java实现二维码的生成和解析

二维码现在已经在我们的生活中大量使用，如手机支付，扫一扫登录，扫一扫加好友等。

生成二维码

添加maven依赖

<dependency>
      <groupId>com.google.zxing</groupId>
      <artifactId>javase</artifactId>
      <version>3.3.0</version>
</dependency>

使用工具生成二维码

public class Client {

  public static void main(String[] args) throws Exception {
    String content = "中国";
    Map<EncodeHintType, Object> hints = new HashMap<>();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    hints.put(EncodeHintType.MARGIN, 0);
    int onColor = 0xFF000000;     //前景色
    int offColor = 0xBFB0A8;    //背景色
    MatrixToImageConfig config = new MatrixToImageConfig(onColor, offColor);
    BitMatrix bitMatrix = new MultiFormatWriter()
        .encode(content, BarcodeFormat.QR_CODE, 300, 300, hints);
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    MatrixToImageWriter.writeToStream(bitMatrix, "png", baos, config);
    System.out.println(Base64.getEncoder().encodeToString(baos.toByteArray()));
  }

}

生成的二维码如下

zxing包提供了多种码的创建，二维码，条形码等。

解析二维码

public class Client {

  public static void main(String[] args) throws Exception {
    InputStream is = new FileInputStream("D:/a.png");
    BufferedImage image = ImageIO.read(is);
    LuminanceSource source = new BufferedImageLuminanceSource(image);
    BinaryBitmap bb = new BinaryBitmap(new HybridBinarizer(source));
    HashMap<DecodeHintType, String> hints = new HashMap<>();
    hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
    Result result = new MultiFormatReader().decode(bb, hints);
    System.out.println("二维码格式类型：" + result.getBarcodeFormat());
    System.out.println("二维码文本内容：" + result.getText());
  }

}

解析出的文本为：中国，为生成二维码时填入的内容。

生成带logo的二维码

public class Client {

  public static void main(String[] args) throws Exception {
    String content = "中国";
    Map<EncodeHintType, Object> hints = new HashMap<>();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    hints.put(EncodeHintType.MARGIN, 0);
    int onColor = 0xFF000000;     //前景色
    int offColor = 0xBFB0A8;    //背景色
    MatrixToImageConfig config = new MatrixToImageConfig(onColor, offColor);
    BitMatrix bitMatrix = new MultiFormatWriter()
        .encode(content, BarcodeFormat.QR_CODE, 300, 300, hints);
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix, config);
    addLogo(image);
    ImageIO.write(image, "png", baos);
    System.out.println(Base64.getEncoder().encodeToString(baos.toByteArray()));
  }

  private static void addLogo(BufferedImage image) throws IOException {
    Graphics2D g = image.createGraphics();
    // 读取logo图片
    InputStream logoInput = Client.class.getClassLoader().getResourceAsStream("img/wechat.png");
    if (Objects.isNull(logoInput)) {
      return;
    }
    BufferedImage logo = ImageIO.read(logoInput);
    // 设置logo的大小,本人设置为二维码图片的20%,由于过大会盖掉二维码
    int widthLogo = logo.getWidth(null) > image.getWidth() * 2 / 10 ? (image.getWidth() * 2 / 10)
        : logo.getWidth(null);
    int heightLogo = logo
        .getHeight(null) > image.getHeight() * 2 / 10 ?
        (image.getHeight() * 2 / 10) : logo.getWidth(null);

    // 计算图片放置位置
    // logo放在中心
    int x = (image.getWidth() - widthLogo) / 2;
    int y = (image.getHeight() - heightLogo) / 2;
    // 开始绘制图片
    g.drawImage(logo, x, y, widthLogo, heightLogo, null);
    g.drawRoundRect(x, y, widthLogo, heightLogo, 15, 15);
    g.drawRect(x, y, widthLogo, heightLogo);

    g.dispose();
    logo.flush();
  }

}

生成的二维码如下

生成条形码

public class Client {

  public static void main(String[] args) throws Exception {
    String content = "123456789";
    Map<EncodeHintType, Object> hints = new HashMap<>();
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    hints.put(EncodeHintType.MARGIN, 0);
    int onColor = 0xFF000000;     //前景色
    int offColor = 0xBFB0A8;    //背景色
    MatrixToImageConfig config = new MatrixToImageConfig(onColor, offColor);
    BitMatrix bitMatrix = new MultiFormatWriter()
        .encode(content, BarcodeFormat.CODE_128, 300, 100, hints);
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    MatrixToImageWriter.writeToStream(bitMatrix, "png", baos, config);
    System.out.println(Base64.getEncoder().encodeToString(baos.toByteArray()));
  }

}

BarcodeFormat.CODE_128 表示条形码
生成的条形码如下

解析条形码

public class Client {

  public static void main(String[] args) throws Exception {
    InputStream is = new FileInputStream("D:/b.png");
    BufferedImage image = ImageIO.read(is);
    LuminanceSource source = new BufferedImageLuminanceSource(image);
    BinaryBitmap bb = new BinaryBitmap(new HybridBinarizer(source));
    HashMap<DecodeHintType, String> hints = new HashMap<>();
    hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
    Result result = new MultiFormatReader().decode(bb, hints);
    System.out.println("二维码格式类型：" + result.getBarcodeFormat());
    System.out.println("二维码文本内容：" + result.getText());
  }
}

解析出的内容为：123456789