写一个java生成二维码的代码

当然可以！以下是Java生成二维码的示例代码：

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

public class QrCodeGenerator {
    public static void main(String[] args) {
        String text = "https://www.example.com";
        int width = 350;
        int height = 350;
        String format = "png";
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.MARGIN, 1);
        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            for (int x = 0; x < width; x++) {
                for (int y = 0; y < height; y++) {
                    image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
                }
            }
            File qrFile = new File("qrcode.png");
            ImageIO.write(image, format, qrFile);
            System.out.println("二维码生成成功！");
        } catch (WriterException | IOException e) {
            e.printStackTrace();
        }
    }
}

这段代码使用Google的ZXing库生成二维码。你只需要将`text`变量替换为你要生成二维码的内容即可。