EU CAPTCHA for Java

Frequently Asked Questions

• How do I verify a CAPTCHA token in Java?

  Add the EU CAPTCHA Java client library to your project via Maven or Gradle. In your controller or request handler, read the eu-captcha-response parameter from the submitted form data, then call the client's verification method with your secret key and the token. Process the request only if the API confirms a valid human interaction.

• Does EU CAPTCHA work with Spring Boot?

  Yes. EU CAPTCHA integrates naturally with Spring Boot. Add the Java client as a Spring bean in a @Configuration class and inject it into your @Controller or @RestController. In your @PostMapping handler, read the eu-captcha-response from the @RequestParam or request body, call the verification method, and return an appropriate response based on the result.

• Is there an official Java client library for EU CAPTCHA?

  Yes. EU CAPTCHA provides an official Java client generated from the OpenAPI specification. Add it to your Maven pom.xml or Gradle build.gradle. The library supports Java 8 and later and provides a typed client that handles the HTTP call, authentication, and JSON response parsing.

• How do I add the EU CAPTCHA Java dependency to Maven or Gradle?

  For Maven, add the EU CAPTCHA client artifact to the dependencies section of your pom.xml. For Gradle, add it to the dependencies block in your build.gradle or build.gradle.kts file. Consult the EU CAPTCHA documentation for the current artifact coordinates and version.

• Can I use EU CAPTCHA with Jakarta EE, Quarkus, or Micronaut?

  Yes. The EU CAPTCHA Java client is a standard Java library that works in any JVM environment. For Jakarta EE, use it in a CDI bean or servlet filter. For Quarkus, inject it as a CDI bean and call the verification method in your REST endpoint. For Micronaut, register it as a singleton bean and inject it into your controller.

• Can I create a Spring interceptor or filter for EU CAPTCHA verification?

  Yes. You can implement a HandlerInterceptor or OncePerRequestFilter in Spring that performs the EU CAPTCHA token verification before your controller handler runs. This allows you to apply bot protection to multiple endpoints without duplicating the verification logic in each controller method, keeping your codebase clean and consistent.

• Is EU CAPTCHA GDPR compliant for Java web applications?

  Yes. EU CAPTCHA is operated by an EU-based company, is hosted entirely in Germany, and does not rely on US cloud providers or infrastructure subject to US surveillance laws. The service processes only the data necessary to provide and verify the CAPTCHA (such as IP address and technical browser or device information) in line with the requirements of the GDPR. Your organization remains responsible for providing transparent privacy information, selecting an appropriate legal basis, and obtaining any required consent for your specific Java implementation. This information does not constitute legal advice; please consult your legal counsel for an assessment of your individual case.