Java tutorial
/** * Licensed to JumpMind Inc under one or more contributor * license agreements. See the NOTICE file distributed * with this work for additional information regarding * copyright ownership. JumpMind Inc licenses this file * to you under the GNU General Public License, version 3.0 (GPLv3) * (the "License"); you may not use this file except in compliance * with the License. * * You should have received a copy of the GNU General Public License, * version 3.0 (GPLv3) along with this library; if not, see * <http://www.gnu.org/licenses/>. * * 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.jumpmind.symmetric.statistic; import java.math.BigDecimal; import java.util.Calendar; import java.util.Date; import java.util.Iterator; import java.util.List; import java.util.TreeMap; import org.apache.commons.lang.time.DateUtils; abstract public class AbstractStatsByPeriodMap<T, M extends AbstractNodeHostStats> extends TreeMap<Date, T> { private static final long serialVersionUID = 1L; public AbstractStatsByPeriodMap(Date start, Date end, List<M> list, int periodSizeInMinutes) { Iterator<M> stats = list.iterator(); Calendar startCal = Calendar.getInstance(); startCal.setTime(start); startCal.set(Calendar.SECOND, 0); startCal.set(Calendar.MILLISECOND, 0); startCal.set(Calendar.MINUTE, round(startCal.get(Calendar.MINUTE))); Date periodStart = startCal.getTime(); Date periodEnd = DateUtils.addMinutes(periodStart, periodSizeInMinutes); M stat = null; while (periodStart.before(end)) { if (stat == null && stats.hasNext()) { stat = stats.next(); } if (stat != null && (periodStart.equals(stat.getStartTime()) || periodStart.before(stat.getStartTime())) && periodEnd.after(stat.getStartTime())) { add(periodStart, stat); stat = null; } else { if (stat != null && stat.getStartTime().before(periodStart)) { stat = null; } if (!containsKey(periodStart)) { addBlank(periodStart); } periodStart = periodEnd; periodEnd = DateUtils.addMinutes(periodStart, periodSizeInMinutes); } } } abstract protected void addBlank(Date periodStart); abstract protected void add(Date periodStart, M stat); protected int round(int value) { return 5 * new BigDecimal((double) value / 5d).setScale(2, BigDecimal.ROUND_HALF_DOWN).intValue(); } }