java - 如何从 xlsm 加密文件中读取？

Question

我正在尝试从用密码加密的 xlsm Excel 文件中读取数据。
到目前为止，我在 Apache POI 网站上找到的方法和堆栈溢出都没有成功
这是我到目前为止所尝试的，以及我得到的异常:

    String fileName = "C:\\encryptedExcel.xlsm";
    String password = "passcode!";

        try {
            // XOR/RC4 decryption for xls
            Biff8EncryptionKey.setCurrentUserPassword(password);
            NPOIFSFileSystem fs = new NPOIFSFileSystem(new File(fileName), true);           
            HSSFWorkbook hwb = new HSSFWorkbook(fs.getRoot(), true);
        }
        catch(Exception e) {e.printStackTrace();System.err.println(e);}
        //org.apache.poi.EncryptedDocumentException: The supplied spreadsheet seems to be an Encrypted .xlsx file. It must be decrypted before use by XSSF, it cannot be used by HSSF


        try {
            Biff8EncryptionKey.setCurrentUserPassword(password);            
            Workbook workbook = new XSSFWorkbook(OPCPackage.open(fileName,PackageAccess.READ));
            Biff8EncryptionKey.setCurrentUserPassword(null);
        }
        catch(Exception e) {e.printStackTrace();System.err.println(e);}
        //org.apache.poi.openxml4j.exceptions.OLE2NotOfficeXmlFileException: The supplied data appears to be in the OLE2 Format. You are calling the part of POI that deals with OOXML (Office Open XML) Documents. You need to call a different part of POI to process this data (eg HSSF instead of XSSF)  

        try {
            BufferedInputStream bis = new BufferedInputStream(new FileInputStream(fileName));
            //if (!bis.markSupported()) {is = new PushbackInputStream(bis, 8);}
            if (POIFSFileSystem.hasPOIFSHeader(bis)) {
                POIFSFileSystem fs = new POIFSFileSystem(bis);
                EncryptionInfo info = new EncryptionInfo(fs);
                Decryptor d = Decryptor.getInstance(info);
                d.verifyPassword(password);
                //is = d.getDataStream(fs);
            }
        }
        catch(Exception e) {e.printStackTrace();}
        //throws java.io.IOException: getFileMagic() only operates on streams which support mark(int)
        //fixed by converting to BufferedInputStream
        //then throws org.apache.poi.EncryptedDocumentException: Export Restrictions in place - please install JCE Unlimited Strength Jurisdiction Policy files


        try {
            File input = new File(fileName);
            Workbook wb = WorkbookFactory.create(input, password);
        }
        catch(Exception e) {e.printStackTrace();System.err.println(e);}
        //org.apache.poi.EncryptedDocumentException: Export Restrictions in place - please install JCE Unlimited Strength Jurisdiction Policy files

Answer 1

将评论提升为答案...

首先，您应该使用 WorkbookFactory.create method which takes a password ，让 Apache POI 完成检测类型和为您设置解密的所有艰苦工作，例如

Workbook wb = WorkbookFactory.create(new File("protected.xlsx"),"SecurePassword);

其次，到目前为止，您工作中的关键错误消息是:

org.apache.poi.EncryptedDocumentException: Export Restrictions in place - please install JCE Unlimited Strength Jurisdiction Policy files

这告诉您，您有一个高贵的/笨拙的/故意部分损坏的 JVM 安装，它缺乏足够的加密支持来解密您拥有的文件。正如错误所解释的那样，您需要从 JVM 提供商处为您的 JVM 获取无限强度的 JCE 文件，并将它们安装到您所有的 Java 安装中，以便使用足够强大的加密来匹配 Excel 使用的内容

此外，Apache POI page on Encryption and Decryption也可能对您有用!