How to Read Or Parse QR Code in Java

阳光穿透心脏的1/2处 2024-02-18 21:53 23阅读 0赞

**摘要**：有个群友在群里问，二维码生成和解析用java怎么做，正好有空，我也写了下，记录一下，有需要的同学可以参考下，这里主要是使用了Google的一个开源包zxing。

**一：导入zxing的依赖，如下：**

<dependency>
                <groupId>com.google.zxing</groupId>
                <artifactId>core</artifactId>
                <version>3.2.1</version>
            </dependency>

**二：ZxingUtils工具类，其中包括生成二维码，解析二维码方法：**

package com.micai.springboot.util;
    
    import java.awt.Color;
    import java.awt.Graphics2D;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.IOException;
    import java.util.EnumMap;
    import java.util.Map;
    
    import javax.imageio.ImageIO;
    
    import com.google.zxing.*;
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.common.HybridBinarizer;
    import com.google.zxing.qrcode.QRCodeReader;
    import com.google.zxing.qrcode.QRCodeWriter;
    import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
    
    /**
     * @Auther: zhaoxinguo
     * @Date: 2018/7/24 15:00
     * @Description: 二维码工具类
     */
    public class ZxingUtils {
    
        /**
         * 生成二维码
         * @param fromUrl
         * @param toUrl
         */
        public static void createQrCode(String fromUrl, String toUrl) {
            String myCodeText = fromUrl;
            String filePath = toUrl;
            int size = 250;
            String fileType = "png";
            File myFile = new File(filePath);
            try {
    
                Map<EncodeHintType, Object> hintMap = new EnumMap<EncodeHintType, Object>(EncodeHintType.class);
                hintMap.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    
                // Now with zxing version 3.2.1 you could change border size (white border size to just 1)
                hintMap.put(EncodeHintType.MARGIN, 1); /* default = 4 */
                hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
    
                QRCodeWriter qrCodeWriter = new QRCodeWriter();
                BitMatrix byteMatrix = qrCodeWriter.encode(myCodeText, BarcodeFormat.QR_CODE, size, size, hintMap);
                int CrunchifyWidth = byteMatrix.getWidth();
                BufferedImage image = new BufferedImage(CrunchifyWidth, CrunchifyWidth, BufferedImage.TYPE_INT_RGB);
                image.createGraphics();
    
                Graphics2D graphics = (Graphics2D) image.getGraphics();
                graphics.setColor(Color.WHITE);
                graphics.fillRect(0, 0, CrunchifyWidth, CrunchifyWidth);
                graphics.setColor(Color.BLACK);
    
                for (int i = 0; i < CrunchifyWidth; i++) {
                    for (int j = 0; j < CrunchifyWidth; j++) {
                        if (byteMatrix.get(i, j)) {
                            graphics.fillRect(i, j, 1, 1);
                        }
                    }
                }
                ImageIO.write(image, fileType, myFile);
            } catch (WriterException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            System.out.println("\n\nYou have successfully created QR Code.");
        }
    
        /**
         * 解析二维码
         * @param filePath
         * @return
         */
        public static String readQRCode(String filePath) {
    
            File file = new File(filePath);
            BufferedImage image = null;
            BinaryBitmap bitmap = null;
            Result result = null;
    
            try {
                image = ImageIO.read(file);
                int[] pixels = image.getRGB(0, 0, image.getWidth(), image.getHeight(), null, 0, image.getWidth());
                RGBLuminanceSource source = new RGBLuminanceSource(image.getWidth(), image.getHeight(), pixels);
                bitmap = new BinaryBitmap(new HybridBinarizer(source));
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    
            if (bitmap == null)
                return null;
    
            QRCodeReader reader = new QRCodeReader();
            try {
                result = reader.decode(bitmap);
                return result.getText();
            } catch (NotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ChecksumException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (FormatException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    
            return null;
        }
    
        public static void main(String [] args) {
            String myCodeText = "https://blog.csdn.net/sxdtzhaoxinguo/";
            String filePath = "D://CrunchifyQR.png";
    //        createQrCode(myCodeText, filePath);
            String readQRCode = readQRCode(filePath);
            System.out.println(readQRCode);
        }
    }

**三：运行结果：**

1.生成二维码：

![70][]

2.解析二维码：

![70 1][]

这样就实现了java生成二维码和解析二维码，这里只是简单的实现，zxing里面包含了好多api，有兴趣的同学可以自己研究，这里放个zxing的api地址：[https://zxing.github.io/zxing/apidocs/index.html][https_zxing.github.io_zxing_apidocs_index.html]

[70]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/45f4aadf25824dc583934bd354ffecec.png
[70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/6dd656390a794a5c9363d17db7b89117.png
[https_zxing.github.io_zxing_apidocs_index.html]: https://zxing.github.io/zxing/apidocs/index.html