com.google.zxing生成二维码

您可以使用com.google.zxing库生成二维码。下面是一个使用Java代码生成二维码的示例：

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
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.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class QRCodeGenerator {

    private static final int QR_CODE_SIZE = 300;

    public static void generateQRCode(String text, String filePath) throws WriterException, IOException {
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);

        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, QR_CODE_SIZE, QR_CODE_SIZE, hints);

        BufferedImage qrImage = new BufferedImage(QR_CODE_SIZE, QR_CODE_SIZE, BufferedImage.TYPE_INT_RGB);
        qrImage.createGraphics();

        Graphics2D graphics = (Graphics2D) qrImage.getGraphics();
        graphics.setColor(Color.WHITE);
        graphics.fillRect(0, 0, QR_CODE_SIZE, QR_CODE_SIZE);
        graphics.setColor(Color.BLACK);

        for (int i = 0; i < QR_CODE_SIZE; i++) {
            for (int j = 0; j < QR_CODE_SIZE; j++) {
                if (bitMatrix.get(i, j)) {
                    graphics.fillRect(i, j, 1, 1);
                }
            }
        }

        ImageIO.write(qrImage, "png", new File(filePath));
    }

    public static void main(String[] args) {
        String text = "https://www.google.com";
        String filePath = "qrcode.png";