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更详细的二维码生成和解析

 勃士159131 2022-10-29 发布于广东

1,依赖

  1. <dependency>
  2.     <groupId>com.google.zxing</groupId>
  3.     <artifactId>core</artifactId>
  4.     <version>3.3.0</version>
  5. </dependency>

2,帮助类

  1. package cn.hyt.hyt_zhdj_cs.utils;
  3. import java.awt.Graphics2D;
  4. import java.awt.geom.AffineTransform;
  5. import java.awt.image.BufferedImage;
  6. import com.google.zxing.LuminanceSource;
  8. public class BufferedImageLuminanceSource extends LuminanceSource {
  9.     private final BufferedImage image;
  10.     private final int left;
  11.     private final int top;
  13.     public BufferedImageLuminanceSource(BufferedImage image) {
  14.         this(image, 0, 0, image.getWidth(), image.getHeight());
  15.     }
  17.     public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
  18.         super(width, height);
  20.         int sourceWidth = image.getWidth();
  21.         int sourceHeight = image.getHeight();
  22.         if (left + width > sourceWidth || top + height > sourceHeight) {
  23.             throw new IllegalArgumentException('Crop rectangle does not fit within image data.');
  24.         }
  26.         for (int y = top; y < top + height; y++) {
  27.             for (int x = left; x < left + width; x++) {
  28.                 if ((image.getRGB(x, y) & 0xFF000000) == 0) {
  29.                     image.setRGB(x, y, 0xFFFFFFFF); // = white
  30.                 }
  31.             }
  32.         }
  34.         this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
  35.         this.image.getGraphics().drawImage(image, 0, 0, null);
  36.         this.left = left;
  37.         this.top = top;
  38.     }
  40.     public byte[] getRow(int y, byte[] row) {
  41.         if (y < 0 || y >= getHeight()) {
  42.             throw new IllegalArgumentException('Requested row is outside the image: ' + y);
  43.         }
  44.         int width = getWidth();
  45.         if (row == null || row.length < width) {
  46.             row = new byte[width];
  47.         }
  48.         image.getRaster().getDataElements(left, top + y, width, 1, row);
  49.         return row;
  50.     }
  52.     public byte[] getMatrix() {
  53.         int width = getWidth();
  54.         int height = getHeight();
  55.         int area = width * height;
  56.         byte[] matrix = new byte[area];
  57.         image.getRaster().getDataElements(left, top, width, height, matrix);
  58.         return matrix;
  59.     }
  61.     public boolean isCropSupported() {
  62.         return true;
  63.     }
  65.     public LuminanceSource crop(int left, int top, int width, int height) {
  66.         return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
  67.     }
  69.     public boolean isRotateSupported() {
  70.         return true;
  71.     }
  73.     public LuminanceSource rotateCounterClockwise() {
  74.         int sourceWidth = image.getWidth();
  75.         int sourceHeight = image.getHeight();
  76.         AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
  77.         BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
  78.         Graphics2D g = rotatedImage.createGraphics();
  79.         g.drawImage(image, transform, null);
  80.         g.dispose();
  81.         int width = getWidth();
  82.         return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
  83.     }
  85. }

