分享一个Java实现生成二维码的功能，引入的技术为google的zxing。

一、Maven引入

<!-- zxing二维码 -->
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.5.2</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.5.2</version>
</dependency>

二、书写工具类

//通用二维码生成工具类
public class QrCodeUtils {

    /**
     * 生成普通二维码并保存为图片文件
     *
     * @param content  二维码内容
     * @param filePath 保存路径（绝对路径）
     * @param width    宽度
     * @param height   高度
     */
    public static void generateQrCode(String content, String filePath, Integer width, Integer height)throws Exception {
        //编码参数设置
        HashMap<EncodeHintType, Object> hints = new HashMap<>();
        // 编码类型
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        // 边距
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix encode = new MultiFormatWriter().encode(
                content,
                BarcodeFormat.QR_CODE,
                width,
                height,
                hints
        );
        Path path = new File(filePath).toPath();
        MatrixToImageWriter.writeToPath(encode, "PNG", path);
    }
    /**
     * 生成带 Logo 的二维码
     *
     * @param content   二维码内容
     * @param logoPath  logo 图片路径
     * @param outputPath 输出二维码路径
     */
    public static void generateQrCodeWithLogo(String content, String logoPath, String outputPath) throws Exception {
        int width = 300;
        int height = 300;

        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.MARGIN, 1);
        // 容错率高，避免 logo 遮挡
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

        BitMatrix bitMatrix = new MultiFormatWriter().encode(
                content,
                BarcodeFormat.QR_CODE,
                width,
                height,
                hints
        );

        // 生成二维码图像
        BufferedImage qrImage = MatrixToImageWriter.toBufferedImage(bitMatrix, new MatrixToImageConfig());

        // 加载 logo 图片
        BufferedImage logo = ImageIO.read(new File(logoPath));

        int logoWidth = qrImage.getWidth() / 5;
        int logoHeight = qrImage.getHeight() / 5;

        // 计算 logo 放置位置（居中）
        int x = (qrImage.getWidth() - logoWidth) / 2;
        int y = (qrImage.getHeight() - logoHeight) / 2;

        // 合并图片
        Graphics2D g = qrImage.createGraphics();
        g.drawImage(logo, x, y, logoWidth, logoHeight, null);
        g.dispose();

        ImageIO.write(qrImage, "PNG", new File(outputPath));
    }
}

三、具体实现

public class QrCodeController {
    public static void main(String[] args) throws Exception {
        String content = "https://zhaoruochen.com/";
        String savePath = "D:/qrcode/测试.png";

        QrCodeUtils.generateQrCode(content, savePath, 300, 300);
        System.out.println("二维码生成成功！");
    }
//    public static void main(String[] args) throws Exception {
//        String content = "cs";
//        String logo = "D:/qrcode/logo/logo.jpg";
//        String output = "D:/qrcode/带logo的二维码.png";
//
//        QrCodeUtils.generateQrCodeWithLogo(content, logo, output);
//        System.out.println("带Logo的二维码已生成！");
//   }
}