package pl.wroc.pwr.string;

import java.io.File;

import pl.wroc.pwr.IOperator;
import pl.wroc.pwr.system.Consts;

public class ExtractFileExtension implements IOperator<String>
{
	/**
	 * 
	 */
	private static final long serialVersionUID = -1500722797899186720L;
	
	private File file;
	
	public ExtractFileExtension( File file ) {
		this.file = file;
	}
		
	public void setFile( File file ) {
		this.file = file;
	}

	public String apply( ) {
		String name = this.file.getName( );
		int index = name.lastIndexOf( Consts.DOT );
		if ( index >= 0 )
		{
			return name.substring( index + 1 );
		}
		return Consts.EMPTY;
	}
}