3,工具类

  1. package cn.hyt.hyt_zhdj_cs.utils;
  3. import java.awt.BasicStroke;
  4. import java.awt.Graphics;
  5. import java.awt.Graphics2D;
  6. import java.awt.Image;
  7. import java.awt.Shape;
  8. import java.awt.geom.RoundRectangle2D;
  9. import java.awt.image.BufferedImage;
  10. import java.io.File;
  11. import java.io.OutputStream;
  12. import java.util.Hashtable;
  13. import javax.imageio.ImageIO;
  14. import com.google.zxing.BarcodeFormat;
  15. import com.google.zxing.BinaryBitmap;
  16. import com.google.zxing.DecodeHintType;
  17. import com.google.zxing.EncodeHintType;
  18. import com.google.zxing.MultiFormatReader;
  19. import com.google.zxing.MultiFormatWriter;
  20. import com.google.zxing.Result;
  21. import com.google.zxing.common.BitMatrix;
  22. import com.google.zxing.common.HybridBinarizer;
  23. import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
  25. public class QRCodeUtil {
  26.     private static final String CHARSET = 'utf-8';
  27.     private static final String FORMAT_NAME = 'JPG';
  28.     // 二维码尺寸
  29.     private static final int QRCODE_SIZE = 300;
  30.     // LOGO宽度
  31.     private static final int WIDTH = 60;
  32.     // LOGO高度
  33.     private static final int HEIGHT = 60;
  35.     private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
  36.         Hashtable hints = new Hashtable();
  37.         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
  38.         hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
  39.         hints.put(EncodeHintType.MARGIN, 1);
  40.         BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,
  41.                 hints);
  42.         int width = bitMatrix.getWidth();
  43.         int height = bitMatrix.getHeight();
  44.         BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
  45.         for (int x = 0; x < width; x++) {
  46.             for (int y = 0; y < height; y++) {
  47.                 image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
  48.             }
  49.         }
  50.         if (imgPath == null || ''.equals(imgPath)) {
  51.             return image;
  52.         }
  53.         // 插入图片
  54.         QRCodeUtil.insertImage(image, imgPath, needCompress);
  55.         return image;
  56.     }
  58.     private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception {
  59.         File file = new File(imgPath);
  60.         if (!file.exists()) {
  61.             System.err.println('' + imgPath + '   该文件不存在！');
  62.             return;
  63.         }
  64.         Image src = ImageIO.read(new File(imgPath));
  65.         int width = src.getWidth(null);
  66.         int height = src.getHeight(null);
  67.         if (needCompress) { // 压缩LOGO
  68.             if (width > WIDTH) {
  69.                 width = WIDTH;
  70.             }
  71.             if (height > HEIGHT) {
  72.                 height = HEIGHT;
  73.             }
  74.             Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
  75.             BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
  76.             Graphics g = tag.getGraphics();
  77.             g.drawImage(image, 0, 0, null); // 绘制缩小后的图
  78.             g.dispose();
  79.             src = image;
  80.         }
  81.         // 插入LOGO
  82.         Graphics2D graph = source.createGraphics();
  83.         int x = (QRCODE_SIZE - width) / 2;
  84.         int y = (QRCODE_SIZE - height) / 2;
  85.         graph.drawImage(src, x, y, width, height, null);
  86.         Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
  87.         graph.setStroke(new BasicStroke(3f));
  88.         graph.draw(shape);
  89.         graph.dispose();
  90.     }
  92.     public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
  93.         BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
  94.         mkdirs(destPath);
  95.         // String file = new Random().nextInt(99999999)+'.jpg';
  96.         // ImageIO.write(image, FORMAT_NAME, new File(destPath+'/'+file));
  97.         ImageIO.write(image, FORMAT_NAME, new File(destPath));
  98.     }
  100.     public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
  101.         BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
  102.         return image;
  103.     }
  105.     public static void mkdirs(String destPath) {
  106.         File file = new File(destPath);
  107.         // 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)
  108.         if (!file.exists() && !file.isDirectory()) {
  109.             file.mkdirs();
  110.         }
  111.     }
  113.     public static void encode(String content, String imgPath, String destPath) throws Exception {
  114.         QRCodeUtil.encode(content, imgPath, destPath, false);
  115.     }
  116.     // 被注释的方法
  117.     /*
  118.      * public static void encode(String content, String destPath, boolean
  119.      * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
  120.      * needCompress); }
  121.      */
  123.     public static void encode(String content, String destPath) throws Exception {
  124.         QRCodeUtil.encode(content, null, destPath, false);
  125.     }
  127.     public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
  128.             throws Exception {
  129.         BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
  130.         ImageIO.write(image, FORMAT_NAME, output);
  131.     }
  133.     public static void encode(String content, OutputStream output) throws Exception {
  134.         QRCodeUtil.encode(content, null, output, false);
  135.     }
  137.     public static String decode(File file) throws Exception {
  138.         BufferedImage image;
  139.         image = ImageIO.read(file);
  140.         if (image == null) {
  141.             return null;
  142.         }
  143.         BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
  144.         BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
  145.         Result result;
  146.         Hashtable hints = new Hashtable();
  147.         hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
  148.         result = new MultiFormatReader().decode(bitmap, hints);
  149.         String resultStr = result.getText();
  150.         return resultStr;
  151.     }
  153.     public static String decode(String path) throws Exception {
  154.         return QRCodeUtil.decode(new File(path));
  155.     }
  157. }

4,应用

  1. @ApiOperation(value = '二维码')
  2.     @PostMapping('qrcode')
  3.     public AppResponseJson qrcode() throws Exception {
  4.         // 存放在二维码中的内容
  5. 		String text = '我是小铭';
  6. 		// 嵌入二维码的图片路径
  7. 		String imgPath = 'G:/qrCode/dog.jpg';
  8. 		// 生成的二维码的路径及名称
  9. 		String destPath = 'G:/qrCode/qrcode/jam.jpg';
  10. 		//生成二维码
  11. 		QRCodeUtil.encode(text, imgPath, destPath, true);
  12. 		// 解析二维码
  13. 		String str = QRCodeUtil.decode(destPath);
  14. 		// 打印出解析出的内容
  15. 		System.out.println(str);
  16.         return AppResponseJson.successRequest('成功');
  17.     }

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）。

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