In addition to that it is a slick CAPCHA implementation as well, that you can incorporate freely into your web applications. There are APIs available for various languages including Java, Ruby and Python.
For my Struts 2 + Spring project I am using reCAPTCHA for the user registration page. The user fills out the registration but before s(he) submits the form a reCAPCHA form field has to be filled out, which means recognizing 2 words that are part of an image and retyping those two words into a form field. Upon form submission, code in my Struts 2 action calls the reCAPCHA Java API and validates the two words that were previously entered by the user.
Setting everything up has been easy and involves the following steps:
- Signup for a reCAPTCHA account and generate the necessary keys for your site (similar to setting up Google Maps)
- Add the recaptcha4j library to your project
- Add some Javascript code to your JSP
- Define the main recaptcha4j bean in your Spring ApplicationContext.xml file
- Configure your Struts 2 Actions to process and validate the reCAPCHA form data
<bean id="reCaptcha" class="net.tanesha.recaptcha.ReCaptchaImpl">
<property name="privateKey" value="your private key"/>
<property name="publicKey" value="your public key"/>
<property name="recaptchaServer" value="http://api.recaptcha.net"/>
<!-- For SSL use:
<property name="recaptchaServer" value="https://api-secure.recaptcha.net"/> -->
<property name="includeNoscript" value="false"/>
</bean>
In your jsp:
Setup your Struts 2 action to process two form parameters:
- recaptcha_challenge_field
- recaptcha_response_field
Then in your actual action code you validate those 2 token by calling:
public class SignupAction {
private User user;
private String recaptcha_challenge_field;
private String recaptcha_response_field;
private @Autowired ReCaptcha reCaptcha;
public String execute() {
ReCaptchaResponse reCaptchaResponse = reCaptcha.checkAnswer(
ServletActionContext.getRequest().getRemoteHost(),
recaptcha_challenge_field,
recaptcha_response_field);
if (!reCaptchaResponse.isValid()) {
addActionError("Not a good CAPTCHA.");
return INPUT;
}
...process the user registration form etc.
return SUCCESS;
}
...your setters
}
That's it. These should be all the basic steps necessary to get you going.
Here are some further resources:
http://wheelersoftware.com/articles/recaptcha-java-2.html
http://tanesha.net/projects/recaptcha4j/
http://recaptcha.net/apidocs/captcha/
