<dependency><groupId>com.google.zxing</groupId><artifactId>core</artifactId><version>3.2.0</version></dependency>

     * 生成二维码图片* @param dir        存放的目录* @param fileName  文件名要以.jpg结尾* @param content  这个内容可以是文字或链接*/public static void generateQRCode(String dir, String fileName, String content) {//生成二维码的宽高int size = 400;Map<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();// 指定纠错等级
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定编码格式hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");// 指定二维码的边距，设置后无效，，设置纠错等级ErrorCorrectionLevel.H为高等级时，无效        //hints.put(EncodeHintType.MARGIN, 1);

        try {//encode(String contents, BarcodeFormat format, int width, int height, Map<EncodeHintType, ?> hints)BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, hints);//bitMatrix = updateBit(bitMatrix, 20);File file1 = new File(dir);if (!file1.exists()) {file1.mkdirs();}//将生成的矩阵像素写入到指定文件中，这里是以jpg结尾MatrixToImageWriter.writeToStream(bitMatrix, "jpg", new FileOutputStream(dir + "/" + fileName));System.out.println("创建成功");} catch (UnsupportedEncodingException e) {e.printStackTrace();} catch (WriterException e) {e.printStackTrace();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}

 /** L = ~7% correction */L(0x01),/** M = ~15% correction */M(0x00),/** Q = ~25% correction */Q(0x03),/** H = ~30% correction */H(0x02);

private static BitMatrix updateBit(BitMatrix matrix, int margin) {int tempM = margin * 2;//left,top,width,height // 0    1    2     3   对应的数组下标//这里的width和height是指去除白色边框后的真实的二维码长宽，而不是图片长宽。int[] rec = matrix.getEnclosingRectangle(); // 获取二维码图案的属性int resWidth = rec[2] + tempM;//真实宽度加左右边距int resHeight = rec[3] + tempM;BitMatrix resMatrix = new BitMatrix(resWidth, resHeight); // 按照自定义边框生成新的BitMatrix
resMatrix.clear();//从上->下按列进行值得复制，即一列一列的扫描到新的二维矩阵中for (int i = margin; i < resWidth - margin; i++) { // 循环，将二维码图案绘制到新的bitMatrix中for (int j = margin; j < resHeight - margin; j++) {//margin + rec[0]if (matrix.get(i - margin + rec[0], j - margin + rec[1])) {resMatrix.set(i, j);}}}return resMatrix;}

public void insertQRCode(BufferedImage zxingImage, String backgroundPath) {InputStream dest = null;try {dest = new FileInputStream(backgroundPath);BufferedImage image = ImageIO.read(dest);Graphics g = image.getGraphics();int leftMargin = image.getWidth() - zxingImage.getWidth() - 10;int topMargin = image.getHeight() - zxingImage.getHeight() - 10;g.drawImage(zxingImage, leftMargin, topMargin, zxingImage.getWidth(), zxingImage.getHeight(), null);ImageIO.write(image, "jpg", new FileOutputStream("D:\\QRCode\\zengmei.jpg"));System.out.println("创建成功");} catch (IOException e) {e.printStackTrace();}}

/*** * @param onColor 二维码的颜色，即黑白二维码的黑色 :0xFF000000  蓝色 0xFF000055* @param offColor 二维码的背景色   如白色：0xFFFFFFFF*/public static void generateOtherQRCode(int onColor, int offColor) {String content = "小姐姐最棒啦^_^";int size = 200;Map<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();// 指定纠错等级
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q);// 指定编码格式hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");try {BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, hints);BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix,new MatrixToImageConfig(onColor, offColor));ImageIO.write(image, "png", new FileOutputStream("D:/QRCode/beautiful.png"));System.out.println("操作成功");} catch (IOException e) {e.printStackTrace();} catch (WriterException e) {e.printStackTrace();}}

public static BufferedImage toBufferedImage(BitMatrix matrix, MatrixToImageConfig config) {int width = matrix.getWidth();int height = matrix.getHeight();BufferedImage image = new BufferedImage(width, height, config.getBufferedImageColorModel());int onColor = config.getPixelOnColor();int offColor = config.getPixelOffColor();for (int x = 0; x < width; x++) {for (int y = 0; y < height; y++) {image.setRGB(x, y, matrix.get(x, y) ? onColor : offColor);}}return image;}

//imageType ， zxing支持的图像类型有三种，黑白颜色的默认为BufferedImage.TYPE_BYTE_BINARY = 12，图像不带透明度alpha   最多是4bit的的图像TYPE_INT_RGB  这个是不带alpha的8bit图像TYPE_INT_ARGB 这个带alpha的8bit图像

java.awt.image.BufferedImage.BufferedImage(int width, int height, int imageType)