Java 实现定制二维码，附源码

来源：http://suo.im/5R6ewH

步骤 1

第一步首先创建一个普通的 Maven 项目，然后要实现二维码功能，我们肯定要使用别人提供好的 Jar 包，这里我用的是 google 提供的 jar，pom.xml 文件配置如下：

<?xml version='1.0' encoding='UTF-8'?><project xmlns='http://maven.apache.org/POM/4.0.0' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd'> <modelVersion>4.0.0</modelVersion>
 <groupId>org.javaboy</groupId> <artifactId>QRCode</artifactId> <version>1.0-SNAPSHOT</version>

 <dependencies> <!-- 添加 google 提供的二维码依赖 --> <dependency> <groupId>com.google.zxing</groupId> <artifactId>core</artifactId> <version>3.3.0</version> </dependency> </dependencies>
</project>

步骤 2

然后使用 google 提供的工具类，在项目根目录下创建一个 util 包，将所需要的工具类放进去。

工具类1 (BufferedImageLuminanceSource)

不废话，直接上代码

/** * @author bai <br/> * @date 2020/7/1 9:27<br/> */public class BufferedImageLuminanceSource extends LuminanceSource {    private final BufferedImage image;    private final int left;    private final int top;    public BufferedImageLuminanceSource(BufferedImage image) {        this(image, 0, 0, image.getWidth(), image.getHeight());    }    public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {        super(width, height);        int sourceWidth = image.getWidth();        int sourceHeight = image.getHeight();        if (left + width > sourceWidth || top + height > sourceHeight) {            throw new IllegalArgumentException('Crop rectangle does not fit within image data.');        }        for (int y = top; y < top + height; y++) {            for (int x = left; x < left + width; x++) {                if ((image.getRGB(x, y) & 0xFF000000) == 0) {                    image.setRGB(x, y, 0xFFFFFFFF); // = white                }            }        }        this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);        this.image.getGraphics().drawImage(image, 0, 0, null);        this.left = left;        this.top = top;    }    @Override    public byte[] getRow(int y, byte[] row) {        if (y < 0 || y >= getHeight()) {            throw new IllegalArgumentException('Requested row is outside the image: ' + y);        }        int width = getWidth();        if (row == null || row.length < width) {            row = new byte[width];        }        image.getRaster().getDataElements(left, top + y, width, 1, row);        return row;    }    @Override    public byte[] getMatrix() {        int width = getWidth();        int height = getHeight();        int area = width * height;        byte[] matrix = new byte[area];        image.getRaster().getDataElements(left, top, width, height, matrix);        return matrix;    }    @Override    public boolean isCropSupported() {        return true;    }    @Override    public LuminanceSource crop(int left, int top, int width, int height) {        return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);    }    @Override    public boolean isRotateSupported() {        return true;    }    @Override    public LuminanceSource rotateCounterClockwise() {        int sourceWidth = image.getWidth();        int sourceHeight = image.getHeight();        AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);        BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);        Graphics2D g = rotatedImage.createGraphics();        g.drawImage(image, transform, null);        g.dispose();        int width = getWidth();        return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);    }}

工具类2 (QRCodeUtil)

这里面可以修改一些参数，例如二维码的尺寸，宽高等等。

/** * @author bai <br/> * @date 2020/7/1 9:29<br/> */public class QRCodeUtil { private static final String CHARSET = 'utf-8'; private static final String FORMAT_NAME = 'JPG'; // 二维码尺寸 private static final int QRCODE_SIZE = 300; // LOGO宽度 private static final int WIDTH = 60; // LOGO高度 private static final int HEIGHT = 60;
 private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception { Hashtable hints = new Hashtable(); hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); hints.put(EncodeHintType.CHARACTER_SET, CHARSET); hints.put(EncodeHintType.MARGIN, 1); BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints); 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); } } if (imgPath == null || ''.equals(imgPath)) { return image; } // 插入图片 QRCodeUtil.insertImage(image, imgPath, needCompress); return image; }
 private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception { File file = new File(imgPath); if (!file.exists()) { System.err.println('' + imgPath + ' 该文件不存在！'); return; } Image src = ImageIO.read(new File(imgPath)); int width = src.getWidth(null); int height = src.getHeight(null); if (needCompress) { // 压缩LOGO if (width > WIDTH) { width = WIDTH; } if (height > HEIGHT) { height = HEIGHT; } Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH); BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(image, 0, 0, null); // 绘制缩小后的图 g.dispose(); src = image; } // 插入LOGO Graphics2D graph = source.createGraphics(); int x = (QRCODE_SIZE - width) / 2; int y = (QRCODE_SIZE - height) / 2; graph.drawImage(src, x, y, width, height, null); Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6); graph.setStroke(new BasicStroke(3f)); graph.draw(shape); graph.dispose(); }
 public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); mkdirs(destPath); // String file = new Random().nextInt(99999999)+'.jpg'; // ImageIO.write(image, FORMAT_NAME, new File(destPath+'/'+file)); ImageIO.write(image, FORMAT_NAME, new File(destPath)); }
 public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); return image; }
 public static void mkdirs(String destPath) { File file = new File(destPath); // 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) if (!file.exists() && !file.isDirectory()) { file.mkdirs(); } }
 public static void encode(String content, String imgPath, String destPath) throws Exception { QRCodeUtil.encode(content, imgPath, destPath, false); } // 被注释的方法 /* * public static void encode(String content, String destPath, boolean * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath, * needCompress); } */
 public static void encode(String content, String destPath) throws Exception { QRCodeUtil.encode(content, null, destPath, false); }
 public static void encode(String content, String imgPath, OutputStream output, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); ImageIO.write(image, FORMAT_NAME, output); }
 public static void encode(String content, OutputStream output) throws Exception { QRCodeUtil.encode(content, null, output, false); }
 public static String decode(File file) 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, CHARSET); result = new MultiFormatReader().decode(bitmap, hints); String resultStr = result.getText(); return resultStr; }
 public static String decode(String path) throws Exception { return QRCodeUtil.decode(new File(path)); }
}

启动类

这一步就是调用方法，一般大家使用这种功能都是为了实现业务，例如常见的扫描二维码跳转链接（页面），扫描二维码出现文字等等。有些二维码中间还带有 Logo 这种图片，将需要嵌入二维码的图片路径准备好就没有问题。

/** * @author bai <br/> * @date 2020/7/1 9:31<br/> */public class QRCodeApplication {    public static void main(String[] args) throws Exception {        // 存放在二维码中的内容        // 二维码中的内容可以是文字，可以是链接等        String text = 'http://www.baidu.com';        // 嵌入二维码的图片路径        //String imgPath = 'C:\\Users\\Administrator\\Pictures\\img\\dog.jpg';        // 生成的二维码的路径及名称        String destPath = 'C:\\Users\\bai\\Pictures\\img\\code' + System.currentTimeMillis() + '.jpg';        //生成二维码        QRCodeUtil.encode(text, null, destPath, true);        // 解析二维码        String str = QRCodeUtil.decode(destPath);        // 打印出解析出的内容        System.out.println(str);    }}

效果截图

源码奉上

码云：https://gitee.com/jian_bo_bai/QRCode

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