先看一下生成效果

普通二维码

普通带文本二维码

带logo二维码

带logo带文本二维码

直接上代码

这里主要是用的第三方工具生成二维码的，所以我们需要先引入 jar 包

		<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>

虽然二维码生成依靠的是第三方工具，但是 logo 和文本还是需要我们自己添加进去的

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author Sakura
 * @date 2024/9/30 14:11
 */
public class QRCodeGenerator {

    /**
     * @description: 生成二维码
     * @param text 二维码内容
     * @param remark 二维码描述
     * @param path 二维码保存路径
     * @param logoFile 二维码logo文件
     * @param width 二维码宽度
     * @param height 二维码高度
     */
    public static void generateQRCode(String text, String remark, String path, File logoFile, int width, int height) throws Exception {
        // 设置二维码参数
        Map<EncodeHintType, Object> hints = new ConcurrentHashMap<>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 高纠错等级
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.MARGIN, 1); // 边框

        // 创建BitMatrix对象
        BitMatrix matrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);

        // 动态计算增加的高度用于备注文本
        int textHeight = (remark != null && !remark.isEmpty()) ? 30 : 0;

        // 创建带有二维码和备注文本的 BufferedImage
        BufferedImage qrImage = new BufferedImage(width, height + textHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = qrImage.createGraphics();
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, width, height + textHeight); // 设置背景为白色

        // 绘制二维码到 BufferedImage
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                qrImage.setRGB(x, y, matrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }

        // 添加Logo到二维码
        if (logoFile != null && logoFile.exists()) {
            addLogoToQRCode(qrImage, logoFile, width, height);
        }

        // 添加备注文本
        if (remark != null && !remark.isEmpty()) {
            addTextToQRCode(qrImage, remark, width, height, textHeight);
        }

        // 保存二维码图片到指定路径
        Path filePath = Paths.get(path);
        Files.createDirectories(filePath.getParent()); // 确保目录存在
        ImageIO.write(qrImage, "PNG", new File(path));
    }

    // 添加Logo到二维码
    private static void addLogoToQRCode(BufferedImage qrImage, File logoFile, int qrWidth, int qrHeight) throws Exception {
        // 读取Logo图片
        BufferedImage logoImage = ImageIO.read(logoFile);

        // 计算Logo的缩放比例和新宽高
        int logoWidth = Math.min(logoImage.getWidth(), qrWidth / 5);  // 缩小至二维码宽度的1/5
        int logoHeight = Math.min(logoImage.getHeight(), qrHeight / 5);

        // 计算Logo绘制的左上角位置，使其居中
        int x = (qrWidth - logoWidth) / 2;
        int y = (qrHeight - logoHeight) / 2;

        // 绘制白色边框背景
        Graphics2D g2 = qrImage.createGraphics();
        g2.setColor(Color.WHITE);
        g2.fillRoundRect(x - 5, y - 5, logoWidth + 10, logoHeight + 10, 10, 10);

        // 绘制Logo到二维码中心
        g2.drawImage(logoImage.getScaledInstance(logoWidth, logoHeight, Image.SCALE_SMOOTH), x, y, null);
        g2.dispose();
    }

    // 在二维码底部添加文本
    private static void addTextToQRCode(BufferedImage image, String text, int width, int qrHeight, int textHeight) {
        Graphics2D g2 = image.createGraphics();
        g2.setColor(Color.BLACK);
        g2.setFont(new Font("Arial", Font.PLAIN, 20));  // 设置字体

        // 获取文本的宽度以便居中对齐
        FontMetrics fm = g2.getFontMetrics();
        int textWidth = fm.stringWidth(text);
        int x = (width - textWidth) / 2;

        // 调整 y 坐标位置，将文本稍微上移
        int padding = 10;  // 增加一个 padding 值，让文本上移一点，避免贴得太近
        int y = qrHeight + (textHeight - fm.getHeight()) / 2 + fm.getAscent() - padding;

        // 绘制文本
        g2.drawString(text, x, y);
        g2.dispose(); // 释放资源
    }
}

然后就可以在我们的业务里面调用了

@RestController
@RequestMapping("/qrcode")
@Module("base")
@Api(value = "二维码api", tags = {"二维码管理"})
public class QrcodeController {

    @Autowired
    private QrcodeService qrcodeService;

