public static String getCaptcha(HttpServletRequest request, HttpServletResponse response) {
try {
final String captchaSizeConfigName =
StringUtils.defaultIfEmpty(request.getParameter("captchaSize"), "default");
final String captchaSizeConfig =
UtilProperties.getPropertyValue("captcha.properties", "captcha." + captchaSizeConfigName);
final String[] captchaSizeConfigs = captchaSizeConfig.split("\\|");
final String captchaCodeId =
StringUtils.defaultIfEmpty(
request.getParameter("captchaCodeId"),
""); // this is used to uniquely identify in the user session the attribute where the
// captcha code for the last captcha for the form is stored
final int fontSize = Integer.parseInt(captchaSizeConfigs[0]);
final int height = Integer.parseInt(captchaSizeConfigs[1]);
final int width = Integer.parseInt(captchaSizeConfigs[2]);
final int charsToPrint =
UtilProperties.getPropertyAsInteger("captcha.properties", "captcha.code_length", 6);
final char[] availableChars =
UtilProperties.getPropertyValue("captcha.properties", "captcha.characters").toCharArray();
// It is possible to pass the font size, image width and height with the request as well
Color backgroundColor = Color.gray;
Color borderColor = Color.DARK_GRAY;
Color textColor = Color.ORANGE;
Color circleColor = new Color(160, 160, 160);
Font textFont = new Font("Arial", Font.PLAIN, fontSize);
int circlesToDraw = 6;
float horizMargin = 20.0f;
double rotationRange = 0.7; // in radians
BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D) bufferedImage.getGraphics();
g.setColor(backgroundColor);
g.fillRect(0, 0, width, height);
// Generating some circles for background noise
g.setColor(circleColor);
for (int i = 0; i < circlesToDraw; i++) {
int circleRadius = (int) (Math.random() * height / 2.0);
int circleX = (int) (Math.random() * width - circleRadius);
int circleY = (int) (Math.random() * height - circleRadius);
g.drawOval(circleX, circleY, circleRadius * 2, circleRadius * 2);
}
g.setColor(textColor);
g.setFont(textFont);
FontMetrics fontMetrics = g.getFontMetrics();
int maxAdvance = fontMetrics.getMaxAdvance();
int fontHeight = fontMetrics.getHeight();
String captchaCode = RandomStringUtils.random(6, availableChars);
float spaceForLetters = -horizMargin * 2 + width;
float spacePerChar = spaceForLetters / (charsToPrint - 1.0f);
for (int i = 0; i < captchaCode.length(); i++) {
// this is a separate canvas used for the character so that
// we can rotate it independently
int charWidth = fontMetrics.charWidth(captchaCode.charAt(i));
int charDim = Math.max(maxAdvance, fontHeight);
int halfCharDim = (charDim / 2);
BufferedImage charImage = new BufferedImage(charDim, charDim, BufferedImage.TYPE_INT_ARGB);
Graphics2D charGraphics = charImage.createGraphics();
charGraphics.translate(halfCharDim, halfCharDim);
double angle = (Math.random() - 0.5) * rotationRange;
charGraphics.transform(AffineTransform.getRotateInstance(angle));
charGraphics.translate(-halfCharDim, -halfCharDim);
charGraphics.setColor(textColor);
charGraphics.setFont(textFont);
int charX = (int) (0.5 * charDim - 0.5 * charWidth);
charGraphics.drawString(
"" + captchaCode.charAt(i),
charX,
((charDim - fontMetrics.getAscent()) / 2 + fontMetrics.getAscent()));
float x = horizMargin + spacePerChar * (i) - charDim / 2.0f;
int y = ((height - charDim) / 2);
g.drawImage(charImage, (int) x, y, charDim, charDim, null, null);
charGraphics.dispose();
}
// Drawing the image border
g.setColor(borderColor);
g.drawRect(0, 0, width - 1, height - 1);
g.dispose();
response.setContentType("image/jpeg");
ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
HttpSession session = request.getSession();
Map captchaCodeMap = (Map) session.getAttribute("_CAPTCHA_CODE_");
if (captchaCodeMap == null) {
captchaCodeMap = new HashMap();
session.setAttribute("_CAPTCHA_CODE_", captchaCodeMap);
}
captchaCodeMap.put(captchaCodeId, captchaCode);
} catch (Exception ioe) {
Debug.logError(ioe.getMessage(), module);
}
return "success";
}
