Heim >Java >JavaErste Schritte >Java implementiert das Hinzufügen von Bildwasserzeichen zu Bildern
Spezifischer Code:
// 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(); } } }
(Video-Tutorial-Empfehlung: Java-Video)
smbfile kann auch so geschrieben werden:
// 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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