Apache POI 加密的 xlsx 无法在 excel 中打开

Question

我正在尝试使用 Apache POI 创建加密的 xlsx 文件。这是我的代码，它运行得很好：

public static void Encrypt(String data) throws IOException, GeneralSecurityException, InvalidFormatException {

    Workbook wb = new XSSFWorkbook();
    Sheet sheet1 = wb.createSheet("sheet1");
    sheet1.createRow(0).createCell(0).setCellValue(data);
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    wb.write(bos);
    bos.close();

    POIFSFileSystem fs = new POIFSFileSystem();
    EncryptionInfo info = new EncryptionInfo(EncryptionMode.agile, CipherAlgorithm.aes256, HashAlgorithm.sha512, 256, 16, ChainingMode.cbc);
    Encryptor enc = info.getEncryptor();
    enc.confirmPassword("pass");

    OPCPackage opc = OPCPackage.open(new ByteArrayInputStream(bos.toByteArray()));
    OutputStream os = enc.getDataStream(fs);
    opc.save(os);
    opc.close();

    FileOutputStream fos = new FileOutputStream("provawrite.xlsx");
    fs.writeFilesystem(fos);
    fos.close();
}

问题是当我打开生成的文件时，excel 一直抱怨文件已损坏。我还尝试EncryptionInfo使用不同的加密模式更改实例化，但没有任何变化。

有人可以给我一个提示吗？！？

Answer 1

在写出文件系统之前必须关闭加密的输出流。在你的情况下，它缺乏os.close();后opc.save(os);。

但是为什么要绕道而行ByteArrayOutputStream呢？

以下对我有用：

import java.io.*;
import org.apache.poi.poifs.filesystem.*;
import org.apache.poi.poifs.crypt.*;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class XSSFEncryption {

 public static void doEncrypt(String data) throws Exception {

  POIFSFileSystem fs = new POIFSFileSystem();
  EncryptionInfo info = new EncryptionInfo(EncryptionMode.agile);

  Encryptor enc = info.getEncryptor();
  enc.confirmPassword("pass");

  Workbook workbook = new XSSFWorkbook();
  Sheet sheet = workbook.createSheet("sheet1");
  sheet.createRow(0).createCell(0).setCellValue(data);

  // write the workbook into the encrypted OutputStream
  OutputStream encos = enc.getDataStream(fs);
  workbook.write(encos);
  workbook.close();
  encos.close(); // this is necessary before writing out the FileSystem

  OutputStream os = new FileOutputStream("provawrite.xlsx");
  fs.writeFilesystem(os);
  os.close();
  fs.close();
 }

 public static void main(String[] args) throws Exception {
  doEncrypt("Test");
 }
}