[jdom-interest] fail to output Document to encrypted file

[ÁÎÃûѧ]

Using "flowfish", I encrypted an xml file which is from a Document instance and
successfully rebuilt the Document instance from the encypted file. Then before
closing my application, I output the Document instance to an encrypted file. The
code is as below, but the resulting file is not all right and seems to lack a few
bytes(especially the last bytes) after it is decrypted.

    try
    {
      String indent = " ";
      boolean newLines = true;
      XMLOutputter outp = new XMLOutputter(indent, newLines, "GB2312");
      outp.setTextTrim(true);
      // doc is a correct Document instance
      // catFilePath is a String instance
      // cipher is a Cipher instance for encrypting
      outp.output(doc,new CipherOutputStream(
                      new FileOutputStream(catFilePath),cipher));
    }
    catch (Exception e) {e.printStackTrace();}

If I change indent,newLines,or remove "outp.setTextTrim(true)", the resulting file
changes a little accordingly.