password protect excel

gistfile1.txt

public static byte[] passwordProtectExcel(byte[] inputExcel) throws IOException, GeneralSecurityException {
        // Convert the input byte array to a Workbook
        XSSFWorkbook workbook = new XSSFWorkbook(new ByteArrayInputStream(inputExcel));

        // Prepare to encrypt the workbook
        POIFSFileSystem fs = new POIFSFileSystem();
        EncryptionInfo info = new EncryptionInfo(EncryptionMode.agile);
        Encryptor enc = info.getEncryptor();
        enc.confirmPassword("password"); // Set the password here

        // Write the Workbook to an encrypted OutputStream
        try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
            workbook.write(os);
            os.close();
            try (ByteArrayOutputStream encOs = new ByteArrayOutputStream()) {
                enc.encryptDocument(os, encOs);
                encOs.close();
                fs.writeFilesystem(encOs);
                return encOs.toByteArray();
            }
        }
    }