Java生成二維碼

Maven依賴

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.5.0</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.5.0</version>
</dependency>

生成二維碼

public static void generateQRCodeImage(String text, int width, int height, String filePath, HashMap hints)
    throws WriterException, IOException {
    QRCodeWriter qrCodeWriter = new QRCodeWriter();
    BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height, hints);
    Path path = FileSystems.getDefault().getPath(filePath);
    MatrixToImageWriter.writeToPath(bitMatrix, "PNG", path);
}

解析二維碼

public static void parseQRCodeImage(String filePath,HashMap hints)
    throws NotFoundException, IOException, ChecksumException, FormatException {
    QRCodeReader qrCodeReader = new QRCodeReader();
    File file = new File(filePath);
    BufferedImage bufferedImage = ImageIO.read(file);
    LuminanceSource luminanceSource = new BufferedImageLuminanceSource(bufferedImage);
    Binarizer binarizer = new HybridBinarizer(luminanceSource);
    BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
    Result result = qrCodeReader.decode(binaryBitmap);
    System.out.println(result.getText());
}

Main方法

public static void main(String[] args) {
    int width = 400;
    int height = 400;
    String format = "png";
    String content = "https://www.baidu.com";
    String filePath = "E:/dev/test.png";

    HashMap<EncodeHintType, Object> hints = new HashMap<>();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    //L 水平 7%的字碼可被修正
    //M 水平 15%的字碼可被修正
    //Q 水平 25%的字碼可被修正
    //H 水平 30%的字碼可被修正
    hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
    hints.put(EncodeHintType.MARGIN, 2);

    try {
        generateQRCodeImage(content, width, height, filePath, hints);
        parseQRCodeImage(filePath,hints);
    } catch (WriterException e) {
        throw new RuntimeException(e);
    } catch (IOException e) {
        throw new RuntimeException(e);
    } catch (ChecksumException e) {
        throw new RuntimeException(e);
    } catch (NotFoundException e) {
        throw new RuntimeException(e);
    } catch (FormatException e) {
        throw new RuntimeException(e);
    }
}

Controller方法

@Controller
@RequestMapping("qr")
public class QrController {
    @RequestMapping
    public void createQrCode(HttpServletResponse response) throws WriterException, IOException {
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
        hints.put(EncodeHintType.MARGIN, 2);
        BitMatrix bitMatrix = new QRCodeWriter().encode("content", BarcodeFormat.QR_CODE, 200, 200, hints);
        MatrixToImageWriter.writeToStream(bitMatrix, "png", response.getOutputStream());
    }
}