Adding Captcha Fields

To use captcha validation support in the actions, the checkCaptcha parameter needs to be set to true in the Struts action configuration. When this parameter is set, the action enforces captcha validation. For example, if we want to add captcha validation to the /blog/add action which is an instance of the class com.ndc.usercontent.struts.actions.save.SaveArticle, we need the following configuration.

<action path="/blog/add"
			  name="articleForm"
  			parameter="articleType=blog;checkCaptcha=true"
	  		type="com.ndc.usercontent.struts.actions.save.SaveArticle">
        <!-- Other action configuration stuff -->
</action>

Once the above configuration is in place, we can write JSP segment as part of an HTML form to show the captcha challenge interface. For example, we want to add a captcha field to the the /blog/add action . To do this, we need to add the following JSP segment in the HTML form that will allow a user to create a blog.

• For ReCaptcha

  <html:form action="/blog/add">
    <!-- JSP code to render the form properties related to creating a blog -->
  
    <div class="captcha">
      <captcha:recaptchaHTML theme="red" lang="en"/>
    </div>
  
    <!-- The rest of the JSP code to render the form properties related to
         creating a blog goes here. -->
  </html:form>
  

  <captcha:recaptchaHTML/> tag prints the HTML fragment to show ReCaptcha interface

• For JCaptcha

  <html:form action="/blog/add">
    <!-- JSP code to render the form properties related to creating a blog -->
  
    <div class="captcha">
      <label for="jcaptcha_response">Verification code: </label>
      <input id="jcaptcha_response" type="text" name="jcaptcha_response" /><br/>
      <html:image page="/jcaptcha.do"/>
    </div>
  
    <!-- The rest of the JSP code to render the form properties related to
         creating a blog goes here. -->
  </html:form>
  

  Note the input element named jcaptcha_response. This field should contain the code displayed in the captcha image. The tag <html:image page="/jcaptcha.do"/> creates the HTML element img with appropriate image source URL, which in turn pulls the image from the /jcaptcha action.

When the user's input captcha code is wrong, the action will direct the user to the configured error page (which in common case is the same page where the user is filling the form). Have a look at Creating Articles to get an overview on how to configure the error URL. Here is the JSP fragment to show captcha error in error page:

<logic:messagesPresent message="true" property="CAPTCHA">
  <p class="fieldError">
    <html:messages id="error" message="true" bundle="Validation" property="CAPTCHA">
      <bean:write name="error"/><br />
    </html:messages>
  </p>
</logic:messagesPresent>

The following VCE Struts actions come with built-in support for captcha verification:

• com.ndc.usercontent.struts.actions.save.SaveArticle

• com.ndc.usercontent.struts.actions.save.SaveGroupProfile

• com.ndc.usercontent.struts.actions.save.SaveUserProfile

Captcha support can be used for the Forum actions in a similar way, if you have configured properly as stated in VCE Captcha Support for Forum

If you want to use captcha provider support for other actions, you can write a generic servlet filter through which the request that requires captcha verification must go through.