java实现给图片添加图片水印

Java  /  管理员 发布于 8年前   212

具体代码：

 // 水印透明度    private static float alpha = 0.5f;           /**     * 给图片添加水印图片、可设置水印图片旋转角度     *     * @param iconPath   水印图片路径     * @param srcImgPath 源图片路径     * @param location   水印图片位置     * @param degree     水印图片旋转角度     */    public static void markImageByIcon(HttpServletRequest request, HttpServletResponse response,   String iconPath, String srcImgPath, String location, Integer degree) {        OutputStream os = null;        try {Image srcImg = ImageIO.read(new File(srcImgPath));BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),        srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);// 得到画笔对象Graphics2D g = buffImg.createGraphics();// 设置对线段的锯齿状边缘处理g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,        RenderingHints.VALUE_INTERPOLATION_BILINEAR);g.drawImage(        srcImg.getScaledInstance(srcImg.getWidth(null),    srcImg.getHeight(null), Image.SCALE_SMOOTH), 0, 0,        null);// 设置水印旋转角度（默认对角线角度）if (null != degree) {    g.rotate(Math.toRadians(degree), (double) buffImg.getWidth() / 2, (double) buffImg.getHeight() / 2);} else {    //根据三角形相关定理，计算对角线角度    double lengthOfDiagonal = Math.sqrt(buffImg.getWidth() * buffImg.getWidth() + buffImg.getHeight() * buffImg.getHeight());    double v = (Math.pow(buffImg.getWidth(), 2) + Math.pow(lengthOfDiagonal, 2) - Math.pow(buffImg.getHeight(), 2)) / (2 * buffImg.getWidth() * lengthOfDiagonal);    double acos = Math.acos(v);    double myDegree = Math.toDegrees(acos);    g.rotate(-Math.toRadians(myDegree), (double) buffImg.getWidth() / 2, (double) buffImg.getHeight() / 2);}// 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ImageIcon imgIcon = new ImageIcon(iconPath);Image img = imgIcon.getImage();g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,        alpha));// 水印图片的位置int x = 0, y = 0;if (StringUtils.equals(location, "left-top")) {    x = 30;    y = 30;} else if (StringUtils.equals(location, "right-top")) {    x = buffImg.getWidth() - img.getWidth(null) - 30;    y = 30;} else if (StringUtils.equals(location, "left-bottom")) {    x += 30;    y = buffImg.getHeight() - img.getHeight(null) - 30;} else if (StringUtils.equals(location, "right-bottom")) {    x = buffImg.getWidth() - img.getWidth(null) - 30;    y = buffImg.getHeight() - img.getHeight(null) - 30;} else {    x = (buffImg.getWidth() - img.getWidth(null)) / 2;    y = (buffImg.getHeight() - img.getHeight(null)) / 2;}g.drawImage(img, x, y, null);g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));g.dispose();// os = new FileOutputStream(targerPath);os = response.getOutputStream();ImageIO.write(buffImg, "JPG", os);        } catch (Exception e) {e.printStackTrace();        } finally {try {    if (null != os)        os.close();} catch (Exception e) {    e.printStackTrace();}        }    }

（视频教程推荐：java视频）

smbfile时也可以写成这样：

// 展示时 添加水印public void showRemarkImage(String filePath, String iconPath, HttpServletRequest request, HttpServletResponse response) {InputStream is = null;OutputStream os = null;ByteArrayOutputStream out = new ByteArrayOutputStream();  try {SmbFile smbFile = new SmbFile(filePath);is = smbFile.getInputStream();os = response.getOutputStream();Image srcImg = ImageIO.read(is);BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),        srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);// 得到画笔对象Graphics2D g = buffImg.createGraphics();// 设置对线段的锯齿状边缘处理g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,        RenderingHints.VALUE_INTERPOLATION_BILINEAR);g.drawImage(srcImg.getScaledInstance(srcImg.getWidth(null), srcImg.getHeight(null), Image.SCALE_SMOOTH), 0, 0, null);         // 旋转角度处理（根据三角形相关定理，计算对角线角度）//double lengthOfDiagonal = Math.sqrt(buffImg.getWidth() * buffImg.getWidth() + buffImg.getHeight() * buffImg.getHeight());//double v = (Math.pow(buffImg.getWidth(), 2) + Math.pow(lengthOfDiagonal, 2) - Math.pow(buffImg.getHeight(), 2)) / (2 * buffImg.getWidth() * lengthOfDiagonal);//double acos = Math.acos(v);//double myDegree = Math.toDegrees(acos);//g.rotate(-Math.toRadians(myDegree), (double) buffImg.getWidth() / 2, (double) buffImg.getHeight() / 2);          // 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ImageIcon imgIcon = new ImageIcon(iconPath);Image img = imgIcon.getImage();g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));// 水印图片居中int x = 0, y = 0;       x = (buffImg.getWidth() - img.getWidth(null)) / 2;y = (buffImg.getHeight() - img.getHeight(null)) / 2;          g.drawImage(img, x, y, null);g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));g.dispose();       ImageIO.write(buffImg, "png", out);         byte[] b = out.toByteArray();response.addHeader("Content-Length", String.valueOf(b.length));      os.write(b, 0, b.length);os.flush();       } catch (Exception e) {LogUtil.error("附件下载失败，时间：" + DateUtil.formatToDateTimeText(new Date()) + "原因：" + e.getMessage());//throw new ApplicationException("文件读取失败：" + e.getMessage(), e);} finally {IOUtils.closeQuietly(is);IOUtils.closeQuietly(os);IOUtils.closeQuietly(out);}}

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