实现二维码且二维码中加logo图片，工作记录，供大家借鉴

一.准备步骤

　　1.1 pom.xml

    <!-- 二维码 https://mvnrepository.com/artifact/com.google.zxing/core -->
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.3.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.google.zxing/javase -->
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>javase</artifactId>
            <version>3.3.0</version>
        </dependency>

1.2 准备一张logo图片，我的图片是服务器上的：http://xxx.xxx.xxx.xx:xxxx//qrCodeImg/logo.png

 1.3 接口源码

  1 package com.web.kds.hadoop_kafka.Controller;
  2 
  3 import java.awt.BasicStroke;
  4 import java.awt.Color;
  5 import java.awt.Graphics2D;
  6 import java.awt.RenderingHints;
  7 import java.awt.image.BufferedImage;
  8 import java.io.ByteArrayInputStream;
  9 import java.io.ByteArrayOutputStream;
 10 import java.io.File;
 11 import sun.misc.BASE64Decoder;
 12 import java.io.IOException;
 13 import java.io.InputStream;
 14 import java.net.URL;
 15 import java.net.URLConnection;
 16 import java.text.SimpleDateFormat;
 17 import java.util.Date;
 18 import java.util.Hashtable;
 19 import java.util.UUID;
 20 
 21 import javax.imageio.ImageIO;
 22 import javax.servlet.ServletOutputStream;
 23 import javax.servlet.http.HttpServletRequest;
 24 import javax.servlet.http.HttpServletResponse;
 25 
 26 import org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload;
 27 import org.springframework.util.StringUtils;
 28 import org.springframework.web.bind.annotation.PostMapping;
 29 import org.springframework.web.bind.annotation.RequestBody;
 30 import org.springframework.web.bind.annotation.RequestMapping;
 31 import org.springframework.web.bind.annotation.RequestParam;
 32 import org.springframework.web.bind.annotation.ResponseBody;
 33 import org.springframework.web.bind.annotation.RestController;
 34 import org.springframework.web.multipart.MultipartFile;
 35 import org.springframework.web.multipart.MultipartHttpServletRequest;
 36 
 37 import com.google.zxing.BarcodeFormat;
 38 import com.google.zxing.EncodeHintType;
 39 import com.google.zxing.MultiFormatWriter;
 40 import com.google.zxing.WriterException;
 41 import com.google.zxing.client.j2se.MatrixToImageWriter;
 42 import com.google.zxing.common.BitMatrix;
 43 import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 44 
 45 import sun.misc.BASE64Encoder;
 46 
 47 @RestController
 48 @RequestMapping("qrcode")
 49 public class QrCodeController {
 50     private static final int BLACK = 0xFF000000;
 51     private static final int WHITE = 0xFFFFFFFF;
 52     private static final int margin = 0;
 53     private static final int LogoPart = 4;
 54     private static final String logoPath ="http://xxx.xxx.xxx.xx:8081//qrCodeImg/logo.png";
 55 
 56 
 57     @RequestMapping("getfile")
 58     public void getQrCodeFile(HttpServletResponse resp) throws Exception {
 59         ServletOutputStream stream = resp.getOutputStream();;
 60         String content = "www.baidu.com";
 61         int width = 260;
 62         int height = 260;
 63         BitMatrix bitMatrix = setBitMatrix(content, width, height);
 64         
 65         BufferedImage image = toBufferedImage(bitMatrix);
 66         // 加入LOGO水印效果
 67         if (logoPath!=null &&!logoPath.equals("")) {
 68             image = addLogo(image, logoPath);
 69         }
 70         // 可通过输出流输出到页面,也可直接保存到文件
 71         ImageIO.write(image, "png", resp.getOutputStream());
 72     }
 73     /**
 74      * 生成二维码矩阵信息
 75      * @param content 二维码图片内容
 76      * @param width 二维码图片宽度
 77      * @param height 二维码图片高度
 78      */
 79     public static BitMatrix setBitMatrix(String content, int width, int height){
 80         Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
 81         hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); // 指定编码方式,防止中文乱码
