selenium 元素截图 ifrema定位

public static BufferedImage createElementImage(WebElement webElement,
			WebDriver webDriver,int x,int y) throws IOException {
		ByteArrayInputStream by = null;
		BufferedImage croppedImage = null;
		try {
			long s = System.currentTimeMillis();
			// 获得webElement的位置和大小。
			Point location = webElement.getLocation();
			Dimension size = webElement.getSize();
			by = new ByteArrayInputStream(takeScreenshot(webDriver));
			// 创建全屏截图。
			BufferedImage originalImage = ImageIO.read(by);
			// 截取webElement所在位置的子图。
			croppedImage = originalImage.getSubimage(location.getX()+x,
					location.getY()+y, size.getWidth(), size.getHeight());
			long e = System.currentTimeMillis();
			logger.error("获取webelement 验证码 流的时间为：" + (e - s));
		} finally {
			if(by!=null){
				by.close();	
			}
		}
		return croppedImage;
	}