File.java

/*********************************************************************
*
*      Copyright (C) 2002 Andrew Khan
*
* 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 jxl.write.biff;

import java.io.IOException;
import java.io.OutputStream;

import jxl.common.Logger;

import jxl.WorkbookSettings;
import jxl.biff.ByteData;

/**
 * A file of excel data to be written out.  All the excel data is held
 * in memory, and when the close method is called a CompoundFile object
 * is used to write the Biff oriented excel data in the CompoundFile
 * format
 */
public final class File
{
  /**
   * The logger
   */
  private static Logger logger = Logger.getLogger(File.class);

  /**
   * The data from the excel 97 file
   */
  private ExcelDataOutput data;
  /**
   * The current position within the file
   */
  private int pos;
  /**
   * The output stream
   */
  private OutputStream outputStream;
  /**
   * The initial file size
   */
  private int initialFileSize;
  /**
   * The amount to increase the growable array by
   */
  private int arrayGrowSize;
  /**
   * The workbook settings
   */
  private WorkbookSettings workbookSettings;
  /**
   * The read compound file.  This will only be non-null if there are macros
   * or other property sets of that ilk which that we should be copying
   */
  jxl.read.biff.CompoundFile readCompoundFile;

  /**
   * Constructor
   * 
   * @param os the output stream
   * @param ws the configuration settings for this workbook
   * @param rcf the rea compound file
   */
  File(OutputStream os, WorkbookSettings ws, jxl.read.biff.CompoundFile rcf)
    throws IOException
  {
    outputStream = os;
    workbookSettings = ws;
    readCompoundFile = rcf;
    createDataOutput();
  }
  
  private void createDataOutput() throws IOException
  {
    if (workbookSettings.getUseTemporaryFileDuringWrite())
    {
      data = new FileDataOutput
        (workbookSettings.getTemporaryFileDuringWriteDirectory());
    }
    else
    {
      initialFileSize = workbookSettings.getInitialFileSize();
      arrayGrowSize = workbookSettings.getArrayGrowSize();

      data = new MemoryDataOutput(initialFileSize, arrayGrowSize);
    }
  }

  /**
   * Closes the file.  In fact, this writes out all the excel data
   * to disk using a CompoundFile object, and then frees up all the memory
   * allocated to the workbook
   * 
   * @exception IOException 
   * @param cs TRUE if this should close the stream, FALSE if the application
   * closes it
   */
  void close(boolean cs) throws IOException, JxlWriteException
  {
    CompoundFile cf = new CompoundFile(data, 
                                       data.getPosition(), 
                                       outputStream, 
                                       readCompoundFile);
    cf.write();
    
    outputStream.flush();
    data.close();

    if (cs)
    {
      outputStream.close();
    }

    // Cleanup the memory a bit
    data = null;

    if (!workbookSettings.getGCDisabled())
    {
      System.gc();
    }
  }

  /**
   * Adds the biff record data to the memory allocated for this File
   * 
   * @exception IOException 
   * @param record the record to add to the excel data
   */
  public void write(ByteData record) throws IOException
  {
    byte[] bytes = record.getBytes();

    data.write(bytes);
  }

  /**
   * Gets the current position within the file
   * 
   * @return the current position
   */
  int getPos() throws IOException
  {
    return data.getPosition();
  }

  /**
   * Used to manually alter the contents of the written out data.  This
   * is used when cross-referencing cell records
   * 
   * @param pos the position to alter
   * @param newdata the data to modify
   */
  void setData(byte[] newdata, int pos) throws IOException
  {
    data.setData(newdata, pos);
  }

  /**
   * Sets a new output file.  This allows the same workbook to be
   * written to various different output files without having to
   * read in any templates again
   *
   * @param os the output stream
   */
  public void setOutputFile(OutputStream os) throws IOException
  {
    if (data != null)
    {
      logger.warn("Rewriting a workbook with non-empty data");
    }

    outputStream = os;
    createDataOutput();
  }
}