java實現二維碼的生成和解析

二維碼現在已經在我們的生活中大量使用，如手機支付，掃一掃登錄，掃一掃加好友等。

生成二維碼

添加maven依賴

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

使用工具生成二維碼

public class Client {

  public static void main(String[] args) throws Exception {
    String content = "中國";
    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()));
  }

}

生成的二維碼如下

zxing包提供了多種碼的創建，二維碼，條形碼等。

解析二維碼

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("二維碼格式類型：" + result.getBarcodeFormat());
    System.out.println("二維碼文本內容：" + result.getText());
  }

}

解析出的文本為：中國，為生成二維碼時填入的內容。

生成帶logo的二維碼

public class Client {

  public static void main(String[] args) throws Exception {
    String content = "中國";
    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();
    // 讀取logo圖片
    InputStream logoInput = Client.class.getClassLoader().getResourceAsStream("img/wechat.png");
    if (Objects.isNull(logoInput)) {
      return;
    }
    BufferedImage logo = ImageIO.read(logoInput);
    // 設置logo的大小,本人設置為二維碼圖片的20%,由於過大會蓋掉二維碼
    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);

    // 計算圖片放置位置
    // logo放在中心
    int x = (image.getWidth() - widthLogo) / 2;
    int y = (image.getHeight() - heightLogo) / 2;
    // 開始繪制圖片
    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();
  }

}

生成的二維碼如下

生成條形碼

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 表示條形碼
生成的條形碼如下

解析條形碼

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("二維碼格式類型：" + result.getBarcodeFormat());
    System.out.println("二維碼文本內容：" + result.getText());
  }
}

解析出的內容為：123456789