/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.content;
import java.sql.SQLException;
import org.dspace.core.Context;
import org.dspace.storage.rdbms.DatabaseManager;
import org.dspace.storage.rdbms.TableRowIterator;
/**
* This class handles the recognition of bitstream formats, using the format
* registry in the database. For the moment, the format identifier simply uses
* file extensions stored in the "BitstreamFormatIdentifier" table. This
* probably isn't a particularly satisfactory long-term solution.
*
* @author Robert Tansley
* @version $Revision$
*/
public class FormatIdentifier
{
/**
* Attempt to identify the format of a particular bitstream. If the format
* is unknown, null is returned.
*
* @param bitstream
* the bitstream to identify the format of
*
* @return a format from the bitstream format registry, or null
*/
public static BitstreamFormat guessFormat(Context context,
Bitstream bitstream) throws SQLException
{
String filename = bitstream.getName();
// FIXME: Just setting format to first guess
// For now just get the file name
// Gracefully handle the null case
if (filename == null)
{
return null;
}
filename = filename.toLowerCase();
// This isn't rocket science. We just get the name of the
// bitstream, get the extension, and see if we know the type.
String extension = filename;
int lastDot = filename.lastIndexOf('.');
if (lastDot != -1)
{
extension = filename.substring(lastDot + 1);
}
// If the last character was a dot, then extension will now be
// an empty string. If this is the case, we don't know what
// file type it is.
if (extension.equals(""))
{
return null;
}
// See if the extension is in the fileextension table
TableRowIterator tri = DatabaseManager.query(context,
"SELECT bitstreamformatregistry.* FROM bitstreamformatregistry, " +
"fileextension WHERE fileextension.extension LIKE ? " +
"AND bitstreamformatregistry.bitstream_format_id=" +
"fileextension.bitstream_format_id",
extension);
BitstreamFormat retFormat = null;
try
{
if (tri.hasNext())
{
// Return first match
retFormat = new BitstreamFormat(context, tri.next());
}
else
{
retFormat = null;
}
}
finally
{
// close the TableRowIterator to free up resources
if (tri != null)
{
tri.close();
}
}
return retFormat;
}
}