Kaptcha

kaptcha - A kaptcha generation engine clone of http://code.google.com/p/kaptcha/.

Goals

• Make it Maven based
• Allow use it from Spring

I've tried to use:

• JCaptcha (http://jcaptcha.sourceforge.net/)

  • Bad community responds (bad API).

• SimpleCaptcha (http://simplecaptcha.sourceforge.net/)

  • Not maven based
  • Binary based (imaging.jar represents jhlabs of 2000, Internet gives me only latest com.jhlabs.filters:2.0.235 version)

• ReCaptcha (http://www.google.com/recaptcha)

  • Hard to read

and decided to make my own fork...

Central Maven Repo

  <dependencies>
    <dependency>
      <groupId>com.github.axet</groupId>
      <artifactId>kaptcha</artifactId>
      <version>0.0.6</version>
    </dependency>
  </dependencies>

Example

package com.example.controller;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.servlet.ModelAndView;

import com.google.code.kaptcha.servlet.KaptchaExtend;

@Controller
public class RegisterKaptchaController extends KaptchaExtend {

    @RequestMapping(value = "/captcha.jpg", method = RequestMethod.GET)
    public void captcha(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.captcha(req, resp);
    }

    @RequestMapping(value = "/register", method = RequestMethod.GET)
    public ModelAndView registerGet(@RequestParam(value = "error", required = false) boolean failed,
            HttpServletRequest request) {
        ModelAndView model = new ModelAndView("register-get");
        
        //
        // model MUST contain HTML with <img src="/captcha.jpg" /> tag
        //
        
        return model;
    }

    @RequestMapping(value = "/register", method = RequestMethod.POST)
    public ModelAndView registerPost(@RequestParam(value = "email", required = true) String email,
            @RequestParam(value = "password", required = true) String password, HttpServletRequest request) {
        ModelAndView model = new ModelAndView("register-post");

        if (email.isEmpty())
            throw new RuntimeException("email empty");

        if (password.isEmpty())
            throw new RuntimeException("empty password");

        String captcha = request.getParameter("captcha");

        if (!captcha.equals(getGeneratedKey(request)))
            throw new RuntimeException("bad captcha");

        //
        // eveyting is ok. proceed with your user registration / login process.
        //

        return model;
    }

}