Java Captcha类代码示例

import nl.captcha.Captcha; //导入依赖的package包/类
private void getCaptchaImage(HttpServletRequest request, HttpServletResponse response) throws IOException
{
	String seed = request.getParameter("seed");
	if (seed == null || seed.isEmpty())
	{
		response.sendError(HttpServletResponse.SC_NOT_ACCEPTABLE);
		return;
	}
	int seed_;
	try
	{
		seed_ = Integer.parseInt(seed);
	}
	catch (NumberFormatException i)
	{
		response.sendError(HttpServletResponse.SC_NOT_ACCEPTABLE);
		return;
	}
	PredictableCaptchaTextProducer producer = new PredictableCaptchaTextProducer(seed_);
	final Captcha captcha = new Captcha.Builder(160, 50).addText(producer).addBackground(new GradiatedBackgroundProducer()).addNoise().gimp(new FishEyeGimpyRenderer()).addBorder().build();
	CaptchaServletUtil.writeImage(response, captcha.getImage());
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
		
		List<java.awt.Font> textFonts = Arrays.asList(
		     new Font("Arial", Font.BOLD, 40), 
		     new Font("Courier", Font.BOLD, 40));
	    Captcha captcha = new Captcha.Builder(250, 90).addText()
			.addBackground(new FlatColorBackgroundProducer(Color.YELLOW))
			.gimp(new FishEyeGimpyRenderer())
			.addNoise(new CurvedLineNoiseProducer())
			.addText(new DefaultTextProducer(5), 
					 new DefaultWordRenderer(Color.RED, textFonts))
			.build();

	    CaptchaServletUtil.writeImage(resp, captcha.getImage());
	    req.getSession().setAttribute(NAME, captcha);
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@Test
public void testShouldExpire() {
    Captcha captcha = new Captcha.Builder(200, 50)
        .addText()
        .build();
    
    assertFalse(StickyCaptchaServlet.shouldExpire(captcha));
    
    StickyCaptchaServlet.setTtl(0);
    assertTrue(StickyCaptchaServlet.shouldExpire(captcha));
    
    assertEquals(0, StickyCaptchaServlet.getTtl());
    StickyCaptchaServlet.setTtl(-1000);
    assertEquals(0, StickyCaptchaServlet.getTtl());
    
    StickyCaptchaServlet.setTtl(Long.MAX_VALUE);
    assertFalse(StickyCaptchaServlet.shouldExpire(captcha));
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
public boolean isValid(HttpSession session) {
  Captcha captchaValue = (Captcha) session.getAttribute(Captcha.NAME);
  session.removeAttribute(Captcha.NAME);
  if (captchaValue == null || captcha == null ||
      !captchaValue.isCorrect(captcha)) {
    errors.put("captchaError", "Text did not match image");
  }
  if (!StringUtils.hasText(getNameFirst())) {
    errors.put("nameFirstError", "Required field");
  }
  if (!StringUtils.hasText(getNameLast())) {
    errors.put("nameLastError", "Required field");
  }
  if (!StringUtils.hasText(getEmail())) {
    errors.put("emailError", "Required field");
  }
  if (!StringUtils.hasText(getDescription())) {
    errors.put("descriptionError", "Required field");
  }
  return (!hasErrors());
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@Override
public void doGet(final HttpServletRequest req, final HttpServletResponse resp)
    throws ServletException,
    IOException {
    final HttpSession session = req.getSession();

    final Captcha captcha = new Captcha.Builder(_width, _height)
        .addText()
        .addBackground(new GradiatedBackgroundProducer())
        .gimp()
        .addBackground(new FlatColorBackgroundProducer(new Color(238, 238, 238)))
        .addBorder()
        .addNoise()
        .build();

    session.setAttribute(NAME, captcha);

    CaptchaServletUtil.writeImage(resp, captcha.getImage());
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@At("/captcha/update")
	@Ok("raw:image/png")
	public BufferedImage updateCaptcha(HttpSession session, @Param("w") int w, @Param("h") int h) {
		if (w * h == 0) { //长或宽为0?重置为默认长宽.
			w = 200;
			h = 60;
		}
		Captcha captcha = new Captcha.Builder(w, h)
								.addText().addBackground(new GradiatedBackgroundProducer())
//								.addNoise(new StraightLineNoiseProducer()).addBorder()
								.gimp(new FishEyeGimpyRenderer())
								.build();
		String text = captcha.getAnswer();
		session.setAttribute(Toolkit.captcha_attr, text);
		return captcha.getImage();
	}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    //ColoredEdgesWordRenderer wordRenderer = new ColoredEdgesWordRenderer(COLORS, FONTS);
    ColoredEdgesWordRenderer wordRenderer = new ColoredEdgesWordRenderer(COLORS, FONTS, 1f);
    Captcha captcha = new Captcha.Builder(_width, _height).addText(wordRenderer)
            //.gimp()
            .addNoise()
            //.addBackground(new GradiatedBackgroundProducer())
            //.addBackground(new TransparentBackgroundProducer())
            //.addBackground(new FlatColorBackgroundProducer(Color.lightGray))
            .addBackground(new GradiatedBackgroundProducer(Color.lightGray, Color.white))
            .build();

