Generate QR Codes in Spring Boot Using Hutool and ZXing

Introduction

QR codes are widely used for quick sharing and login. They can be generated on the frontend or backend, and this article focuses on backend generation with Spring Boot.

History of QR Codes

Barcodes were invented in the 1950s to speed up checkout, but their limited capacity led to the development of QR codes, which store more information.

Environment Setup

Add the following Maven dependencies to your pom.xml:

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.google.zxing</groupId>
        <artifactId>core</artifactId>
        <version>3.5.2</version>
    </dependency>
    <dependency>
        <groupId>cn.hutool</groupId>
        <artifactId>hutool-all</artifactId>
        <version>5.8.35</version>
    </dependency>
</dependencies>

Basic QR Code Generation

Use QrCodeUtil.generate with content, width, height, format, and output stream.

QrCodeUtil.generate(content, width, height, format, target);

Content: text, URL, etc.

Width & Height: image dimensions.

Format: image format such as png.

Target: output destination (file or stream).

Example controller:

@GetMapping("/hutool/qrcode")
public void generateQRCodeByHutool(@RequestParam String content,
                                 HttpServletResponse response) throws Exception {
    response.setContentType("image/png");
    OutputStream os = response.getOutputStream();
    QrCodeUtil.generate(content, 300, 300, "png", os);
}

QR Code with Logo

For richer QR codes, configure a QrConfig object to set logo, error correction, margin, and other properties.

QrCodeUtil.generate(content, config, "png", target);

Example:

@GetMapping("/hutool/qrcode/custom")
public void generateCustomQRCode(@RequestParam String content,
                                 HttpServletResponse response) throws Exception {
    response.setContentType("image/png");
    OutputStream os = response.getOutputStream();
    QrConfig config = new QrConfig(500, 500);
    config.setErrorCorrection(ErrorCorrectionLevel.L);
    config.setImg("/home/seaua/Desktop/logo.png");
    config.setRound(0.2);
    config.setMargin(2);
    QrCodeUtil.generate(content, config, "png", os);
}

Creating Time‑Limited QR Links

To make QR codes expire, embed a timestamp and an MD5 signature in the URL, then validate them on the server.

public String generateQrCodeUrl(Long comboId, Long expireTime) {
    String sign = getMd5Sign(comboId, expireTime);
    return redirect + "?comboId=" + comboId + "&expire=" + expireTime + "&sign=" + sign;
}

public String getMd5Sign(Long comboId, Long expireTime) {
    return MD5.encode(comboId + ":" + expireTime + ":" + secret);
}

public Long getExpire() {
    long timeStamp = System.currentTimeMillis();
    return timeStamp + expire * 1000;
}

Conclusion

By adding Hutool and ZXing to a Spring Boot project, you can quickly generate plain or logo‑enhanced QR codes on the backend, and you can also produce expiring QR links by signing URLs with a timestamp.