ReCaptchaService.java

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class ReCaptchaService {

	private static final String URL = "https://www.google.com/recaptcha/api/siteverify?secret={secret}&response={response}&remoteip={remoteip}";

	private RestTemplate restTemplate = new RestTemplate();

	@Value("${reCaptcha.secret}")
	private String secret;

	public boolean verify(HttpServletRequest request) {

		String gRecaptchaResponse = request.getParameter("g-recaptcha-response");
		String remoteAddress = request.getRemoteAddr();

		Map<String, String> uriVariable = new HashMap<>();
		uriVariable.put("secret", secret);
		uriVariable.put("response", gRecaptchaResponse);
		uriVariable.put("remoteip", remoteAddress);

		ReCaptchaResponse response = restTemplate.postForObject(URL, null, ReCaptchaResponse.class, uriVariable);

		return response.isSuccess();
	}

	static class ReCaptchaResponse {

		public boolean success;

		public boolean isSuccess() {
			return success;
		}

		public void setSuccess(boolean success) {
			this.success = success;
		}
	}

}