    CaptchaServletUtil.writeImage(resp, captcha.getImage());
    req.getSession().setAttribute(NAME, captcha);
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
public static boolean validateSimpleCaptcha( HttpSession session, String answer) {
    Captcha captcha = (Captcha) session.getAttribute( Captcha.NAME );
    String code = captcha.getAnswer();
    if( code.equals(answer) ) {
        return true;
    }
    return false;
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    ColoredEdgesWordRenderer wordRenderer = new ColoredEdgesWordRenderer(COLORS, FONTS);
    Captcha captcha = new Captcha.Builder(_width, _height).addText(wordRenderer)
            .gimp()
            .addNoise()
            .addBackground(new GradiatedBackgroundProducer())
            .build();

    CaptchaServletUtil.writeImage(resp, captcha.getImage());
    req.getSession().setAttribute(NAME, captcha);
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
private Captcha buildAndSetCaptcha(HttpSession session) {
    Captcha captcha = new Captcha.Builder(_width, _height)
        .addText()
        .gimp()
        .addBorder()
        .addNoise()
        .addBackground()
        .build();

    session.setAttribute(NAME, captcha);
    return captcha;
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
static boolean shouldExpire(Captcha captcha) {
    long ts = captcha.getTimeStamp().getTime();
    long now = new Date().getTime();
    long diff = now - ts;

    return diff >= _ttl;
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
/**
 * Gets the valid attribute of the UserBean object
 *
 * @param session the browser sessions
 * @return The valid value
 */
public boolean isValid(HttpSession session) {
  Captcha captchaValue = (Captcha) session.getAttribute(Captcha.NAME);
  session.removeAttribute(Captcha.NAME);
  if (captchaValue == null || captcha == null ||
      !captchaValue.isCorrect(captcha)) {
    errors.put("captchaError", "Text did not match image");
  }
  if (!StringUtils.hasText(nameFirst)) {
    errors.put("nameFirstError", "Required field");
  }
  if (!StringUtils.hasText(nameLast)) {
    errors.put("nameLastError", "Required field");
  }
  if (!StringUtils.hasText(companyName)) {
    errors.put("companyNameError", "Required field");
  }
  if (!StringUtils.hasText(email)) {
    errors.put("emailError", "Required field");
  }
  if (!StringUtils.hasText(phone)) {
    errors.put("phoneError", "Required field");
  }
  if (!StringUtils.hasText(addressLine1)) {
    errors.put("addressLine1Error", "Required field");
  }
  if (!StringUtils.hasText(getCity())) {
    errors.put("cityError", "Required field");
  }
  if (getState() == null || getState().equals("-1")) {
    errors.put("stateError", "Required field");
  }
  if (getCountry() == null || getCountry().equals("-1")) {
    errors.put("countryError", "Required field");
  }
  if (!agreement) {
    errors.put("agreementError", "Accepting the terms and conditions is required");
  }
  return (!hasErrors());
}
 

import nl.captcha.Captcha; //导入依赖的package包/类
private String validateCaptcha(HttpServletRequest request,
      String returnIncompleteState) throws Exception {
      Captcha captcha = (Captcha) request.getSession().getAttribute(Captcha.NAME);
      if (captcha == null) {
          captcha = new Captcha.Builder(200, 50).addText().addBackground()
              // .addNoise()
              .gimp()
              // .addBorder()
              .build();
          request.getSession().setAttribute(Captcha.NAME, captcha);
      }

      // Do this so we can capture non-Latin chars
      request.setCharacterEncoding("UTF-8");
      String answer = HTTPUtils.cleanXSS((String) request.getParameter("answer"));
      if (answer == null || answer.length() == 0) {
          throw new NoReloadException(
              "Please enter the characters appearing in the image. ");
      }

      request.getSession().removeAttribute("reload");
      if (!captcha.isCorrect(answer)) {
          throw new InvalidCaptChaInputException(
              "WARNING: The string you entered does not match"
                  + " with what is shown in the image. Please try again.");
}
request.getSession().removeAttribute(Captcha.NAME);
      return null;
  }
 

import nl.captcha.Captcha; //导入依赖的package包/类
private String validateCaptcha(HttpServletRequest request,
      String returnIncompleteState) throws Exception {
      Captcha captcha = (Captcha) request.getSession().getAttribute(Captcha.NAME);
      if (captcha == null) {
          captcha = new Captcha.Builder(200, 50).addText().addBackground()
              // .addNoise()
              .gimp()
              // .addBorder()
              .build();
          request.getSession().setAttribute(Captcha.NAME, captcha);
      }

      // Do this so we can capture non-Latin chars
      request.setCharacterEncoding("UTF-8");
      String answer = HTTPUtils.cleanXSS((String) request.getParameter("answer"));
      if (answer == null || answer.length() == 0) {
          throw new NoReloadException(
              "Please enter the characters appearing in the image. ");
      }

      request.getSession().removeAttribute("reload");
      if (!captcha.isCorrect(answer)) {
          throw new InvalidCaptChaInputException(
              "WARNING: The string you entered does not match"
                  + " with what is shown in the image. Please try again.");
} else {
}        request.getSession().removeAttribute(Captcha.NAME);
      return null;
  }
 

import nl.captcha.Captcha; //导入依赖的package包/类
/**
 * Creates a {@link Captcha} and stores it in the session.
 *
 * @param width  the width of the image
 * @param height the height of the image
 * @return {@link BufferedImage} containing the captcha image
 */
public BufferedImage createCaptcha(int width, int height)
{
	Captcha captcha = new Captcha.Builder(width, height).addText()
														.addBackground(new GradiatedBackgroundProducer())
														.gimp()
														.addNoise()
														.addBorder()
														.build();
	session.setAttribute(Captcha.NAME, captcha);
	return captcha.getImage();
}