更详细的二维码生成和解析

拼搏现实的明天。 2024-04-18 16:24 1阅读 0赞

1,依赖

<dependency>
        <groupId>com.google.zxing</groupId>
        <artifactId>core</artifactId>
        <version>3.3.0</version>
    </dependency>

2,帮助类

package cn.hyt.hyt_zhdj_cs.utils;
    
    import java.awt.Graphics2D;
    import java.awt.geom.AffineTransform;
    import java.awt.image.BufferedImage;
    import com.google.zxing.LuminanceSource;
    
    public class BufferedImageLuminanceSource extends LuminanceSource {
        private final BufferedImage image;
        private final int left;
        private final int top;
    
        public BufferedImageLuminanceSource(BufferedImage image) {
            this(image, 0, 0, image.getWidth(), image.getHeight());
        }
    
        public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
            super(width, height);
    
            int sourceWidth = image.getWidth();
            int sourceHeight = image.getHeight();
            if (left + width > sourceWidth || top + height > sourceHeight) {
                throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
            }
    
            for (int y = top; y < top + height; y++) {
                for (int x = left; x < left + width; x++) {
                    if ((image.getRGB(x, y) & 0xFF000000) == 0) {
                        image.setRGB(x, y, 0xFFFFFFFF); // = white
                    }
                }
            }
    
            this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
            this.image.getGraphics().drawImage(image, 0, 0, null);
            this.left = left;
            this.top = top;
        }
    
        public byte[] getRow(int y, byte[] row) {
            if (y < 0 || y >= getHeight()) {
                throw new IllegalArgumentException("Requested row is outside the image: " + y);
            }
            int width = getWidth();
            if (row == null || row.length < width) {
                row = new byte[width];
            }
            image.getRaster().getDataElements(left, top + y, width, 1, row);
            return row;
        }
    
        public byte[] getMatrix() {
            int width = getWidth();
            int height = getHeight();
            int area = width * height;
            byte[] matrix = new byte[area];
            image.getRaster().getDataElements(left, top, width, height, matrix);
            return matrix;
        }
    
        public boolean isCropSupported() {
            return true;
        }
    
        public LuminanceSource crop(int left, int top, int width, int height) {
            return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
        }
    
        public boolean isRotateSupported() {
            return true;
        }
    
        public LuminanceSource rotateCounterClockwise() {
            int sourceWidth = image.getWidth();
            int sourceHeight = image.getHeight();
            AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
            BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
            Graphics2D g = rotatedImage.createGraphics();
            g.drawImage(image, transform, null);
            g.dispose();
            int width = getWidth();
            return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
        }
    
    }

3,工具类

package cn.hyt.hyt_zhdj_cs.utils;
    
    import java.awt.BasicStroke;
    import java.awt.Graphics;
    import java.awt.Graphics2D;
    import java.awt.Image;
    import java.awt.Shape;
    import java.awt.geom.RoundRectangle2D;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.io.OutputStream;
    import java.util.Hashtable;
    import javax.imageio.ImageIO;
    import com.google.zxing.BarcodeFormat;
    import com.google.zxing.BinaryBitmap;
    import com.google.zxing.DecodeHintType;
    import com.google.zxing.EncodeHintType;
    import com.google.zxing.MultiFormatReader;
    import com.google.zxing.MultiFormatWriter;
    import com.google.zxing.Result;
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.common.HybridBinarizer;
    import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
    
    public class QRCodeUtil {
        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;
    
        private 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;
            }
            // 插入图片
            QRCodeUtil.insertImage(image, imgPath, needCompress);
            return image;
        }
    
        private 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();
        }
    
        public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
            BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
            mkdirs(destPath);
            // String file = new Random().nextInt(99999999)+".jpg";
            // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
            ImageIO.write(image, FORMAT_NAME, new File(destPath));
        }
    
        public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
            BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
            return image;
        }
    
        public static void mkdirs(String destPath) {
            File file = new File(destPath);
            // 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
            if (!file.exists() && !file.isDirectory()) {
                file.mkdirs();
            }
        }
    
        public static void encode(String content, String imgPath, String destPath) throws Exception {
            QRCodeUtil.encode(content, imgPath, destPath, false);
        }
        // 被注释的方法
        /*
         * public static void encode(String content, String destPath, boolean
         * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
         * needCompress); }
         */
    
        public static void encode(String content, String destPath) throws Exception {
            QRCodeUtil.encode(content, null, destPath, false);
        }
    
        public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
                throws Exception {
            BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
            ImageIO.write(image, FORMAT_NAME, output);
        }
    
        public static void encode(String content, OutputStream output) throws Exception {
            QRCodeUtil.encode(content, null, output, false);
        }
    
        public static String decode(File file) throws Exception {
            BufferedImage image;
            image = ImageIO.read(file);
            if (image == null) {
                return null;
            }
            BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
            Result result;
            Hashtable hints = new Hashtable();
            hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
            result = new MultiFormatReader().decode(bitmap, hints);
            String resultStr = result.getText();
            return resultStr;
        }
    
        public static String decode(String path) throws Exception {
            return QRCodeUtil.decode(new File(path));
        }
    
    }

4,应用

@ApiOperation(value = "二维码")
        @PostMapping("qrcode")
        public AppResponseJson qrcode() throws Exception {
            // 存放在二维码中的内容
    		String text = "我是小铭";
    		// 嵌入二维码的图片路径
    		String imgPath = "G:/qrCode/dog.jpg";
    		// 生成的二维码的路径及名称
    		String destPath = "G:/qrCode/qrcode/jam.jpg";
    		//生成二维码
    		QRCodeUtil.encode(text, imgPath, destPath, true);
    		// 解析二维码
    		String str = QRCodeUtil.decode(destPath);
    		// 打印出解析出的内容
    		System.out.println(str);
            return AppResponseJson.successRequest("成功");
        }

生成二维码方法：

QRCodeUtil.encode(text, imgPath, destPath, true);

text：编码到二维码中的内容，这里是“我是小铭”

imgPath：要嵌入二维码的图片路径，如果不写或者为null则生成一个没有嵌入图片的纯净的二维码

destPath：生成的二维码的存放路径

true：表示将嵌入二维码的图片进行压缩，如果为“false”则表示不压缩。

解析二维码方法：

QRCodeUtil.decode(destPath);

destPath：将要解析的二维码的存放路径

该方法返回值为String类型，即返回解析出的文字或者数字等。

**如果你想让别人扫描后跳转一个页面的话，直接在编码的方法里，将编码内容改为一个地址就可以了，这样别人扫描二维码后会自动跳转.二维码存的信息越多，二维码图片也就越复杂，容错率也就越低，识别率也越低，并且二维码能存的内容大小也是有限的（大概500个汉字左右）。**