springboot扫码签到

您可以使用Zxing库来生成二维码，然后使用微信或支付宝扫描二维码进行签到。以下是一个简单的示例代码：

1. 添加依赖

在pom.xml文件中添加以下依赖：

<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>

2. 生成二维码

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;

public class QRCodeGenerator {
    private static final String QR_CODE_IMAGE_PATH = "./MyQRCode.png";

    private static void generateQRCodeImage(String text, int width, int height, String filePath)
            throws WriterException, IOException {
        Map<EncodeHintType, Object> hintMap = new HashMap<EncodeHintType, Object>();
        hintMap.put(EncodeHintType.CHARACTER_SET, "UTF-8");

        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height, hintMap);
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                int grayValue = (bitMatrix.get(x, y) ? 0 : 1) & 0xff;
                image.setRGB(x, y, (grayValue == 0 ? 0 : 0xFFFFFF));
            }
        }

        File qrFile = new File(filePath);
        ImageIO.write(image, "png", qrFile);
    }

    public static void main(String[] args) {
        try {
            generateQRCodeImage("https://www.baidu.com", 350, 350, QR_CODE_IMAGE_PATH);
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

这个示例代码将生成一个包含百度网址的二维码，并将其保存在MyQRCode.png文件中。