D-Net

package eu.dnetlib.openaire.user.utils;

import org.apache.log4j.Logger;

import javax.json.Json;

import javax.json.JsonObject;

import javax.json.JsonReader;

import javax.net.ssl.HttpsURLConnection;

import java.io.BufferedReader;

import java.io.DataOutputStream;

import java.io.InputStreamReader;

import java.io.StringReader;

import java.net.URL;

public class VerifyRecaptcha {

    public static final String url = "https://www.google.com/recaptcha/api/siteverify";

    //private final static String USER_AGENT = "Mozilla/5.0";

    private static Logger logger = Logger.getLogger(VerifyRecaptcha.class);

    public static boolean verify(String gRecaptchaResponse, String secret) {

        logger.debug("Recaptch secret " + secret);

        logger.debug("response " + gRecaptchaResponse);

        if (gRecaptchaResponse == null || "".equals(gRecaptchaResponse)) {

            return false;

        }

        try{

            URL obj = new URL(url);

            HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

            // add reuqest header

            con.setRequestMethod("POST");

            //con.setRequestProperty("User-Agent", USER_AGENT);

            con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

            String postParams = "secret=" + secret + "&response="

                    + gRecaptchaResponse;

            // Send post request

            con.setDoOutput(true);

            DataOutputStream wr = new DataOutputStream(con.getOutputStream());

            wr.writeBytes(postParams);

            wr.flush();

            wr.close();

            int responseCode = con.getResponseCode();

            logger.debug("\nSending 'POST' request to URL : " + url);

            logger.debug("Post parameters : " + postParams);

            logger.info("recaptcha response Code : " + responseCode);

            BufferedReader in = new BufferedReader(new InputStreamReader(

                    con.getInputStream()));

            String inputLine;

            StringBuffer response = new StringBuffer();

            while ((inputLine = in.readLine()) != null) {

                response.append(inputLine);

            }

            in.close();

            // print result

            logger.debug(response.toString());

            //parse JSON response and return 'success' value

            JsonReader jsonReader = Json.createReader(new StringReader(response.toString()));

            JsonObject jsonObject = jsonReader.readObject();

            jsonReader.close();

            return jsonObject.getBoolean("success");

        } catch(Exception e){

            logger.error("Error validating recaptcha");

            return false;

        }

    }

}