ZXing 生成、读取二维码(带logo)

  前言

  ZXing,一个支持在图像中解码和生成条形码(如二维码、PDF 417、EAN、UPC、Aztec、Data Matrix、Codabar)的库。ZXing(“zebra crossing”)是一个开源的、多格式的、用Java实现的一维/二维条码图像处理库,具有到其他语言的端口。

  GitHub地址,猛戳:https://github.com/zxing/zxing

  API文档,猛戳:https://zxing.github.io/zxing/apidocs/index.html

  介绍文档,猛戳:https://zxing.github.io/zxing/

 

  代码编写

  部分代码参考:https://blog.csdn.net/weixin_39494923/article/details/79058799

  maven

  我们是java端,所以需要引这两个

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

  Test.java

public class Test{

    public static void main(String[] args) {
        try {
            QREncode();

            QRReader(new File("D:\\zxing1.gif"));
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (NotFoundException e) {
            e.printStackTrace();
        }
    }

    /**
     * 生成二维码
     */
    public static void QREncode() throws WriterException, IOException {
        String content = "个人博客:https://www.cnblogs.com/huanzi-qch/";//二维码内容
        int width = 200; // 图像宽度
        int height = 200; // 图像高度
        String format = "gif";// 图像类型
        Map<EncodeHintType, Object> hints = new HashMap<>();
        //内容编码格式
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        // 指定纠错等级
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        //设置二维码边的空度,非负数
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        MatrixToImageWriter.writeToPath(bitMatrix, format, new File("D:\\zxing.gif").toPath());// 输出原图片
        MatrixToImageConfig matrixToImageConfig = new MatrixToImageConfig(0xFF000001, 0xFFFFFFFF);
        /*
            问题:生成二维码正常,生成带logo的二维码logo变成黑白
            原因:MatrixToImageConfig默认黑白,需要设置BLACK、WHITE
            解决:https://ququjioulai.iteye.com/blog/2254382
         */
        BufferedImage bufferedImage = LogoMatrix(MatrixToImageWriter.toBufferedImage(bitMatrix,matrixToImageConfig), new File("D:\\logo.png"));
//        BufferedImage bufferedImage = LogoMatrix(toBufferedImage(bitMatrix), new File("D:\\logo.png"));
        ImageIO.write(bufferedImage, "gif", new File("D:\\zxing1.gif"));//输出带logo图片
        System.out.println("输出成功.");
    }

    /**
     * 识别二维码
     */
    public static void QRReader(File file) throws IOException, NotFoundException {
        MultiFormatReader formatReader = new MultiFormatReader();
        //读取指定的二维码文件
        BufferedImage bufferedImage =ImageIO.read(file);
        BinaryBitmap binaryBitmap= new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(bufferedImage)));
        //定义二维码参数
        Map  hints= new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        com.google.zxing.Result result = formatReader.decode(binaryBitmap, hints);
        //输出相关的二维码信息
        System.out.println("解析结果:"+result.toString());
        System.out.println("二维码格式类型:"+result.getBarcodeFormat());
        System.out.println("二维码文本内容:"+result.getText());
        bufferedImage.flush();
    }

    /**
     * 二维码添加logo
     * @param matrixImage 源二维码图片
     * @param logoFile logo图片
     * @return 返回带有logo的二维码图片
     * 参考:https://blog.csdn.net/weixin_39494923/article/details/79058799
     */
    public static BufferedImage LogoMatrix(BufferedImage matrixImage, File logoFile) throws IOException{
        /**
         * 读取二维码图片,并构建绘图对象
         */
        Graphics2D g2 = matrixImage.createGraphics();

        int matrixWidth = matrixImage.getWidth();
        int matrixHeigh = matrixImage.getHeight();

        /**
         * 读取Logo图片
         */
        BufferedImage logo = ImageIO.read(logoFile);

