Java 使用 ZXing 生成带底部文字的二维码

要生成带有底部文字的二维码，可以使用 zxing 库的 Java API。下面是一个示例代码：

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
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;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeGenerator {

    public static void main(String[] args) {
        String text = 'https://example.com';
        String bottomText = 'Scan QR code for more information';
        int width = 300;
        int height = 300;
        String format = 'png';
        String filePath = 'qrcode_with_text.png';

        // Set QR code parameters
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix;
        try {
            bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height);
        } catch (WriterException e) {
            e.printStackTrace();
            return;
        }

        // Create BufferedImage object to draw QR code and text
        BufferedImage image = new BufferedImage(width, height + 30, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics2D = (Graphics2D) image.getGraphics();
        graphics2D.setColor(Color.WHITE);
        graphics2D.fillRect(0, 0, width, height + 30);
        graphics2D.setColor(Color.BLACK);

        // Draw QR code
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                if (bitMatrix.get(x, y)) {
                    graphics2D.fillRect(x, y, 1, 1);
                }
            }
        }

        // Draw bottom text
        graphics2D.setFont(new Font('Arial', Font.PLAIN, 12));
        int textWidth = graphics2D.getFontMetrics().stringWidth(bottomText);
        int textHeight = graphics2D.getFontMetrics().getHeight();
        int textX = (width - textWidth) / 2;
        int textY = height + (30 - textHeight) / 2;
        graphics2D.drawString(bottomText, textX, textY);

        // Save QR code image with bottom text
        try {
            ImageIO.write(image, format, new File(filePath));
            System.out.println('QR code with bottom text generated successfully.');
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请确保你已经将 zxing 库添加到你的 Java 项目中。运行上面的代码后，将生成一个名为 "qrcode_with_text.png" 的带有底部文字的二维码图片。