Java实现二维码的生成和解析

Posted 2022-08-23 java李杨勇

最近因个人需求需要对根据内容生成二维码和进行解析！记录一下！二维码其实就是一种编码技术，只是这种编码技术是用在图片上了，将给定的一些文字，数字转换为一张经过特定编码的图片。这里利用的是 google 公司的 zxing使用方便，可以操作条形码或者二维码等

导入相关jar包:

<!-- 二维码 -->
		<dependency>
			<groupId>com.google.zxing</groupId>
			<artifactId>core</artifactId>
			<version>3.3.0</version>
		</dependency>
		<dependency>
			<groupId>com.google.zxing</groupId>
			<artifactId>javase</artifactId>
			<version>3.3.3</version>
		</dependency>

二维码工具类编：

 创建二维码图片：

public static BufferedImage createImage(String charSet, String content, int qrWidth, int qrHeight) 
        Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, charSet);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = null;
        try 
            bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, qrWidth, qrHeight, // 修改二维码底部高度
                    hints);
         catch (WriterException e) 
            e.printStackTrace();
        
        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);
            
        
        return image;
    

二维码设置logo:

public static void insertLogoImage(BufferedImage source, Image logo, int logoWidth, int logoHeight) 
        Graphics2D graph = source.createGraphics();
        int qrWidth = source.getWidth();
        int qrHeight = source.getHeight();
        int x = (qrWidth - logoWidth) / 2;
        int y = (qrHeight - logoHeight) / 2;
        graph.drawImage(logo, x, y, logoWidth, logoHeight, null);
        Shape shape = new RoundRectangle2D.Float(x, y, logoWidth, logoHeight, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    

将文明说明增加到二维码上:

 public static BufferedImage textToImage(String str, int width, int height, int fontSize) 
        BufferedImage textImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) textImage.getGraphics();
        //开启文字抗锯齿
        g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        g2.setBackground(Color.WHITE);
        g2.clearRect(0, 0, width, height);
        g2.setPaint(Color.BLACK);
        FontRenderContext context = g2.getFontRenderContext();
        Font font = new Font("微软雅黑", Font.PLAIN, fontSize);
        g2.setFont(font);
        LineMetrics lineMetrics = font.getLineMetrics(str, context);
        FontMetrics fontMetrics = FontDesignMetrics.getMetrics(font);
        float offset = (width - fontMetrics.stringWidth(str)) / 2;
        float y = (height + lineMetrics.getAscent() - lineMetrics.getDescent() - lineMetrics.getLeading()) / 2;
        g2.drawString(str, (int) offset, (int) y);
        return textImage;
    

解析二维码：

 /*
     * 解析二维码
     */
    public static String decode(File file, DecodeHintType cherSet) 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, cherSet);
        hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
        hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);

        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    

main方法测试类：

  public static void main(String[] args) 
        String content="用户摄影作品版权信息";
        BufferedImage image = QRCodeUtil.createImage( "utf-8", content, 400, 400 );
        QRCodeUtil.addUpFont( image,"用户摄影作品版权信息" );
        String formatName="png";
        String imagePath="D:\\\\temp\\\\java二维码.png";
        File file=new File(imagePath);
        try 
            ImageIO.write(image, formatName, file);
         catch (IOException e) 
            e.printStackTrace();
        
        String decode = null;
        try 
            decode = QRCodeUtil.decode(file, DecodeHintType.CHARACTER_SET);
         catch (Exception e) 
            e.printStackTrace();
        
        System.out.println(decode);
        System.out.println("执行完成");

    

这样就实现了 ！二维码里面的内容根据实际数据来就行！用手机扫描后查看。