依賴

在Java專案中pom.xml加入：

<dependency>    <groupId>com.google.zxing</groupId>    <artifactId>core</artifactId>    <version>${version}</version></dependency><dependency>    <groupId>com.google.zxing</groupId>    <artifactId>javase</artifactId>    <version>${version}</version></dependency>

當前最新版本是3.4.1，如果是Java開發的Android專案則引入 android-core 。

生成二維碼生成普通二維碼

// 二維碼內容String text = "https://engr-z.com";// 二維碼大小int width = 500, height = 500;// 二維碼輸出檔案File file = new File("/home/engr-z/qrcode.png");QRCodeWriter writer = new QRCodeWriter();BitMatrix m = writer.encode(text, BarcodeFormat.QR_CODE, width, height);MatrixToImageWriter.writeToPath(m, "png", file.toPath());

如果內容較多，需要增大二維碼尺寸。尺寸小內容多，二維碼圖形越複雜越難識別。

生成帶Logo二維碼

// 二維碼內容String text = "https://engr-z.com";// 二維碼大小int width = 500, height = 500;// 二維碼引數CodeStyle style = new CodeStyle();style.setWidth(width);style.setHeight(height);Map<EncodeHintType, Object> hints = new HashMap<>();//內容編碼格式hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");// 指定糾錯等級hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);//設定二維碼邊的空度，非負數hints.put(EncodeHintType.MARGIN, 1);// 生成二維碼圖片QRCodeWriter writer = new QRCodeWriter();BitMatrix bm = writer.encode(text, BarcodeFormat.QR_CODE, style.getWidth(), style.getHeight(), hints);int margin = style.getMargin();int tempM = margin*2;int[] rec = bm.getEnclosingRectangle();   //獲取二維碼圖案的屬性int resWidth = rec[2] + tempM;int resHeight = rec[3] + tempM;BitMatrix resMatrix = new BitMatrix(resWidth, resHeight); // 按照自定義邊框生成新的BitMatrixresMatrix.clear();for (int i = margin; i < resWidth - margin; i++) {   //迴圈，將二維碼圖案繪製到新的bitMatrix中    for (int j = margin; j < resHeight - margin; j++){        if (bm.get(i - margin + rec[0], j - margin + rec[1])){            resMatrix.set(i, j);        }    }}bm = resMatrix;int w = bm.getWidth();int h = bm.getHeight();BufferedImage qrcodeBuffImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);// 開始利用二維碼資料建立Bitmap圖片for (int x = 0; x < w; x++) {    for (int y = 0; y < h; y++) {        qrcodeBuffImg.setRGB(x, y, bm.get(x, y) ? style.getCodeColor() : style.getBackgroundColor());    }}/** * 讀取Logo圖片 */File logoFile = new File("/home/engr-z/logo.png");BufferedImage logo = ImageIO.read(logoFile);/** * 設定logo的大小，設定為二維碼圖片的20% */int widthLogo = logo.getWidth(null) > qrcodeBuffImg.getWidth() * 3 / 10 ? (qrcodeBuffImg.getWidth() * 3 / 10)        : logo.getWidth(null),        heightLogo = logo.getHeight(null) > qrcodeBuffImg.getHeight() * 3 / 10 ? (qrcodeBuffImg.getHeight() * 3 / 10) : logo.getWidth(null);/** * logo在二維碼的位置 */int x = (qrcodeBuffImg.getWidth() - widthLogo) / 2;int y = (qrcodeBuffImg.getHeight() - heightLogo) / 2;Graphics2D qrcodeOutg = qrcodeBuffImg.createGraphics();// 把logo寫到二維碼圖片中間qrcodeOutg.drawImage(logo, x, y, widthLogo, heightLogo, null);qrcodeOutg.dispose();qrcodeBuffImg.flush();// 新的圖片，把帶logo的二維碼下面加上文字String desc = "https://engr-z.com";int textHeight = 26;int textMargin = 10;BufferedImage outImage = new BufferedImage(qrcodeBuffImg.getWidth(), qrcodeBuffImg.getHeight() + textHeight + (textMargin * 2), BufferedImage.TYPE_4BYTE_ABGR);Graphics2D outg = outImage.createGraphics();// 畫二維碼到新的面板outg.drawImage(qrcodeBuffImg, 0, 0, qrcodeBuffImg.getWidth(), qrcodeBuffImg.getHeight(), null);outg.setFont(new Font("宋體", Font.BOLD, 26)); // 字型、字型、字號int strWidth = outg.getFontMetrics().stringWidth(desc);outg.setColor(Color.BLACK);outg.drawString(desc, (outImage.getWidth() - strWidth) / 2, outImage.getHeight() - textMargin);outg.dispose();// 二維碼輸出檔案File file = new File("/home/engr-z/qrcode.png");ImageIO.write(outImage, "png", file);

CodeStyle是我封裝的類，用來設定二維碼樣式：

/** * @author Engr-Z * @since 2020/12/18 */@Datapublic class CodeStyle {    /**     * 背景顏色，如：0xFFFFFFFF     */    private int backgroundColor = 0xFFFFFFFF;    /**     * 碼顏色，如：0xFF000000     */    private int codeColor = 0xFF000000;    /**     * 二維碼寬，px     */    private int width;    /**     * 二維碼高，px     */    private int height;    /**     * 邊框大小     */    private int margin = 5;}

以下是我執行生成的二維碼：

讀取二維碼

File qrcodeFile = new File("D:/qrcode.png");BufferedImage qrcodeImg = ImageIO.read(qrcodeFile);MultiFormatReader formatReader = new MultiFormatReader();//讀取指定的二維碼檔案BinaryBitmap binaryBitmap= new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(qrcodeImg)));//定義二維碼引數Map<DecodeHintType, Object> hints= new HashMap<>();hints.put(DecodeHintType.CHARACTER_SET, "utf-8");// 讀取Result result = formatReader.decode(binaryBitmap, hints);log.info("格式型別：{}", result.getBarcodeFormat());log.info("二維碼內容：{}", result.getText());

連結

ZXing GitHub：https://github.com/zxing/zxing

本文連結：https://engr-z.com/292.html