Java tutorial
/* * SonarQube * Copyright (C) 2009-2017 SonarSource SA * mailto:info AT sonarsource DOT com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ package org.sonar.db.purge.period; import com.google.common.collect.Lists; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.List; import org.apache.commons.lang.time.DateUtils; import org.sonar.db.purge.PurgeableAnalysisDto; final class Interval { List<PurgeableAnalysisDto> snapshots = Lists.newArrayList(); void add(PurgeableAnalysisDto snapshot) { snapshots.add(snapshot); } List<PurgeableAnalysisDto> get() { return snapshots; } int count() { return snapshots.size(); } static List<Interval> group(List<PurgeableAnalysisDto> snapshots, Date start, Date end, int calendarField) { List<Interval> intervals = Lists.newArrayList(); GregorianCalendar calendar = new GregorianCalendar(); int lastYear = -1; int lastFieldValue = -1; Interval currentInterval = null; for (PurgeableAnalysisDto snapshot : snapshots) { if (!DateUtils.isSameDay(start, snapshot.getDate()) && snapshot.getDate().after(start) && (snapshot.getDate().before(end) || DateUtils.isSameDay(end, snapshot.getDate()))) { calendar.setTime(snapshot.getDate()); int currentFieldValue = calendar.get(calendarField); int currentYear = calendar.get(Calendar.YEAR); if (lastYear != currentYear || lastFieldValue != currentFieldValue) { currentInterval = new Interval(); intervals.add(currentInterval); } lastFieldValue = currentFieldValue; lastYear = currentYear; if (currentInterval != null) { currentInterval.add(snapshot); } } } return intervals; } }