图片加水印， 水印图片随图片大小自动缩放

上代码

 // @水印图片 水印图片地址
    @Setter
    @Getter
    private static String iconPath = "https://www.lgstatic.com/i/audio1/M00/07/BA/CgHIk161EjGAXn6MAAAKzcmgVoA583.png";

    private static int standardWidth = 750;

/**
     * 添加图片水印
     * 水印固定为 @水印图片  角标
     * @param srcFile
     * @return
     */
    public static File addWaterMark(File srcFile) {

        OutputStream os = null;
        try {
            // 源图片
            String formatName = FileType.getSuffixByFilename(srcFile.getName()).substring(1);
            Image srcImg = ImageIO.read(srcFile);
            BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),
                    srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);
            int srcImgWidth = buffImg.getWidth(); // 图片宽
            int srcImgHeight = buffImg.getHeight(); // 图片高
            // 1、得到画笔对象
            Graphics2D g = buffImg.createGraphics();
            // 2、设置对线段的锯齿状边缘处理
            g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            // 3、画原图
            g.drawImage(srcImg.getScaledInstance(srcImg.getWidth(null), srcImg.getHeight(null), Image.SCALE_SMOOTH), 0, 0, null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,1.0f));
            // 4、水印图片的路径 水印图片一般为gif或者png的，这样可设置透明度
            InputStream in =  getImageStream(iconPath);
            if (in == null) {
                log.warn("iconPath 获取网络图片失败： " + iconPath);
                return srcFile;
            }
            // 5、得到Image对象
            BufferedImage imgIconBufferedImage = ImageIO.read(in);
            ImageIcon imgIcon = new ImageIcon(imgIconBufferedImage);
            // 标准尺寸边距是 20px 标准图片大小 750 比例缩放
            int margin = scale(10, srcImgWidth);
            int width =  scale(imgIcon.getIconWidth(), srcImgWidth);
            int height = scale(imgIcon.getIconHeight(), srcImgWidth);
            int positionX = srcImgWidth - width -  margin ;
            int positionY = srcImgHeight - height -  margin ;
            // 6、水印图片的位置
            g.drawImage(imgIconBufferedImage, positionX, positionY, width, height,null);
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
            // 7、释放资源
            g.dispose();
            // 8、生成图片
            os = new FileOutputStream(srcFile.getAbsolutePath());
            ImageIO.write(buffImg, formatName, os);
        } catch (Exception e) {
            log.error("Exception" , e);
        } finally {
            try {
                if (null != os) {
                    os.close();
                }
            } catch (Exception e) {
                log.error("close Exception" , e);
            }
        }
        return srcFile;
    }

    private static int scale(int w, int srcImgWidth) {

        return (w * srcImgWidth) / standardWidth;
    }

    /**
     * 获取网络图片流
     *
     * @param url
     * @return
     */
    private static InputStream getImageStream(String url) {
        try {
            HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
            connection.setReadTimeout(5000);
            connection.setConnectTimeout(5000);
            connection.setRequestMethod("GET");
            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream inputStream = connection.getInputStream();
                return inputStream;
            }
        } catch (IOException e) {
            log.error("获取网络图片出现异常，图片路径为：" + url, e);
        }
        return null;
    }

来源：oschina

链接：https://my.oschina.net/zz006/blog/4271955