/**
   * Loop through the ZIP file, copying its entries into a new, temporary ZIP file, skipping the
   * entry to be deleted. Then replace the original file with the new one.
   */
  protected Integer deleteEntry() throws XMLDataStoreException {
    try {
      ZipInputStream inStream = this.buildZipInputStream();
      File outFile = this.buildTempFile();
      ZipOutputStream outStream = new ZipOutputStream(new FileOutputStream(outFile));

      byte[] buffer = new byte[32768];
      int inCount = 0;
      int outCount = 0;

      // copy all the entries except the one to be deleted
      ZipEntry entry = inStream.getNextEntry();
      while (entry != null) {
        inCount++;
        if (!this.getZipEntryName().equals(entry.getName())) {
          outCount++;
          outStream.putNextEntry(entry);
          int byteCount;
          while ((byteCount = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, byteCount);
          }
          outStream.closeEntry();
        }
        entry = inStream.getNextEntry();
      }
      inStream.close();
      if (outCount == 0) {
        // add a dummy record to an empty file so we can close it
        // this is required by ZipOutputStream
        outStream.putNextEntry(new ZipEntry("delete.txt"));
        outStream.write(
            "This file is a place-holder. The containing ZIP file should be deleted.".getBytes());
        outStream.closeEntry();
      }
      outStream.close();
      if (outCount == inCount) {
        // no entries were removed - just delete the temp file
        outFile.delete();
      } else {
        // at least one entry removed - delete the original file
        this.getFile().delete();
        if (outCount == 0) {
          // NO entries remain - just delete the temp file too
          outFile.delete();
        } else {
          // entries remain - replace original file with temp file
          outFile.renameTo(this.getFile());
        }
      }
      return new Integer(inCount - outCount); // should be 0 or 1
    } catch (IOException ex) {
      throw XMLDataStoreException.ioException(ex);
    }
  }
  /**
   * Rename the ZIP file to a temporary file, then copy its entries back into the original ZIP file,
   * leaving the stream open and returning it.
   */
  protected Writer buildWriteStream(boolean entryShouldExist) throws XMLDataStoreException {
    try {
      File inFile = this.buildTempFile();
      inFile.delete(); // the file actually gets created - delete it
      boolean renameSucceeded = this.getFile().renameTo(inFile);
      ZipInputStream inStream = this.buildZipInputStream(inFile);
      ZipOutputStream outStream = this.buildZipOutputStream();

      boolean entryActuallyExists = false;
      byte[] buffer = new byte[32768];
      ZipEntry entry = inStream.getNextEntry();
      while (entry != null) {
        boolean weWantToWriteTheEntry = true;
        if (this.getZipEntryName().equals(entry.getName())) {
          entryActuallyExists = true;

          // if we were expecting the entry, skip it;
          // if we were NOT expecting the entry, allow it to be rewritten
          // so the file is restored to its original condition
          if (entryShouldExist) {
            weWantToWriteTheEntry = false;
          }
        }
        if (weWantToWriteTheEntry) {
          outStream.putNextEntry(entry);
          int byteCount;
          while ((byteCount = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, byteCount);
          }
          outStream.closeEntry();
        }
        entry = inStream.getNextEntry();
      }

      // close and delete the temporary file
      inStream.close();
      inFile.delete();
      // check for invalid state
      if (entryShouldExist != entryActuallyExists) {
        outStream.close(); // close it since we will not be returning it
        // need more helpful exceptions here
        if (entryActuallyExists) {
          throw XMLDataStoreException.fileAlreadyExists(new File(this.getZipEntryName()));
        } else {
          throw XMLDataStoreException.fileNotFound(new File(this.getZipEntryName()), null);
        }
      }
      outStream.putNextEntry(new ZipEntry(this.getZipEntryName()));
      return new OutputStreamWriter(outStream);
    } catch (IOException ex) {
      throw XMLDataStoreException.ioException(ex);
    }
  }