JAVA

qr code spring boot

package dev.simplesolution.generateqr.service.impl;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import dev.simplesolution.generateqr.service.QRCodeService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

@Service
public class QRCodeServiceImpl implements QRCodeService {

    private Logger logger = LoggerFactory.getLogger(QRCodeServiceImpl.class);

    @Override
    public byte[] generateQRCode(String qrContent, int width, int height) {
        try {
            QRCodeWriter qrCodeWriter = new QRCodeWriter();
            BitMatrix bitMatrix = qrCodeWriter.encode(qrContent, BarcodeFormat.QR_CODE, width, height);
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            MatrixToImageWriter.writeToStream(bitMatrix, "PNG", byteArrayOutputStream);
            return byteArrayOutputStream.toByteArray();
        } catch (WriterException e) {
            logger.error(e.getMessage(), e);
        } catch (IOException e) {
            logger.error(e.getMessage(), e);
        }
        return null;
    }
}

qr code spring boot

package dev.simplesolution.generateqr.controller;

import dev.simplesolution.generateqr.service.QRCodeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;

@Controller
public class QRCodeController {

    @Autowired
    private QRCodeService qrCodeService;

    @RequestMapping("/")
    public String index() {
        return "index";
    }

    @PostMapping("/showQRCode")
    public String showQRCode(String qrContent, Model model) {
        model.addAttribute("qrCodeContent", "/generateQRCode?qrContent=" + qrContent);
        return "show-qr-code";
    }

    @GetMapping("/generateQRCode")
    public void generateQRCode(String qrContent, HttpServletResponse response) throws IOException {
        response.setContentType("image/png");
        byte[] qrCode = qrCodeService.generateQRCode(qrContent, 500, 500);
        OutputStream outputStream = response.getOutputStream();
        outputStream.write(qrCode);
    }
}