Java tutorial
/* * Copyright (c) 2010-2011 Lockheed Martin Corporation * * 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 org.eurekastreams.server.action.execution.notification; import java.io.Serializable; import java.util.Date; import java.util.GregorianCalendar; import java.util.List; import org.apache.commons.logging.Log; import org.eurekastreams.commons.actions.ExecutionStrategy; import org.eurekastreams.commons.actions.context.ActionContext; import org.eurekastreams.commons.logging.LogFactory; import org.eurekastreams.server.persistence.mappers.DomainMapper; import org.eurekastreams.server.persistence.mappers.db.DeleteApplicationAlertsByDate; import org.eurekastreams.server.persistence.mappers.db.GetUserIdsWithUnreadApplicationAlertsByDate; /** * Deletes application that are older (in days) than the configured ageInDays value. */ public class DeleteOldApplicationAlertsExecution implements ExecutionStrategy<ActionContext> { /** * Logger. */ private final Log log = LogFactory.make(); /** * Mapper to delete alerts. */ private final DeleteApplicationAlertsByDate deleteMapper; /** * Mapper to find user ids with old unread alerts. */ private final GetUserIdsWithUnreadApplicationAlertsByDate unreadMapper; /** * Mapper to sync database and cache unread alert count. */ private final DomainMapper<Long, Integer> syncMapper; /** * Age at which alerts can be deleted. */ private final int ageInDays; /** * Constructor. * * @param inDeleteMapper * The mapper that performs the application alert deletion from the database. * @param inUnreadMapper * The mapper that retrieves the ids of users that have old unread alerts. * @param inSyncMapper * The mapper that syncs the unread alert count from the database with the value in cache. * @param inAgeInDays * The age in days when an alert is considered "old". */ public DeleteOldApplicationAlertsExecution(final DeleteApplicationAlertsByDate inDeleteMapper, final GetUserIdsWithUnreadApplicationAlertsByDate inUnreadMapper, final DomainMapper<Long, Integer> inSyncMapper, final int inAgeInDays) { deleteMapper = inDeleteMapper; ageInDays = inAgeInDays; unreadMapper = inUnreadMapper; syncMapper = inSyncMapper; } /** * {@inheritDoc} This method calls the database mapper to delete application alerts that are older than ageInDays. * Before the delete, a mapper call is made to find which users had old unread alerts then after the actual * deletion, the cached count of unread alerts for these users is synced with the database. */ @Override public Serializable execute(final ActionContext inActionContext) { if (log.isInfoEnabled()) { log.info("Deleting application alerts older than " + ageInDays + " days"); } GregorianCalendar calendar = new GregorianCalendar(); calendar.add(GregorianCalendar.DATE, ageInDays * -1); Date oldDate = calendar.getTime(); List<Long> userIdsToSync = unreadMapper.execute(oldDate); deleteMapper.execute(oldDate); for (long userId : userIdsToSync) { syncMapper.execute(userId); } return true; } }