/**
* Copyright 2010 Daniel Guermeur and Amy Unruh
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* See http://connectrapp.appspot.com/ for a demo, and links to more information
* about this app and the book that it accompanies.
*/
package com.metadot.book.connectr.server.servlets;
import java.io.IOException;
import java.util.Enumeration;
import java.util.logging.Logger;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.JSONException;
import org.json.JSONObject;
import com.metadot.book.connectr.server.AppLib;
import com.metadot.book.connectr.server.LoginHelper;
import com.metadot.book.connectr.server.domain.UserAccount;
import com.metadot.book.connectr.server.utils.AuthenticationProvider;
import com.metadot.book.connectr.server.utils.UrlFetcher;
public class LoginFacebookServlet extends LoginSuperServlet {
private static final long serialVersionUID = -1187933703374946249L;
private static Logger log = Logger.getLogger(LoginFacebookServlet.class.getName());
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
String callbackURL = null, clientSecret = null, appId = null;
appId = AuthenticationProvider.getProp("fb_app_id");
clientSecret = AuthenticationProvider.getProp("fb_secret");
if(appId == null || clientSecret == null){
response.setContentType("text/html");
response.getWriter().print(AppLib.INFONOTFOUND);
return;
}
callbackURL = AuthenticationProvider.getProp("fb_callback_url");
String code = request.getParameter("code");
if (code != null && !code.isEmpty()) {
// Facebook authentication has been done and Facebook is calling us back here:
String keyNValues = getParams(request);
log.info("==== STEP 2/1: got params=" + keyNValues);
log.info("==== STEP 2/2: got code=" + code);
/*
* Save code in session
*/
request.getSession().setAttribute("facebook_code", code);
/*
* Get access token
*/
String tokenURL = "https://graph.facebook.com/oauth/access_token" + "?client_id=" + appId + "&redirect_uri="
+ callbackURL + "&client_secret=" + clientSecret + "&code=" + code;
log.info("requesting access token url=" + tokenURL);
String resp = UrlFetcher.get(tokenURL);
log.info("Response = " + resp);
int beginIndex = "access_token=".length();
String token = resp.substring(beginIndex);
log.info("Extracted token = " + token);
/*
* Get user info
*/
String url = "https://graph.facebook.com/me?access_token=" + token;
log.info("requesting user info: " + url);
resp = UrlFetcher.get(url);
log.info("Response: " + resp);
UserAccount connectr = extractUserInfo(resp);
connectr = new LoginHelper().loginStarts(request.getSession(), connectr);
log.info("User id is logged in:" + connectr.getId().toString());
/*
* All done. Let's go home.
*/
response.sendRedirect(LoginHelper.getApplitionURL(request));
} else {
// Redirect to Facebook login page
log.info("Starting FB authentication appid: " + appId + " - callback: " + callbackURL);
String fbLoginPage = "https://graph.facebook.com/oauth/authorize"
+ "?client_id=" + appId
+ "&redirect_uri=" + callbackURL;
response.sendRedirect(fbLoginPage);
}
}
private UserAccount extractUserInfo(String resp) {
log.info("Extracting user info");
JSONObject j;
UserAccount u = null;
try {
j = new JSONObject(resp);
String first = j.getString("first_name");
String last = j.getString("last_name");
String id = j.getString("id");
log.info("User info from JSON: " + first + " " + last + " id = " + id);
u = new UserAccount(id, AuthenticationProvider.FACEBOOK);
u.setName(first + " " + last);
} catch (JSONException e) {
e.printStackTrace();
}
return u;
}
private String getParams(HttpServletRequest request) {
Enumeration<?> all = request.getParameterNames();
String msg = "";
while (all.hasMoreElements()) {
String key = (String) all.nextElement();
msg += key + " = " + request.getParameter(key) + "<br/>\n";
}
return msg;
}
}