 82         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 指定纠错等级
 83         hints.put(EncodeHintType.MARGIN, margin); // 指定二维码四周白色区域大小
 84         BitMatrix bitMatrix = null;
 85         try {
 86             bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, width, height, hints);
 87         } catch (WriterException e) {
 88             e.printStackTrace();
 89         }
 90         return bitMatrix;
 91     }
 92 
 93 
 94 
 95     /**
 96      * 生成二维码图片  去白边
 97      * @param matrix 二维码矩阵信息
 98      */
 99     public static BufferedImage toBufferedImage(BitMatrix matrix) {
100         int width = matrix.getWidth();
101         int height = matrix.getHeight();
102         BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
103         for (int x = 0; x < width; x++) {
104             for (int y = 0; y < height; y++) {
105                 image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
106             }
107         }
108         return image;
109     }
110     /**
111      * 在二维码图片中添加logo图片
112      * @param image 二维码图片
113      * @param logoPath logo图片路径
114      * @throws IOException 
115      */
116     public static BufferedImage addLogo(BufferedImage image, String logoPath) throws IOException{
117         BASE64Decoder base64de = new BASE64Decoder();
118         Graphics2D g = image.createGraphics();
119         //消除文字锯齿
120         g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
121         //消除画图锯齿
122         g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
123 
124         //把Base64编码过的字节数组字符串解码转换成字节数组
125         byte[] b= base64de.decodeBuffer(downloadFile(logoPath));
126         //将字节数组转化为输入流
127         InputStream   is=new ByteArrayInputStream(b);
128         //将图片流写入ImageIO流
129         BufferedImage logoImage = ImageIO.read(is);
130         // 计算logo图片大小,可适应长方形图片,根据较短边生成正方形
131         int width = image.getWidth() < image.getHeight() ? image.getWidth() / LogoPart : image.getHeight() / LogoPart;
132         int height = width;
133         // 计算logo图片放置位置
134         int x = (image.getWidth()-width)/ 2;
135         int y = (image.getHeight()-height)/ 2;
136         int x1 = (image.getWidth()-width-10)/ 2;
137         int y1 = (image.getHeight()-height-10)/ 2;
138         // 边框颜色
139         g.setColor(Color.white);
140         // 画笔粗细
141         g.setStroke(new BasicStroke(5)); // 画笔粗细
142         //画图层,作用是在logo图片周围加点白边，显示更美观
143         g.fillRect(x1, y1, width+10, height+10);
144         //绘制logo边框,
145         g.drawRoundRect(x1, y1, width+10,height+10, 30, 30);
146 
147         // 在二维码图片上绘制logo图片
148         g.drawImage(logoImage, x, y, width, height, null);
149         logoImage.flush();
150         g.dispose();
151         return image;
152     }
153     //将网络图片转base64
154     public static String downloadFile(String urlPath){
155         ByteArrayOutputStream data = new ByteArrayOutputStream();  
156         try {
157             // 打开图片路径
158             URL url = new URL(urlPath);
159             URLConnection connection = url.openConnection();
160             // 通过输入流获取图片数据
161             InputStream in = connection.getInputStream();
162             byte[] by = new byte[1024];
163             // 将内容读取内存中
164             int len = -1;
165             while ((len = in.read(by)) != -1) {
166                 data.write(by, 0, len);
167             }
168             //关闭流
169             in.close();     
170         } catch (IOException e) {
171             e.printStackTrace();
172         }
173         // 返回Base64编码过的字节数组字符串
174         BASE64Encoder encoder = new BASE64Encoder();     
175         return encoder.encode(data.toByteArray());
176     }
177 
178 }

 二.效果图：http://localhost:8080/qrcode/getfile

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原文地址：https://www.cnblogs.com/KdeS/p/11797001.html