org.loklak.api.server.GraphServlet.java Source code

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Here is the source code for org.loklak.api.server.GraphServlet.java

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/**
 *  GraphServlet
 *  Copyright 14.10.2015 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.server;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.loklak.harvester.TwitterAPI;
import org.loklak.http.RemoteAccess;

import twitter4j.TwitterException;

import com.fasterxml.jackson.databind.ObjectMapper;

public class GraphServlet extends HttpServlet {

    private static final long serialVersionUID = 8578478303032749879L;

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        RemoteAccess.Post post = RemoteAccess.evaluate(request);

        // manage DoS
        if (post.isDoS_blackout()) {
            response.sendError(503, "your request frequency is too high");
            return;
        }

        // parameters
        String callback = post.get("callback", "");
        boolean jsonp = callback != null && callback.length() > 0;
        boolean minified = post.get("minified", false);
        String[] screen_names = post.get("screen_name", "").split(",");
        String followers = screen_names.length == 1 ? post.get("followers", "0") : "0";
        String following = screen_names.length == 1 ? post.get("following", "0") : "0";
        int maxFollowers = Integer.parseInt(followers);
        int maxFollowing = Integer.parseInt(following);

        List<Map<String, Object>> twitterUserEntries = new ArrayList<>();
        for (String screen_name : screen_names) {
            try {
                Map<String, Object> twitterUserEntry = TwitterAPI.getUser(screen_name, false);
                if (twitterUserEntry != null)
                    twitterUserEntries.add(twitterUserEntry);
            } catch (TwitterException e) {
            }
        }
        Map<String, Object> topology = null;
        try {
            topology = TwitterAPI.getNetwork(screen_names[0], maxFollowers, maxFollowing);
        } catch (TwitterException e) {
        }

        post.setResponse(response, "application/javascript");

        // generate json
        Map<String, Object> m = new LinkedHashMap<>();
        m.put("edges", post.getClientHost());

        if (twitterUserEntries.size() == 1)
            m.put("user", twitterUserEntries.iterator().next());
        if (twitterUserEntries.size() > 1)
            m.put("users", twitterUserEntries);
        if (topology != null)
            m.put("topology", topology);

        // write json
        FileHandler.setCaching(response, 10);
        response.setCharacterEncoding("UTF-8");
        PrintWriter sos = response.getWriter();
        if (jsonp)
            sos.print(callback + "(");
        sos.print((minified ? new ObjectMapper().writer() : new ObjectMapper().writerWithDefaultPrettyPrinter())
                .writeValueAsString(m));
        if (jsonp)
            sos.println(");");
        sos.println();
        post.finalize();
    }
}