使用apache poi和java从单元格读取更快

Question

您好我正在从Excel中的单元格中读取实时值。这些值来自Siemens S7 plc。如果它们进展得足够慢，我可以得到它们。例如，如果我选择一个保存分钟的单元格，则在读取时会正确更新。但是，当我查看包含秒的单元格时，它每30秒才会更新一次。我总是得到15或45.我有没有办法每秒钟获得细胞内容？

public static void main(String[] args) throws InterruptedException {
    try {
        POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream(filename));
        HSSFWorkbook hssfworkbook = new HSSFWorkbook(fs);
        HSSFSheet sheet = hssfworkbook.getSheetAt(0);
        HSSFCell currentStateCell=null;
        HSSFRow currentRow = sheet.getRow(34);
        currentStateCell = currentRow.getCell(0);

    while(true) {   
        Thread.sleep(800);
        fs = new POIFSFileSystem(new FileInputStream(filename)); 
        hssfworkbook = new HSSFWorkbook(fs);
        sheet = hssfworkbook.getSheetAt(0);
        //this row contains the seconds cell(cell A,33)
        currentRow = sheet.getRow(33);
        currentStateCell = currentRow.getCell(0);
        //this print out willgive me either 15.0 or 45.0 I want 1:60
        System.out.println(currentStateCell.getNumericCellValue());
      }} catch (IOException ex) {
        Logger.getLogger(ReadExcelExample.class.getName()).log(Level.SEVERE, null, ex);
    }
}

}