com.google.sampling.experiential.server.ExperimentServlet.java Source code

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/*
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * 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.
 */
package com.google.sampling.experiential.server;

import java.io.IOException;
import java.util.List;
import java.util.logging.Logger;

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

import org.joda.time.DateTimeZone;

import com.google.appengine.api.users.User;
import com.google.common.base.Strings;
import com.google.common.collect.Lists;
import com.pacoapp.paco.shared.comm.Outcome;

/**
 * Servlet that answers requests for experiments.
 *
 * Only used by the Android client to get the current list of experiments.
 *
 * @author Bob Evans
 *
 */
@SuppressWarnings("serial")
public class ExperimentServlet extends HttpServlet {

    private static final int EXPERIMENT_LIMIT_MAX = 50;
    public static final Logger log = Logger.getLogger(ExperimentServlet.class.getName());
    public static final String DEV_HOST = "<Your machine name here>";

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("application/json;charset=UTF-8");

        User user = AuthUtil.getWhoFromLogin();

        if (user == null) {
            AuthUtil.redirectUserToLogin(req, resp);
        } else {
            DateTimeZone timezone = TimeUtil.getTimeZoneForClient(req);
            log.info("Timezone is computed to be: " + timezone.toString());
            RequestProcessorUtil.logPacoClientVersion(req);

            String email = AuthUtil.getEmailOfUser(req, user);

            String experimentsPublishedToMeParam = req.getParameter("mine");
            String selectedExperimentsParam = req.getParameter("id");
            String experimentsPublishedPubliclyParam = req.getParameter("public");
            String experimentsAdministeredByUserParam = req.getParameter("admin");
            String experimentsJoinedByMeParam = req.getParameter("joined");
            String experimentsPopularParam = req.getParameter("popular");
            String experimentsNewParam = req.getParameter("new");

            String pacoProtocol = RequestProcessorUtil.getPacoProtocolVersionAsStr(req);

            // String offset = req.getParameter("offset");
            String limitStr = req.getParameter("limit");
            Integer limit = null;
            if (limitStr != null) {
                try {
                    limit = Integer.parseInt(limitStr);
                } catch (NumberFormatException e) {
                }
            }
            // if (limit != null && (limit <= 0 || limit >= EXPERIMENT_LIMIT_MAX)) {
            // throw new IllegalArgumentException("Invalid limit. must be greater
            // than 0 and less than or equal to 50");
            // }
            String cursor = req.getParameter("cursor");

            String experimentsJson = null;
            ExperimentServletHandler handler;
            if (experimentsPublishedToMeParam != null) {
                handler = new ExperimentServletExperimentsForMeLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol);
            } else if (selectedExperimentsParam != null) {
                handler = new ExperimentServletSelectedExperimentsFullLoadHandler(email, timezone,
                        selectedExperimentsParam, pacoProtocol);
            } else if (experimentsPublishedPubliclyParam != null) {
                handler = new ExperimentServletExperimentsShortPublicLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol);
            } /*
               * else if (experimentsAdministeredByUserParam != null &&
               * experimentsJoinedByMeParam != null) { handler = new
               * ExperimentServletAdminAndJoinedExperimentsShortLoadHandler(email,
               * timezone, limit, cursor, pacoProtocol); }
               */else if (experimentsJoinedByMeParam != null) {
                handler = new ExperimentServletJoinedExperimentsShortLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol);
            } else if (experimentsAdministeredByUserParam != null) {
                String sortColumn = req.getParameter("sortColumn");
                String sortOrder = req.getParameter("sortOrder");
                handler = new ExperimentServletAdminExperimentsFullLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol, sortColumn, sortOrder);
            } else if (experimentsPopularParam != null) {
                handler = new ExperimentServletExperimentsPopularLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol);
            } else if (experimentsNewParam != null) {
                handler = new ExperimentServletExperimentsNewLoadHandler(email, timezone, limit, cursor,
                        pacoProtocol);
            } else {
                handler = null; // new
                                // ExperimentServletAllExperimentsFullLoadHandler(email,
                                // timezone, limit, cursor, pacoProtocol);
            }
            if (handler != null) {
                log.info("Loading experiments...");
                experimentsJson = handler.performLoad();
                resp.getWriter().println(scriptBust(experimentsJson));
            } else {
                resp.getWriter().println(scriptBust("Unrecognized parameters!"));
            }

