直接上代码：效果如下图

需引入 zxing生成二维码包

        <dependency><groupId>com.google.zxing</groupId><artifactId>core</artifactId><version>3.3.3</version></dependency><dependency><groupId>com.google.zxing</groupId><artifactId>javase</artifactId><version>3.3.3</version></dependency>

方法实现如下：

controller

    //生成二维码并将其存放于本地目录@PostMapping("/generate/v1")public Response generateV1(String content){Response response=new Response();try {final String fileName=LOCALDATEFORMAT.get().format(new Date());QRCodeUtil.createCodeToFile(content,new File(RootPath),fileName+FileFormat);}catch (Exception e){response=new Response(false,e.getMessage());}return response;}

utils工具类

createCodeToFile

public static void createCodeToFile(String content, File codeImgFileSaveDir, String fileName) {try {if (StringUtils.isBlank(content) || StringUtils.isBlank(fileName)) {return;}content = content.trim();if (codeImgFileSaveDir==null || codeImgFileSaveDir.isFile()) {//二维码图片存在目录为空，默认放在桌面...codeImgFileSaveDir = FileSystemView.getFileSystemView().getHomeDirectory();}if (!codeImgFileSaveDir.exists()) {//二维码图片存在目录不存在，开始创建...codeImgFileSaveDir.mkdirs();}//核心代码-生成二维码BufferedImage bufferedImage = getBufferedImage(content,1);File codeImgFile = new File(codeImgFileSaveDir, fileName);ImageIO.write(bufferedImage, "png", codeImgFile);log.info("二维码图片生成成功：" + codeImgFile.getPath());} catch (Exception e) {e.printStackTrace();}}

核心代码：生成二维码

getBufferedImage

 private static BufferedImage getBufferedImage(String content,Integer number) throws WriterException {//com.google.zxing.EncodeHintType：编码提示类型,枚举类型Map<EncodeHintType, Object> hints = new HashMap();//EncodeHintType.CHARACTER_SET：设置字符编码类型hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");//EncodeHintType.ERROR_CORRECTION：设置误差校正//ErrorCorrectionLevel：误差校正等级，L = ~7% correction、M = ~15% correction、Q = ~25% correction、H = ~30% correction//不设置时，默认为 L 等级，等级不一样，生成的图案不同，但扫描的结果是一样的hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);//EncodeHintType.MARGIN：设置二维码边距，单位像素，值越小，二维码距离四周越近hints.put(EncodeHintType.MARGIN, 1);MultiFormatWriter multiFormatWriter = new MultiFormatWriter();BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, CODE_WIDTH, CODE_HEIGHT, hints);BufferedImage bufferedImage = new BufferedImage(CODE_WIDTH, CODE_HEIGHT, BufferedImage.TYPE_INT_BGR);for (int x = 0; x < CODE_WIDTH; x++) {for (int y = 0; y < CODE_HEIGHT; y++) {bufferedImage.setRGB(x, y, bitMatrix.get(x, y) ? FRONT_COLOR : BACKGROUND_COLOR);}}// 生成二维码图像// 创建新的BufferedImage，用于合并二维码和数字int QR_IMAGE_BOTTOM_PADDING = 30;int NUMBER_FONT_SIZE = 30;int numberWidth = bufferedImage.getWidth() / 3; // 假设数字宽度大约为二维码宽度的1/3int combinedImageHeight = CODE_HEIGHT + QR_IMAGE_BOTTOM_PADDING + NUMBER_FONT_SIZE;BufferedImage combinedImage = new BufferedImage(CODE_WIDTH, combinedImageHeight, BufferedImage.TYPE_INT_BGR);// 复制二维码图像到新图像的顶部Graphics2D g2d = combinedImage.createGraphics();g2d.drawImage(bufferedImage, 0, 0, null);// 设置字体和颜色g2d.setFont(new Font("Monospaced", Font.BOLD, NUMBER_FONT_SIZE));g2d.setColor(Color.WHITE);// 计算数字的坐标以保持居中int numberX = (CODE_WIDTH - numberWidth) / 2;int numberY = CODE_HEIGHT + QR_IMAGE_BOTTOM_PADDING;// 在新图像的底部绘制数字g2d.drawString(Integer.toString(number), numberX, numberY);g2d.dispose();return combinedImage;}