POI 加密Excel文件

        //Add password protection and encrypt the file
        final POIFSFileSystem fs = new POIFSFileSystem();
        final EncryptionInfo info = new EncryptionInfo(EncryptionMode.standard);
        //final EncryptionInfo info = new EncryptionInfo(EncryptionMode.agile, CipherAlgorithm.aes256, HashAlgorithm.sha256, -1, -1, null);
        final Encryptor enc = info.getEncryptor();

        //set the password
        enc.confirmPassword("abcdef");

        //encrypt the file
        final OPCPackage opc = OPCPackage.open(new File(path), PackageAccess.READ_WRITE);
        final OutputStream os = enc.getDataStream(fs);
        opc.save(os);
        opc.close();

        //save the file back to the filesystem
        final FileOutputStream fos = new FileOutputStream(path);
        fs.writeFilesystem(fos);
        fos.close();