drawimage（draw图片）

首先，我们需要一个二维码生成库来生成二维码。我建议使用Zxing库，你可以通过以下方式添加到你的项目依赖中：

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.3.0</version>
</dependency>

   
    
    

   <dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.3.0</version>
</dependency>

然后我们可以创建一个服务类来进行图片处理：

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;
import org.springframework.stereotype.Service;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;

@Service
public class ImageService {
    public void drawImageWithQRAndText() throws WriterException, IOException {
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        Map<EncodeHintType, ErrorCorrectionLevel> hints = new HashMap<>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
        BitMatrix bitMatrix = qrCodeWriter.encode("QR Code Content", BarcodeFormat.QR_CODE, 400, 400, hints);

        BufferedImage qrImage = new BufferedImage(400, 400, BufferedImage.TYPE_INT_RGB);
        for (int i = 0; i < 400; i++) {
            for (int j = 0; j < 400; j++) {
                qrImage.setRGB(i, j, (bitMatrix.get(i, j) ? Color.BLACK : Color.WHITE).getRGB());
            }
        }

        Path imagePath = Paths.get("path-to-your-image");
        InputStream is = Files.newInputStream(imagePath);
        BufferedImage sourceImage = ImageIO.read(is);

        Graphics2D g = sourceImage.createGraphics();
        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        g.drawImage(qrImage, (sourceImage.getWidth() - qrImage.getWidth()) / 2, (sourceImage.getHeight() - qrImage.getHeight()) / 2, null);
        g.setColor(Color.BLACK);
        g.setFont(new Font("Arial", Font.BOLD, 30));
        g.drawString("扫一扫", (sourceImage.getWidth() - g.getFontMetrics().stringWidth("扫一扫")) / 2, sourceImage.getHeight() / 2 + qrImage.getHeight() / 2 + 50);
        g.dispose();

        ImageIO.write(sourceImage, "png", Files.newOutputStream(imagePath));
    }
}

这个服务类的drawImageWithQRAndText方法首先创建了一个400×400大小的二维码，然后将它绘制在指定图片的中心位置，接着在二维码下方绘制了“扫一扫”的文字。最后，它将处理后的图片保存回文件。

为了避免文字有锯齿，我们使用了
RenderingHints.KEY_TEXT_ANTIALIASING渲染提示进行抗锯齿处理。