    @PostMapping("/generate")
    @ApiOperation(value = "生成二维码", response = ApiResult.class)
    public ApiResult<String> generate(@RequestParam(value = "text") String text,
                                      @RequestParam(value = "remark", required = false) String remark,
                                      @RequestParam(value = "width", required = false, defaultValue = "300") Integer width,
                                      @RequestParam(value = "height", required = false, defaultValue = "300") Integer height) throws Exception {
        String path = qrcodeService.generate(text, remark, width, height);
        return ApiResult.ok(path);
    }

    @PostMapping("/generateWithLogo")
    @ApiOperation(value = "生成带logo二维码", response = ApiResult.class)
    public ApiResult<String> generateWithLogo(@RequestPart("file") MultipartFile file,
                                              @RequestParam(value = "text") String text,
                                              @RequestParam(value = "remark", required = false) String remark,
                                              @RequestParam(value = "width", required = false, defaultValue = "300") Integer width,
                                              @RequestParam(value = "height", required = false, defaultValue = "300") Integer height) throws Exception {
        String path = qrcodeService.generateWithLogo(file, text, remark, width, height);
        return ApiResult.ok(path);
    }

    /**
     * 下载文件
     */
    @GetMapping("/{code}")
    @ApiOperation(value = "下载")
    public void download(HttpServletResponse response, @PathVariable("code") String code) throws Exception {
        qrcodeService.download(response, code);
    }

}

@Service
@Log
public class QrcodeServiceImpl implements QrcodeService {

    @Value("${local.host}")
    String LOCAL_HOST;

    // 文件存放路径跟jar包同目录下/resources/files/
    private static final String LOCAL_FILE_PATH = "./resources/qrcode/";
    @Override
    public String generate(String text, String remark, Integer width, Integer height) throws Exception {
        // 随机生成一个文件名
        String code = RandomStringUtils.randomAlphanumeric(32);
        QRCodeGenerator.generateQRCode(text, remark, LOCAL_FILE_PATH + code + ".png", null, width, height);
        return LOCAL_HOST + "qrcode/" + code;
    }

    @Override
    public String generateWithLogo(MultipartFile file, String text, String remark, Integer width, Integer height) throws Exception {
        // 随机生成一个文件名
        String code = RandomStringUtils.randomAlphanumeric(32);

        // 创建临时文件，确保文件路径正确
        File convFile = File.createTempFile("logo_", "_" + file.getOriginalFilename());
        file.transferTo(convFile);

        // 调用生成二维码的方法
        QRCodeGenerator.generateQRCode(text, remark, LOCAL_FILE_PATH + code + ".png", convFile, width, height);

        // 删除临时文件
        convFile.delete();

        return LOCAL_HOST + "qrcode/" + code;
    }

    @Override
    public void download(HttpServletResponse response, String code) throws Exception {
        File downloadFile = new File(LOCAL_FILE_PATH + code + ".png");
        if (!downloadFile.exists() || downloadFile.length() == 0) {
            throw new BusinessException(500, "文件不存在");
        }

        // 确定文件的Content-Type
        String mimeType = Files.probeContentType(downloadFile.toPath());
        if (mimeType == null) {
            mimeType = "application/octet-stream"; // 默认类型
        }

        response.setContentType(mimeType);
        response.addHeader("Content-Length", String.valueOf(downloadFile.length()));
        response.addHeader("Content-Disposition", "attachment; filename=\"" + code + ".png\"");

        try (InputStream is = new FileInputStream(downloadFile);
             OutputStream os = response.getOutputStream()) {

            IOUtils.copy(is, os);
            os.flush(); // 确保数据已写入输出流
        } catch (IOException e) {
            log.info("下载图片发生IO异常");
            e.printStackTrace();
            throw new BusinessException(500, "文件下载失败");
        } catch (Exception e) {
            log.info("下载图片发生异常");
            e.printStackTrace();
            throw new BusinessException(500, "文件下载失败");
        }
    }
}

注意我这里是将二维码保存到了本地 ./resources/qrcode/ 路径下，然后通过 http://localhost:1000/api-base/qrcode/m1BGhAAj29N9eIeKbyEBvocXXboW1RGc 调用自己的下载接口下载的，大家可以直接就返回生成的二维码文件即可