/**
* ProxyServlet
* Copyright 12.06.2015 by Michael Peter Christen, @0rb1t3r
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package org.loklak.api.cms;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.util.log.Log;
import org.json.JSONObject;
import org.loklak.data.DAO;
import org.loklak.data.IndexEntry;
import org.loklak.harvester.TwitterAPI;
import org.loklak.http.ClientConnection;
import org.loklak.http.RemoteAccess;
import org.loklak.objects.UserEntry;
import org.loklak.server.Query;
import org.loklak.tools.CacheMap;
import twitter4j.TwitterException;
public class ProxyServlet extends HttpServlet {
private static final long serialVersionUID = -9112326722297824443L;
private final static CacheMap<String, byte[]> cache = new CacheMap<>(1000);
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Query post = RemoteAccess.evaluate(request);
if (post.isDoS_blackout()) {response.sendError(503, "your request frequency is too high"); return;} // DoS protection
process(request, response, post);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Query post = RemoteAccess.evaluate(request);
if (post.isDoS_blackout()) {response.sendError(503, "your request frequency is too high"); return;} // DoS protection
post.initPOST(RemoteAccess.getPostMap(request));
process(request, response, post);
}
// http://localhost:9000/api/proxy.png?screen_name=loklak_app&url=https://pbs.twimg.com/profile_images/577512240640733184/fizL4YIn_bigger.png
protected void process(HttpServletRequest request, HttpServletResponse response, Query post) throws ServletException, IOException {
// parse arguments
String url = post.get("url", "");
String screen_name = post.get("screen_name", "");
DAO.log("PROXY: called with screen_name=" + screen_name + ", url=" + url);
if (screen_name.length() == 0 && (url.length() == 0 || screen_name.indexOf("twimg.com") < 0)) {
response.sendError(503, "either attributes url or screen_name or both must be submitted"); return;
}
byte[] buffer = url.length() == 0 ? null : cache.get(url);
if (buffer != null) DAO.log("PROXY: got url=" + url + " content from ram cache!");
UserEntry user = null;
if (buffer == null && screen_name.length() > 0) {
if (buffer == null && (url.length() == 0 || isProfileImage(url))) {
// try to read it from the user profiles
user = DAO.searchLocalUserByScreenName(screen_name);
if (user != null) {
buffer = user.getProfileImage();
if (buffer != null) DAO.log("PROXY: got url=" + url + " content from user profile bas64 cache!");
if (url.length() == 0) url = user.getProfileImageUrl();
cache.put(user.getProfileImageUrl(), buffer);
}
}
}
if (buffer == null && url.length() > 0) {
// try to download the image
buffer = ClientConnection.download(url);
String newUrl = user == null ? null : user.getProfileImageUrl();
if (buffer != null) {
DAO.log("PROXY: downloaded given url=" + url + " successfully!");
} else if (newUrl != null && !newUrl.equalsIgnoreCase(url)) {
// if this fails, then check if the stored url is different.
// That may happen because new user avatar images get new urls
buffer = ClientConnection.download(newUrl);
if (buffer != null) DAO.log("PROXY: downloaded url=" + url + " from old user setting successfully!");
}
if (buffer == null) {
// ask the Twitter API for new user data
try {
JSONObject usermap = TwitterAPI.getUser(screen_name, true);
newUrl = usermap.has("profile_image_url") ? (String) usermap.get("profile_image_url") : null;
if (newUrl != null && newUrl.length() > 0 && !newUrl.startsWith("http:") && usermap.has("profile_image_url_https")) newUrl = (String) usermap.get("profile_image_url_https");
if (newUrl != null && newUrl.length() > 0) buffer = ClientConnection.download(newUrl);
if (buffer != null) DAO.log("PROXY: downloaded url=" + url + " from recently downloaded user setting successfully!");
} catch (TwitterException e) {
DAO.log("ProxyServlet: call to twitter api failed: " + e.getMessage());
}
}
if (buffer != null) {
// write the buffer
if (user != null) {
user.setProfileImageUrl(newUrl);
user.setProfileImage(buffer);
try {
// record user into search index
DAO.users.writeEntry(new IndexEntry<UserEntry>(user.getScreenName(), user.getType(), user));
} catch (IOException e) {
Log.getLog().warn(e);
}
if (!cache.full()) cache.put(url, buffer);
} else {
cache.put(url, buffer);
}
}
}
if (buffer == null) {
if (screen_name.length() == 0) {
response.sendError(503, "url cannot be loaded"); return;
}
if (url.length() == 0) {
response.sendError(503, "user cannot be found"); return;
}
response.sendError(503, "url cannot be loaded and user cannot be found"); return;
}
if (url.endsWith(".png") || (url.length() == 0 && request.getServletPath().endsWith(".png"))) post.setResponse(response, "image/png");
else if (url.endsWith(".gif") || (url.length() == 0 && request.getServletPath().endsWith(".gif"))) post.setResponse(response, "image/gif");
else if (url.endsWith(".jpg") || url.endsWith(".jpeg") || (url.length() == 0 && request.getServletPath().endsWith(".jpg"))) post.setResponse(response, "image/jpeg");
else post.setResponse(response, "application/octet-stream");
ServletOutputStream sos = response.getOutputStream();
sos.write(buffer);
post.finalize();
}
private boolean isProfileImage(String url) {
return url.indexOf("pbs.twimg.com/profile_images") > 0 && url.endsWith("_bigger.png");
}
}