        //开始绘制图片
        g2.drawImage(logo,matrixWidth/5*2,matrixHeigh/5*2, matrixWidth/5, matrixHeigh/5, null);//绘制
        BasicStroke stroke = new BasicStroke(5,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
        g2.setStroke(stroke);// 设置笔画对象
        //指定弧度的圆角矩形
        RoundRectangle2D.Float round = new RoundRectangle2D.Float(matrixWidth/5*2, matrixHeigh/5*2, matrixWidth/5, matrixHeigh/5,20,20);
        g2.setColor(Color.white);
        g2.draw(round);// 绘制圆弧矩形

        //设置logo 有一道灰色边框
        BasicStroke stroke2 = new BasicStroke(1,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
        g2.setStroke(stroke2);// 设置笔画对象
        RoundRectangle2D.Float round2 = new RoundRectangle2D.Float(matrixWidth/5*2+2, matrixHeigh/5*2+2, matrixWidth/5-4, matrixHeigh/5-4,20,20);
        g2.setColor(new Color(128,128,128));
        g2.draw(round2);// 绘制圆弧矩形

        g2.dispose();
        matrixImage.flush() ;
        return matrixImage ;
    }
}

  

  效果演示

  D盘文件

  查看图片

  后台识别、微信扫描结果

 

 

  后记

  后端生成我们可以用ZXing框架,那么前端js又应该如何生成、识别二维码呢?QRCode.js,QRCode.js 是一个用于生成二维码的 JavaScript 库。主要是通过获取 DOM 的标签,再通过 HTML5 Canvas 绘制而成,不依赖任何库。菜鸟教程,猛戳:http://www.runoob.com/w3cnote/javascript-qrcodejs-library.html

  但是qrcode默认不支持自定义logo,怎么办呢?两种方法:

  1、创建一个img标签,调整样式,让logo在二维码区域上居中显示

  2、创建一个canvas画布,将二维码跟logo重新绘制,让logo在二维码区域上居中显示

 

  补充

  2020-02-25补充:实现二维码输出到浏览器功能

  1、生成二维码时,不是直接保存成图片,而是返回BufferedImage

    /**
     * 生成二维码
     */
    public static BufferedImage QREncode(String content){
        int width = 250; // 图像宽度
        int height = 250; // 图像高度
        Map<EncodeHintType, Object> hints = new HashMap<>();
        //内容编码格式
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        // 指定纠错等级
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        //设置二维码边的空度,非负数
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = null;
        BufferedImage bufferedImage = null;
        try {
            bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, width, height, hints);

            MatrixToImageConfig matrixToImageConfig = new MatrixToImageConfig(0xFF000001, 0xFFFFFFFF);
            bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix,matrixToImageConfig);
        } catch (WriterException e) {
            e.printStackTrace();
        }

        //无logo
        //return bufferedImage;

        //带logo,System.getProperty("user.dir")是项目工程根路径
        assert bufferedImage != null;
        return LogoMatrix(bufferedImage,new File(System.getProperty("user.dir") + "\\src\\main\\resources\\static\\img\\logo.png"));
    }

  2、新增controller,供web调用

    //获取二维码图片
    @GetMapping("getBarCodeImage/{id}")
    public void getBarCodeImage(@PathVariable("id") String id) throws IOException {
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest();
        HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getResponse();

        //设置页面不缓存
        assert response != null;
        response.setHeader("Pragma", "no-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        response.getOutputStream();

        //设置输出的内容的类型为JPEG图像
        response.setContentType("image/jpeg");

        //通过id查询数据设置二维码内容
        String text = "{\"id\":\""+ id +"\"}"

        BufferedImage bufferedImage = QREncode(text);

        //写给浏览器
        ImageIO.write(bufferedImage, "JPEG", response.getOutputStream());
    }

     3、web页面调用,thymeleaf语法

<img id="barCodeImage" th:src="@{'/getBarCodeImage/' + ${id}}"/>
<br/><br/>
<button th:onclick="${'document.getElementById(''barCodeImage'').src = ctx + ''/getBarCodeImage/'+ id +'?time='' + new Date().getTime()'}">
刷新二维码
</button>

 

posted @ 2018-12-10 17:39  huanzi-qch  阅读(53194)  评论(4编辑  收藏  举报