UserSessionDao.java

/*
 * Copyright 2013 ArcBees Inc.
 *
 * 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.gwtplatform.carstore.server.dao;

import java.util.Calendar;
import java.util.Date;
import java.util.UUID;
import java.util.logging.Logger;

import javax.inject.Inject;

import com.googlecode.objectify.Key;
import com.gwtplatform.carstore.server.dao.domain.User;
import com.gwtplatform.carstore.server.dao.domain.UserSession;
import com.gwtplatform.carstore.shared.dto.UserDto;

public class UserSessionDao extends BaseDao<UserSession> {
    private static final int TWO_WEEKS_AGO_IN_DAYS = -14;

    private final Logger logger;
    private final UserDao userDao;

    @Inject
    UserSessionDao(
            Logger logger,
            UserDao userDao) {
        super(UserSession.class);

        this.logger = logger;
        this.userDao = userDao;
    }

    public String createSessionCookie(UserDto userDto) {
        String cookie = UUID.randomUUID().toString();
        UserSession userSession = new UserSession(userDto.getId(), cookie);
        put(userSession);

        logger.info("UserSessionDao.createLoggedInCookie(user) user=" + userDto + " userSessionCookie="
                + userSession.getCookie());

        return userSession.getCookie();
    }

    public void removeLoggedInCookie(UserDto userDto) {
        UserSession userSession = findUserSession(userDto.getId());
        if (userSession != null) {
            delete(userSession);
        }

        logger.info("UserSessionDao.removeLoggedInCookie(user): Cookie is removed from database.");
    }

    public UserDto getUserFromCookie(String loggedInCookie) {
        Date twoWeeksAgo = getTwoWeeksAgo();

        UserSession userSession = ofy().load().type(UserSession.class)
                .filter("cookie", loggedInCookie)
                .filter("dateCreated > ", twoWeeksAgo)
                .first().now();

        if (userSession == null) {
            return null;
        }

        Long userId = userSession.getUserId();

        UserDto userDto = null;
        if (userId != null) {
            userDto = User.createDto(userDao.get(userId));
        }

        return userDto;
    }

    private Date getTwoWeeksAgo() {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.DATE, TWO_WEEKS_AGO_IN_DAYS);

        return calendar.getTime();
    }

    private UserSession findUserSession(Long userId) {
        Key<UserSession> key = Key.create(UserSession.class, userId);
        return ofy().load().type(UserSession.class).filterKey(key).first().now();
    }
}