简述：最近有接到一个需求，生成二维码，然后打包成zip ，最后下载，且不用文件服务器！
1、spring boot 搭建项目我就不多写了，网上一大堆
2、maven 引入jar包

 <dependency>
     <groupId>com.google.zxing</groupId>
     <artifactId>core</artifactId>
     <version>3.4.0</version>
</dependency>

3、controller 编写

/**
 * @author lucksheep
 */
@Controller
@RequestMapping("/download")
public class DownloadController {

   /**
     * 自定义生成N张二维码，且打包下载
     * @param request
     * @param response
     * @param number
     * @throws IOException
     * @throws WriterException
     */
    @GetMapping("/qrcode/zip/{number}")
    public void downloadZip(HttpServletRequest request, HttpServletResponse response,@PathVariable Integer number) throws IOException, WriterException {
        String zipName=new String("二维码".getBytes(),"ISO-8859-1") + ".zip";
        response.setContentType("application/zip");
        response.setHeader("Content-disposition","attachment; filename=" +zipName );
        OutputStream outputStream = response.getOutputStream();
        ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream);
        for (int i=0;i<number;i++) {
            String url = "https://www.baidu.com/";
            BufferedImage buffImg = QRcodeUntil.getBufferedImage(null, url);
            ZipEntry entry = new ZipEntry("二维码"+i+".png");
            zipOutputStream.putNextEntry(entry);
            ImageIO.write(buffImg, "png", zipOutputStream);
        }
        zipOutputStream.flush();
        zipOutputStream.close();
        outputStream.flush();
        outputStream.close();
    }

    @GetMapping("/qrcode")
    public void downloadQrcode(HttpServletRequest request, HttpServletResponse response) throws IOException, WriterException {
        String imgName=new String("我是谁".getBytes(),"ISO-8859-1") + ".png";
        response.setContentType("application/force-download");
        response.setHeader("Content-disposition","attachment; filename=" +imgName );
        OutputStream outputStream = response.getOutputStream();
        String url = "https://www.baidu.com/";
        BufferedImage buffImg = QRcodeUntil.getBufferedImage(null, url);
        ImageIO.write(buffImg, "png", outputStream);
        outputStream.flush();
        outputStream.close();
    }
}

4、二维码生成帮助类 QRcodeUntil .java

package com.mvc.smus.common;

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;
import org.springframework.util.StringUtils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

/**
 * 画制定logo和制定描述的二维码
 * @author zy
 */
public class QRcodeUntil {

    /**
     * 默认是黑色
     */
    private static final int QRCOLOR = 0xFF000000;
    /**
     * 背景颜色
     */
    private static final int BGWHITE = 0xFFFFFFFF;
    /**
     * 二维码宽
     */
    private static final int WIDTH = 400;
    /**
     * 二维码高
     */
    private static final int HEIGHT = 400;

    /**
     * 用于设置QR二维码参数
     */
    public static Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>() {
        private static final long serialVersionUID = 1L;
        {
            // 设置QR二维码的纠错级别（H为最高级别）具体级别信息
            put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            // 设置编码方式
            put(EncodeHintType.CHARACTER_SET, "utf-8");
            put(EncodeHintType.MARGIN, 0);
        }
    };

    public static void main(String[] args) {
        HttpURLConnection httpUrl = null;
        try {
            String imgUrl="http://img2.imgtn.bdimg.com/it/u=2874714129,2818353273&fm=26&gp=0.jpg";
            URL url = new URL(imgUrl);
            httpUrl = (HttpURLConnection) url.openConnection();
            httpUrl.connect();
            InputStream in=httpUrl.getInputStream();
            BufferedImage img=ImageIO.read(in);
            File QrCodeFile = new File("F:/down/textsss.png");
            ImageIO.write(img, "png", QrCodeFile);
        } catch (IOException e) {
        } catch (ClassCastException e) {
        } finally {
            try {
                httpUrl.disconnect();
            } catch (NullPointerException e) {
            }
        }
    }

