BotDetect Struts CAPTCHA Integration Quickstart

Unlike Recaptcha the Stalker -- BotDetect CAPTCHA works in China! Licensable source-code; self-hosted -- doesn't stalk -- nor does it slurp your form-data! Think: GDPR & LGPD!

1. Add BotDetect Java CAPTCHA Library Dependency

Install BotDetect Java CAPTCHA dependencies

The free version Maven artifacts are available from our public repository; while the enterprise version jars are available in the root folder of the enterprise version's archive.

To reference the BotDetect dependency from our public repository, the repository itself has to be declared first -- add the highlighted lines to your app's pom.xml file:

<repository>
  <id>captcha</id>
  <name>BotDetect Captcha Repository</name>
  <url>https://git.captcha.com/botdetect-java-captcha.git/blob_plain/HEAD:/</url>
</repository>

Then, in the same file, declare the BotDetect dependency, too:

<dependency>
  <groupId>com.captcha</groupId>
  <artifactId>botdetect-jsp20</artifactId>
  <version>4.0.beta3.7</version>
</dependency>

2. Show a CAPTCHA Challenge on the Form

On the very top of the source file for the web form you want to protect against bots, put BotDetect taglib declaration:

<%@taglib prefix="botDetect" uri="https://captcha.com/java/jsp"%>

To render Captcha in the form, add the following within <form> you want to protect against bots:

<!-- Adding BotDetect Captcha to the page -->
<botDetect:captcha id="exampleCaptcha" userInputID="captchaCode"/>

<s:textfield name="captchaCode" id="captchaCode"/>
<s:submit name="submit" label="Submit" id="submit"/>

And you also need to add exclude directive for CaptchaServlet to Struts 2 filter by adding the following in your struts.xml configuration file:

<constant name="struts.action.excludePattern" value="/botdetectcaptcha"/>

3. Check User Input During Form Submission

When the form is submitted, the Captcha validation result must be checked in Struts Action:

[...]
public class BasicCaptchaAction extends ActionSupport {
  
  private String captchaCode;

  public String getCaptchaCode() {
    return captchaCode;
  }

  public void setCaptchaCode(String captchaCode) {
    this.captchaCode = captchaCode;
  }
  
  public String execute() {
    return SUCCESS;
  }
  
  public void validate() {
    Captcha captcha = Captcha.load(ServletActionContext.getRequest(), "exampleCaptcha");
    boolean isHuman = captcha.validate(captchaCode);
    if (!isHuman) {
      addFieldError("captchaCode", "Incorrect code");
    }
  }
}

4. Configure your Application

Update your application configuration (web.xml) file.

<servlet>
  <servlet-name>BotDetect Captcha</servlet-name>
  <servlet-class>com.captcha.botdetect.web.servlet.CaptchaServlet</servlet-class>
</servlet>
<servlet-mapping>
  <servlet-name>BotDetect Captcha</servlet-name>
  <url-pattern>/botdetectcaptcha</url-pattern>
</servlet-mapping>

In-Depth Struts CAPTCHA Instructions and Explanations

Detailed Struts Captcha instructions and explanations can be found in the Struts Captcha integration how to guide.


Please Note

BotDetect Java Captcha Library v4.0.Beta3.7 is an in-progress port of BotDetect 4 Captcha, and we need you to guide our efforts towards a polished product. Please let us know if you encounter any bugs, implementation issues, or a usage scenario you would like to discuss.