Java中生成二维码转为base64存入MySQL数据库中

1.引入架包

<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.Java实体类中增加字段

    @ApiModelProperty(value = "二维码")
    private String qrCode;

3.MySQL表中增加字段，类型为blob

alter table `tableName` 
add column `qr_code` blob null comment '二维码' ;

4.生成工具类

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
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.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Base64;
import java.util.Hashtable;

public class QRCodeUtil {
    public static String generateQRCodeToBase64(String text, int width, int height) throws WriterException, IOException {
        com.google.zxing.Writer writer = new QRCodeWriter();
        Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

        BitMatrix bitMatrix = writer.encode(text, BarcodeFormat.QR_CODE, width, height, hints);
        BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(image, "png", baos);
        baos.flush();
        byte[] imageBytes = baos.toByteArray();
        baos.close();

        return Base64.getEncoder().encodeToString(imageBytes);
    }

    // 将Base64字符串解码为二维码图片的方法（可选）
    public static BufferedImage decodeBase64ToQRCodeImage(String base64String) throws IOException {
        byte[] imageBytes = Base64.getDecoder().decode(base64String);
        return ImageIO.read(new ByteArrayInputStream(imageBytes));
    }

    /**
     * https://blog.csdn.net/qq_60542647/article/details/138083115   二维码转base64
     * https://www.lddgo.net/convert/base64-to-image   base64 在线Base64转图片
     * @param args
     */
    public static void main(String[] args) {
        try {
            String base64 = generateQRCodeToBase64("www.baidu.com", 200, 200);
            System.out.println(base64);
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}