    /**
     * 生成带logo的二维码图片
     * @param logoFile logo图片地址
     * @param qrUrl
     */
    public static BufferedImage getBufferedImage(File logoFile, String qrUrl) {
        try {
            MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
            // 参数顺序分别为：编码内容，编码类型，生成图片宽度，生成图片高度，设置参数
            BitMatrix bm = multiFormatWriter.encode(qrUrl, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, hints);
            BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
            // 开始利用二维码数据创建Bitmap图片，分别设为黑（0xFFFFFFFF）白（0xFF000000）两色
            for (int x = 0; x < WIDTH; x++) {
                for (int y = 0; y < HEIGHT; y++) {
                    image.setRGB(x, y, bm.get(x, y) ? QRCOLOR : BGWHITE);
                }
            }
            int width = image.getWidth();
            int height = image.getHeight();
            if (Objects.nonNull(logoFile) && logoFile.exists()) {
                // 读取Logo图片
                BufferedImage logo = ImageIO.read(logoFile);
                logo=setRadius(logo,width / 2);
                // 构建绘图对象
                Graphics2D g = image.createGraphics();
                // 开始绘制logo图片
                g.drawImage(logo, width * 2 / 5, height * 2 / 5, width * 2 / 10, height * 2 / 10, null);
                g.dispose();
                logo.flush();
            }
            image.flush();
            return image;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;


    }

    /**
     * 图片设置圆角
     * @param image 图片流
     * @return radius 半径
     * @throws IOException
     */
    public static BufferedImage setRadius(BufferedImage image,int radius){
        int w = image.getWidth();
        int h = image.getHeight();
        BufferedImage output = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2 = output.createGraphics();
        g2.setComposite(AlphaComposite.Src);
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setColor(Color.WHITE);
        g2.fill(new RoundRectangle2D.Float(0, 0, w, h, radius, radius));
        g2.setComposite(AlphaComposite.SrcAtop);
        g2.drawImage(image, 0, 0, null);
        g2.dispose();
        return output;
    }

    /**
     * 设置图片文本
     * @param image
     * @param height
     * @param note
     * @return
     */
    public static BufferedImage setImgText(BufferedImage image,int height,String note){
        // 自定义文本描述
        if (!StringUtils.isEmpty(note)) {
            // 新的图片，把带logo的二维码下面加上文字
            BufferedImage outImage = new BufferedImage(400, 445, BufferedImage.TYPE_4BYTE_ABGR);
            Graphics2D outg = outImage.createGraphics();
            // 画二维码到新的面板
            outg.drawImage(image, 0, 0, image.getWidth(), image.getHeight(), null);
            // 画文字到新的面板
            outg.setColor(Color.BLACK);
            // 字体、字型、字号
            outg.setFont(new Font("宋体", Font.BOLD, 20));
            int strWidth = outg.getFontMetrics().stringWidth(note);
            if (strWidth > 399) {
                // 长度过长就换行
                String note1 = note.substring(0, note.length() / 2);
                String note2 = note.substring(note.length() / 2, note.length());
                int strWidth1 = outg.getFontMetrics().stringWidth(note1);
                int strWidth2 = outg.getFontMetrics().stringWidth(note2);
                outg.drawString(note1, 200 - strWidth1 / 2, height + (outImage.getHeight() - height) / 2 + 12);
                BufferedImage outImage2 = new BufferedImage(400, 485, BufferedImage.TYPE_4BYTE_ABGR);
                Graphics2D outg2 = outImage2.createGraphics();
                outg2.drawImage(outImage, 0, 0, outImage.getWidth(), outImage.getHeight(), null);
                outg2.setColor(Color.BLACK);
                // 字体、字型、字号
                outg2.setFont(new Font("宋体", Font.BOLD, 30));
                outg2.drawString(note2, 200 - strWidth2 / 2,outImage.getHeight() + (outImage2.getHeight() - outImage.getHeight()) / 2 + 5);
                outg2.dispose();
                outImage2.flush();
                outImage = outImage2;
            } else {
                // 画文字
                outg.drawString(note, 200 - strWidth / 2, height + (outImage.getHeight() - height) / 2 + 12);
            }
            outg.dispose();
            outImage.flush();
            image = outImage;
        }
        return image;
    }

}

注释：如果要在二维码图片中显示文字，则加入下面的方法调用