public static void outputImage()

in tsfile-viewer-web/src/main/java/org/apache/iotdb/ui/util/VerifyCodeUtils.java [142:208]
58 lines of code
5 McCabe index (conditional complexity)

  public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
    int verifySize = code.length();
    BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
    Random rand = new Random();
    Graphics2D g2 = image.createGraphics();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    Color[] colors = new Color[5];
    Color[] colorSpaces =
        new Color[] {
          Color.WHITE,
          Color.CYAN,
          Color.GRAY,
          Color.LIGHT_GRAY,
          Color.MAGENTA,
          Color.ORANGE,
          Color.PINK,
          Color.YELLOW
        };
    float[] fractions = new float[colors.length];
    for (int i = 0; i < colors.length; i++) {
      colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
      fractions[i] = rand.nextFloat();
    }
    Arrays.sort(fractions);

    g2.setColor(Color.GRAY); // 设置边框色
    g2.fillRect(0, 0, w, h);

    Color c = getRandColor(200, 250);
    g2.setColor(c); // 设置背景色
    g2.fillRect(0, 2, w, h - 4);

    // 绘制干扰线
    Random random = new Random();
    g2.setColor(getRandColor(160, 200)); // 设置线条的颜色
    for (int i = 0; i < 20; i++) {
      int x = random.nextInt(w - 1);
      int y = random.nextInt(h - 1);
      int xl = random.nextInt(6) + 1;
      int yl = random.nextInt(12) + 1;
      g2.drawLine(x, y, x + xl + 40, y + yl + 20);
    }

    // 添加噪点
    float yawpRate = 0.05f; // 噪声率
    int area = (int) (yawpRate * w * h);
    for (int i = 0; i < area; i++) {
      int x = random.nextInt(w);
      int y = random.nextInt(h);
      int rgb = getRandomIntColor();
      image.setRGB(x, y, rgb);
    }

    shear(g2, w, h, c); // 使噪音带扭曲

    g2.setColor(getRandColor(100, 160));
    int fontSize = h - 4;
    Font font = new Font("Algerian", Font.ITALIC, fontSize);
    g2.setFont(font);
    char[] chars = code.toCharArray();
    for (int i = 0; i < verifySize; i++) {
      g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 4);
    }

    g2.dispose();
    ImageIO.write(image, "jpg", os);
  }