java Spring Boot generates image QR code

First we need to introduce dependencies
and insert them into pom.xml

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.4.1</version>
</dependency>

Then write the function directly in the interface class

@GetMapping(value = "/qrcode/{text}")
public void generateQRCode(@PathVariable("text") String text, HttpServletResponse response) throws IOException, WriterException {
    
    
    response.setContentType(MediaType.IMAGE_PNG_VALUE);
    OutputStream outputStream = response.getOutputStream();

    Map<EncodeHintType, Object> hints = new HashMap<>();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");

    BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, 200, 200, hints);
    MatrixToImageWriter.writeToStream(bitMatrix, "PNG", outputStream);

    outputStream.flush();
    outputStream.close();
}

Then directly access the port+prefix configuration/qrcode/the QR code text content to be generated

For example, here I visit
http://localhost/books/qrcode/1992
and the interface will return a QR code to us. Because the CSDN platform does not support banning QR code images, I use a brush to crack it to avoid being harmonized,

and then use my mobile phone Scan the QR code

to bring out the content of our text