        }
    }

    private String scriptBust(String experimentsJson) {
        // TODO add scriptbusting prefix to this and client code.
        return experimentsJson;
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("application/json;charset=UTF-8");
        User user = AuthUtil.getWhoFromLogin();
        if (user == null) {
            AuthUtil.redirectUserToLogin(req, resp);
        } else {
            DateTimeZone timezone = TimeUtil.getTimeZoneForClient(req);
            RequestProcessorUtil.logPacoClientVersion(req);
            String email = AuthUtil.getEmailOfUser(req, user);

            String delete = req.getParameter("delete");
            if (!Strings.isNullOrEmpty(delete)) {
                String selectedExperimentsParam = req.getParameter("id");
                if (Strings.isNullOrEmpty(selectedExperimentsParam)) {
                    List<Outcome> outcomes = createErrorOutcome("No experiment ids specified for deletion");
                    resp.getWriter().println(ExperimentJsonUploadProcessor.toJson(outcomes));
                } else {
                    resp.getWriter().println(ExperimentJsonUploadProcessor
                            .toJson(deleteExperiments(email, selectedExperimentsParam)));
                }
            } else {
                readExperimentDefinitions(req, resp);
            }
        }
    }

    public List<Outcome> createErrorOutcome(String msg) {
        Outcome outcome = new Outcome(0, msg);
        List<Outcome> outcomes = Lists.newArrayList(outcome);
        return outcomes;
    }

    private List<Outcome> deleteExperiments(String email, String selectedExperimentsParam) {
        ExperimentService expService = ExperimentServiceFactory.getExperimentService();
        List<Long> experimentIds = ExperimentServletSelectedExperimentsFullLoadHandler
                .parseExperimentIds(selectedExperimentsParam);
        if (experimentIds.isEmpty()) {
            return createErrorOutcome("No experiment ids specified for deletion");
        }
        Outcome outcome = new Outcome();
        List<Outcome> outcomeList = Lists.newArrayList();
        outcomeList.add(outcome);
        try {
            final Boolean deleteExperimentsResult = expService.deleteExperiments(experimentIds, email);
            if (!deleteExperimentsResult) {
                outcome.setError("Could not delete experiments. Rolled back.");
            }
        } catch (Exception e) {
            outcome.setError("Could not delete experiments. Rolled back. Error: " + e.getMessage());
        }

        return outcomeList;
    }

    private void readExperimentDefinitions(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        String postBodyString;
        try {
            postBodyString = org.apache.commons.io.IOUtils.toString(req.getInputStream(), "UTF-8");
        } catch (IOException e) {
            final String msg = "IO Exception reading post data stream: " + e.getMessage();
            log.info(msg);
            List<Outcome> outcomes = createErrorOutcome(msg);
            resp.getWriter().println(ExperimentJsonUploadProcessor.toJson(outcomes));
            return;
        }

        if (postBodyString.equals("")) {
            List<Outcome> outcomes = createErrorOutcome("Empty Post body");
            resp.getWriter().println(ExperimentJsonUploadProcessor.toJson(outcomes));
            return;
        }

        String appIdHeader = req.getHeader("http.useragent");
        String pacoVersion = req.getHeader("paco.version");
        log.info("Paco version = " + pacoVersion);
        DateTimeZone timezone = TimeUtil.getTimeZoneForClient(req);
        final User whoFromLogin = AuthUtil.getWhoFromLogin();
        String results = ExperimentJsonUploadProcessor.create().processJsonExperiments(postBodyString, whoFromLogin,
                appIdHeader, pacoVersion, timezone);
        resp.getWriter().write(results);
    }
}