package com.google.sps.servlets;

import com.google.appengine.api.users.UserServiceFactory;
import com.google.gson.Gson;
import com.google.sps.data.Event;
import com.google.sps.data.User;
import com.google.sps.utilities.CommonUtils;
import com.google.sps.utilities.GetLabelCategories;
import com.google.sps.utilities.EventRanker;
import com.google.sps.utilities.SpannerTasks;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.javatuples.Pair;

@WebServlet("/event-ranker")
public class EventRankerServlet extends HttpServlet {
  private static String EVENTS_KEY = "events";

  /** Returns events in order of relevance */
  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String email = UserServiceFactory.getUserService().getCurrentUser().getEmail();
    Optional<User> userOptional = SpannerTasks.shallowReadUserFromEmail(email);
    User user;
    if (userOptional.isPresent()) {
      ArrayList<String> eventIds = new ArrayList<>();
      String[] eventIdsParameter = (request.getParameter(EVENTS_KEY).split(","));
      for (String event : eventIdsParameter) {
          eventIds.add(event.replace("\"", "").replace("[", "").replace("]", ""));
      }
      user = userOptional.get();
      List<Event> rankedRelevantEvents = EventRanker.rankEvents(user, SpannerTasks.getEventsFromIds(eventIds));
      response.setContentType("application/json;");
      response.getWriter().println(CommonUtils.convertToJson(rankedRelevantEvents));
    } else {
      response.sendError(HttpServletResponse.SC_BAD_REQUEST, "User not found.");
    }
  }
}


package com.google.sps.servlets;

import com.google.appengine.api.users.UserServiceFactory;
import com.google.gson.Gson;
import com.google.sps.data.Event;
import com.google.sps.data.User;
import com.google.sps.utilities.CommonUtils;
import com.google.sps.utilities.GetLabelCategories;
import com.google.sps.utilities.EventRanker;
import com.google.sps.utilities.SpannerTasks;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.javatuples.Pair;

@WebServlet("/event-ranker")
public class EventRankerServlet extends HttpServlet {
  private static String EVENTS_KEY = "events";

  /** Returns events in order of relevance */
  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String email = UserServiceFactory.getUserService().getCurrentUser().getEmail();
    Optional<User> userOptional = SpannerTasks.shallowReadUserFromEmail(email);
    User user;
    if (userOptional.isPresent()) {
      ArrayList<String> eventIds = new ArrayList<>();
      String[] eventIdsParameter = (request.getParameter(EVENTS_KEY).split(","));
      for (String event : eventIdsParameter) {
          eventIds.add(event.replaceAll("\"|\\[|\\]", ""));
      }
      user = userOptional.get();
      List<Event> rankedRelevantEvents = EventRanker.rankEvents(user, SpannerTasks.getEventsFromIds(eventIds));
      response.setContentType("application/json;");
      response.getWriter().println(CommonUtils.convertToJson(rankedRelevantEvents));
    } else {
      response.sendError(HttpServletResponse.SC_BAD_REQUEST, "User not found.");
    }
  }
}


Change list to pair acceptance for servlet