Java多种方式向图片添加自定义水印、图片转换及webp图片压缩

给个创建水印的示例：

/*** 获取水印** @param watermarkText 水印文字* @return 水印bufferimage*/public static BufferedImage getWatermark(String watermarkText) {BufferedImage measureBufferdImage = new BufferedImage(100, 100, BufferedImage.TYPE_INT_ARGB);Graphics2D measureG2d = measureBufferdImage.createGraphics();measureG2d.setFont(new Font("SimSun", Font.BOLD, 32));Rectangle2D rectangle2D = measureG2d.getFontMetrics().getStringBounds(watermarkText, null);measureG2d.dispose();int width = (int) (rectangle2D.getWidth() + 50);int height = (int) (rectangle2D.getHeight() + 50);// 创建一个 BufferedImage 对象BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);// 获取 Graphics2D 对象Graphics2D g2d = image.createGraphics();// 设置背景色g2d.setColor(new Color(0, 0, 0, 0));g2d.fillRect(0, 0, width, height);Color customColor = new Color(255, 0, 0, 50); // 半透明红色// 设置文字颜色和字体g2d.setColor(customColor);g2d.setFont(new Font("SimSun", Font.BOLD, 32));g2d.drawString(watermarkText, 25, height / 2 + 12);// 释放资源g2d.dispose();return image;}

这样可以根据一个字符串的文字生成一个水印图片

利用imageio压缩转换图片并且直接添加水印

public static File compressToWebp(File sourceImage, String watermarkText) throws IOException {BufferedImage image = ImageIO.read(new FileInputStream(sourceImage));if (StringUtils.isNotBlank(watermarkText)) {Graphics2D g2d = image.createGraphics();g2d.setFont(new Font("SimSun", Font.BOLD, 32));Rectangle2D rectangle2D = g2d.getFontMetrics().getStringBounds(watermarkText, null);int width = (int) (rectangle2D.getWidth() + 50);int height = (int) (rectangle2D.getHeight() + 50);// 设置背景色g2d.setColor(new Color(0, 0, 0, 0));Color customColor = new Color(255, 0, 0, 50); // 半透明红色// 设置文字颜色和字体g2d.setColor(customColor);g2d.setFont(new Font("SimSun", Font.BOLD, 32));g2d.drawString(watermarkText, (int) (image.getWidth() - width), image.getHeight() - height-25);// 释放资源g2d.dispose();}// Obtain a WebP ImageWriter instanceImageWriter writer = ImageIO.getImageWritersByMIMEType("image/webp").next();// Configure encoding parametersWebPWriteParam writeParam = new WebPWriteParam(writer.getLocale());writeParam.setCompressionMode(WebPWriteParam.MODE_DEFAULT);File file = new File("d:/test.webp");FileImageOutputStream fileImageOutputStream = new FileImageOutputStream(file);// Configure the output on the ImageWriterwriter.setOutput(fileImageOutputStream);// Encodewriter.write(null, new IIOImage(image, null, null), writeParam);fileImageOutputStream.flush();fileImageOutputStream.close();return file;}

将webp图片转为png图片

 public static File webpToPng(File sourceImage) throws IOException {// 读取webp格式图片BufferedImage image = ImageIO.read(sourceImage);// 写入png格式图片File pngFile = new File("d:/test.png");ImageIO.write(image, "png", pngFile);System.out.println("转换完成！");return pngFile;}

利用Thumbnails添加水印

Thumbnails.of(new File("D:/20231108011418994.jpg")).outputFormat("png").sourceRegion(Positions.BOTTOM_RIGHT, 200, 100).size(200, 100).keepAspectRatio(false).crop(Positions.BOTTOM_CENTER).watermark(Positions.BOTTOM_RIGHT, ImageIO.read(new File("D:/20231019193150520-bc.png")), 0.7f).toOutputStream(new FileOutputStream(new File("D:/20231108011418994-b.jpg")));

20231019193150520-bc.png是水印图片

相关maven包参考

<dependency><groupId>com.github.nintha</groupId><artifactId>webp-imageio-core</artifactId><version>0.1.0</version><scope>system</scope><systemPath>${project.basedir}/libs/webp-imageio-core-0.1.0.jar</systemPath></dependency>
<dependency><groupId>net.coobird</groupId><artifactId>thumbnailator</artifactId><version>0.4.20</version></dependency>