问在gui java中上传大型.xlsx文件

EN

void fillData(File file) {
    int index = -1;
    XSSFWorkbook workbook = null;
    try {
        try {
            String f = file.getPath();
            File file1 = new File(f);
            OPCPackage opcPackage = OPCPackage.open(file1);
            workbook = new XSSFWorkbook(opcPackage);
        } catch (IOException ex) {
            Logger.getLogger(ProjectApp3.class.getName()).log(Level.SEVERE, null, ex);
        }

        String[] strs = new String[workbook.getNumberOfSheets()];
        //get all sheet names from selected workbook
        for (int i = 0; i < strs.length; i++) {
            strs[i] = workbook.getSheetName(i);
        }
        JFrame frame = new JFrame("Input Dialog");
        //select sheet
        String selectedsheet = (String) JOptionPane.showInputDialog(
                frame, "Which worksheet you want to import ?", "Select Worksheet",
                JOptionPane.QUESTION_MESSAGE, null, strs, strs[0]);

        if (selectedsheet != null) {
            for (int i = 0; i < strs.length; i++) {
                if (workbook.getSheetName(i).equalsIgnoreCase(selectedsheet))
                    index = i;
            }
            XSSFSheet sheet = workbook.getSheetAt(index);
            XSSFRow row = sheet.getRow(0);
            //import headers data
            headers.clear();
            for (int i = 0; i < row.getLastCellNum(); i++) {
                XSSFCell cell1 = row.getCell(i);
                headers.add(cell1.toString());
            }
            //import data
            data1.clear();
            for (int j = 1; j < sheet.getLastRowNum() + 1; j++) {
                Vector d = new Vector();
                row = sheet.getRow(j);
                int noofrows = row.getLastCellNum();
                for (int i = 0; i < noofrows; i++) {    //To handle empty excel cells 
                    XSSFCell cell = row.getCell(i,
                            org.apache.poi.ss.usermodel.Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
                    d.add(cell.toString());
                }
                d.add("\n");
                data1.add(d);

            }
        } else {
            return;
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}