net.sf.mpxj.mpp.EncryptedDocumentInputStream Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of mpxj Show documentation

Library that provides facilities to allow project information to be manipulated in Java and .Net. Supports a range of data formats: Microsoft Project Exchange (MPX), Microsoft Project (MPP,MPT), Microsoft Project Data Interchange (MSPDI XML), Microsoft Project Database (MPD), Planner (XML), Primavera (PM XML, XER, and database), Asta Powerproject (PP, MDB), Asta Easyplan (PP), Phoenix Project Manager (PPX), FastTrack Schedule (FTS), and the Standard Data Exchange Format (SDEF).

There is a newer version: 13.8.0

Show newest version

/*
 * file:       EncryptedDocumentInputStream.java
 * author:     Jon Iles
 * copyright:  (c) Packwood Software 2002-2007
 * date:       20/10/2007
 */

/*
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

package net.sf.mpxj.mpp;

import java.io.IOException;
import java.io.InputStream;

import org.apache.poi.poifs.filesystem.DocumentEntry;
import org.apache.poi.poifs.filesystem.DocumentInputStream;

/**
 * This class wraps the POI {@link DocumentInputStream} class
 * to allow data to be decrypted before passing
 * it back to the caller.
 */
final class EncryptedDocumentInputStream extends InputStream
{
   /**
    * Constructor.
    *
    * @param entry file entry
    * @param mask the mask used to decrypt the stream.
    */
   public EncryptedDocumentInputStream(DocumentEntry entry, int mask)
      throws IOException
   {
      m_dis = new DocumentInputStream(entry);
      m_mask = mask;
   }

   @Override public int read() throws IOException
   {
      int value = m_dis.read();
      value ^= m_mask;
      return (value);
   }

   @Override public int read(byte[] b, int off, int len) throws IOException
   {
      int result = m_dis.read(b, off, len);
      for (int loop = 0; loop < len; loop++)
      {
         b[loop + off] ^= m_mask;
      }
      return result;
   }

   @Override public int available()
   {
      return m_dis.available();
   }

   @Override public void close()
   {
      m_dis.close();
   }

   @Override public synchronized void mark(int readlimit)
   {
      m_dis.mark(readlimit);
   }

   @Override public boolean markSupported()
   {
      return m_dis.markSupported();
   }

   @Override public synchronized void reset()
   {
      m_dis.reset();
   }

   @Override public long skip(long n) throws IOException
   {
      return m_dis.skip(n);
   }

   private final DocumentInputStream m_dis;
   private final int m_mask;
}