java生成二维码

<!-- pom引入jar包 -->

<!-- 二维码生成 -->
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.1.0</version>
</dependency>

package com.zhx.util;


import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.util.Hashtable;
//二维码生成工具类
public class ErweimaUtil {
    
    private static final String CHARSET = "utf-8";  
    private static final String FORMAT_NAME = "JPG";  
    // 二维码尺寸  
    private static final int QRCODE_SIZE = 300;  
    // LOGO宽度  
    private static final int WIDTH = 60;  
    // LOGO高度  
    private static final int HEIGHT = 60; 
    
    public static void main(String[] args) {
        try {
            BufferedImage img = createImage("该公司没有信用名片",null,true);
            
            String b64 = bfimgToBase64(img);
            System.out.println("data:image/png;base64,"+b64);
            
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
    
    //把图片存入字符流
    public static BufferedImage createImage(String content,String imgPath,boolean needCompress) throws Exception {
        Hashtable hints = new Hashtable();  
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);  
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);  
        hints.put(EncodeHintType.MARGIN, 1);  
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content,  
                BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);  
        int width = bitMatrix.getWidth();  
        int height = bitMatrix.getHeight();  
        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);  
            }  
        }
        if(imgPath == null || "".equals(imgPath)){
            return image;
        }
        ErweimaUtil.insertImage(image,imgPath,needCompress);
        
        return image;  
    } 
    //把图片字符流转成base64
    public static String bfimgToBase64(BufferedImage bufferedImage){
        String imgBase64 = null;
        try {
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            ImageIO.write(bufferedImage, "jpeg", outputStream);
            BASE64Encoder encoder = new BASE64Encoder();
            imgBase64 = encoder.encode(outputStream.toByteArray()).trim().replaceAll("\\s", "").replaceAll("\r", "").replaceAll("\n", "");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return imgBase64;
    }

    public static void insertImage(BufferedImage source, String imgPath,
                                    boolean needCompress) throws Exception {
        File file = new File(imgPath);
        if (!file.exists()) {
            System.err.println(""+imgPath+"   该文件不存在！");
            return;
        }
        Image src = ImageIO.read(new File(imgPath));
        int width = src.getWidth(null);
        int height = src.getHeight(null);
        if (needCompress) { // 压缩LOGO
            if (width > WIDTH) {
                width = WIDTH;
            }
            if (height > HEIGHT) {
                height = HEIGHT;
            }
            Image image = src.getScaledInstance(width, height,
                    Image.SCALE_SMOOTH);
            BufferedImage tag = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics g = tag.getGraphics();
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图
            g.dispose();
            src = image;
        }
        // 插入LOGO
        Graphics2D graph = source.createGraphics();
        int x = (QRCODE_SIZE - width) / 2;
        int y = (QRCODE_SIZE - height) / 2;
        graph.drawImage(src, x, y, width, height, null);
        Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    }
    
}
 

//controll调用
 @RequestMapping("/toGenerateQrCode")
    public ModelAndView toGenerateQrCode(String sellers_id, String goods_id, ModelAndView modelAndView) throws Exception {
        BufferedImage image = null;
        if("".equals(goods_id) || goods_id == null){
            image = ErweimaUtil.createImage("123456","",true);
        }else {
            image = ErweimaUtil.createImage("789","",true);
        }
        String b64 = ErweimaUtil.bfimgToBase64(image);//转成base64
        String qrcode = "data:image/png;base64," + b64;//图片url
        modelAndView.addObject("qrcode",qrcode);
        modelAndView.addObject("goods_id",goods_id);
        modelAndView.addObject("sellers_id",sellers_id);
        modelAndView.setViewName("/resellerGoods/goodsQrCode");
        return modelAndView;
    }

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8"/>
    <title>二维码图片</title>
    <div th:replace="head"></div>
</head>
<body>
<div id="qrCode">
    <image th:src="${qrcode}"></image>
</div>//二维码地址
<a th:href="${qrcode}" download="二维码.jpg">下载二维码</a>
</body>
</html>