//生成QR二维码

import com.google.zxing.EncodeHintType;
import net.glxn.qrgen.core.image.ImageType;
import net.glxn.qrgen.javase.QRCode;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import java.io.*;
import java.util.Base64;

 @Test
    void test() throws IOException {
        //二维码信息
        String url = "path";
        //设置宽度和高度
        int width = 240, height = 240;
        //设置边框值
        int margin = 1;
        //根据设置的参数生成字节输出流
        ByteArrayOutputStream out = QRCode.from(url).withHint(EncodeHintType.MARGIN, margin).to(ImageType.JPG).withSize(width, height).stream();
        //可以简单生成
        //ByteArrayOutputStream out = QRCode.from(url).to(ImageType.PNG).stream();
        //获取字节数组
        byte[] data = out.toByteArray();
        //指定存储位置
        String imagePath = "C:\\Users\\LZW\\Desktop\\new.jpg";
        //判断文件是否存在，如果存在删除
        File file = new File(imagePath);
        if (file.exists()) {
            file.delete();
        }
        //写入文件
        OutputStream oute = new FileOutputStream(new File(imagePath));
        oute.write(data);
        oute.flush();
        oute.close();
        //转base64 注意前缀data:image/jpg;base64,
        String imageBase64 = Base64.getEncoder().encodeToString(data);
        System.out.println(imageBase64);
    }

QRcode二维码依赖

<dependency>
    <groupId>net.glxn.qrgen</groupId>
    <artifactId>javase</artifactId>
    <version>2.0</version>
</dependency>