code: public BufferedImage drawTileQueryAll(int x, int y, int zoom) {
  
  		BoundingBox boundingBox = TileBoundingBoxUtils
  				.getWebMercatorBoundingBox(x, y, zoom);
  
  		BufferedImage image = null;
  
  		// Query for all features
  		FeatureResultSet resultSet = featureDao.queryForAll();
  
  		try {
  
  			int totalCount = resultSet.getCount();
  
  			// Draw if at least one geometry exists
  			if (totalCount > 0) {
  
  				if (maxFeaturesPerTile == null
  						|| totalCount <= maxFeaturesPerTile) {
  
  					// Draw the tile image
  					image = drawTile(zoom, boundingBox, resultSet);
  
  				} else if (maxFeaturesTileDraw != null) {
  
  					// Draw the unindexed max features tile
  					image = maxFeaturesTileDraw.drawUnindexedTile(tileWidth,
  							tileHeight, totalCount, resultSet);
  				}
  
  			}
  		} finally {
  			resultSet.close();
  		}
  
  		return image;
  	}
docs: Draw a tile image from the x, y, and zoom level by querying all features.
  This could be very slow if there are a lot of features
  
  @param x
  x coordinate
  @param y
  y coordinate
  @param zoom
  zoom level
  @return drawn image, or null