package common;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import org.neo4j.commons.iterator.PrefetchingIterator;
public class CsvFileReader extends PrefetchingIterator<String[]>
{
private final BufferedReader reader;
private String delimiter;
public CsvFileReader( File file ) throws IOException
{
this( file, null );
}
public CsvFileReader( File file, String delimiter ) throws IOException
{
this.delimiter = delimiter;
this.reader = new BufferedReader( new FileReader( file ) );
}
@Override
protected String[] fetchNextOrNull()
{
try
{
String line = reader.readLine();
if ( line == null )
{
close();
return null;
}
if ( delimiter == null )
{
delimiter = figureOutDelimiter( line );
}
return line.split( delimiter );
}
catch ( IOException e )
{
throw new RuntimeException( e );
}
}
protected String figureOutDelimiter( String line )
{
String[] candidates = new String[] { "\t", "," };
for ( String candidate : candidates )
{
if ( line.indexOf( candidate ) > -1 )
{
return candidate;
}
}
throw new RuntimeException( "Couldn't guess delimiter in '"
+ line + "'" );
}
public void close() throws IOException
{
reader.close();
}
}