public class TileData
{
    public static final char HASH = '#';
    public static final char SPACE = '.';
    
    public static final String TILE_ID = "Tile ";
    
    private TileData ()
    {
    }
}
public class TileData
{
    public static final char HASH = '#';
    public static final char SPACE = '.';  // unoccupied
    
    public static final String TILE_ID = "Tile ";
    
    private TileData ()
    {
    }
}
Update TileData.java