum = row.getLastCellNum();//為空列獲取
//                    int lastCellNum = row.getPhysicalNumberOfCells();//為空列不獲取
//                    String[] cells = new String[row.getPhysicalNumberOfCells()];
                    String[] cells = new String[row.getLastCellNum()];
                    //迴圈當前行
                    for(int cellNum = firstCellNum; cellNum < lastCellNum;cellNum++){
                        Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
                    }
                    list.add(cells);
                }
            }
        }
        logger.info(gson.toJson(list));
        return list;
    }





    public static void checkFile(MultipartFile file) throws IOException{
        //判斷檔案是否存在
        if(null == file){
            throw new FileNotFoundException("檔案不存在！");
        }
        //獲得檔名
        String fileName = file.getOriginalFilename();
        //判斷檔案是否是excel檔案
        if(!fileName.endsWith(xls) && !fileName.endsWith(xlsx)){
            throw new IOException(fileName + "不是excel檔案");
        }
    }





    public static Workbook getWorkBook(MultipartFile file) {
        //獲得檔名
        String fileName = file.getOriginalFilename();
        //建立Workbook工作薄物件，表示整個excel
        Workbook workbook = null;
        try {
            //獲取excel檔案的io流
            InputStream is = file.getInputStream();
            //根據檔案字尾名不同(xls和xlsx)獲得不同的Workbook實現類物件
            if(fileName.endsWith(xls)){
                //2003
                workbook = new HSSFWorkbook(is);
            }else if(fileName.endsWith(xlsx)){
                //2007
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
            logger.info(e.getMessage());
        }
        return workbook;
    }





    public static String getCellValue(Cell cell){
        String cellValue = "";
        if(cell == null){
            return cellValue;
        }
        //把數字當成String來讀，避免出現1讀成1.0的情況
        if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC){
            cell.setCellType(Cell.CELL_TYPE_STRING);
        }
        //判斷資料的型別
        switch (cell.getCellType()){
            case Cell.CELL_TYPE_NUMERIC: //數字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING: //字串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
//                cellValue = String.valueOf(cell.getCellFormula());
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BLANK: //空值
                cellValue = "";
                break;
            case Cell.CELL_TYPE_ERROR: //故障
                cellValue = "非法字元";
                break;
            default:
                cellValue = "未知型別";
                break;
        }
        return cellValue;
    }
}