Java tutorial
/* * Licensed to Metamarkets Group Inc. (Metamarkets) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. Metamarkets licenses this file * to you 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 io.druid.java.util.common; import com.google.common.base.Predicate; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import com.google.common.collect.Sets; import io.druid.java.util.common.guava.Comparators; import org.joda.time.DateTime; import org.joda.time.Interval; import java.util.ArrayList; import java.util.Iterator; import java.util.TreeSet; /** */ public class JodaUtils { public static ArrayList<Interval> condenseIntervals(Iterable<Interval> intervals) { ArrayList<Interval> retVal = Lists.newArrayList(); TreeSet<Interval> sortedIntervals = Sets.newTreeSet(Comparators.intervalsByStartThenEnd()); for (Interval interval : intervals) { sortedIntervals.add(interval); } if (sortedIntervals.isEmpty()) { return Lists.newArrayList(); } Iterator<Interval> intervalsIter = sortedIntervals.iterator(); Interval currInterval = intervalsIter.next(); while (intervalsIter.hasNext()) { Interval next = intervalsIter.next(); if (currInterval.overlaps(next) || currInterval.abuts(next)) { currInterval = new Interval(currInterval.getStart(), next.getEnd()); } else { retVal.add(currInterval); currInterval = next; } } retVal.add(currInterval); return retVal; } public static Interval umbrellaInterval(Iterable<Interval> intervals) { ArrayList<DateTime> startDates = Lists.newArrayList(); ArrayList<DateTime> endDates = Lists.newArrayList(); for (Interval interval : intervals) { startDates.add(interval.getStart()); endDates.add(interval.getEnd()); } DateTime minStart = minDateTime(startDates.toArray(new DateTime[] {})); DateTime maxEnd = maxDateTime(endDates.toArray(new DateTime[] {})); if (minStart == null || maxEnd == null) { throw new IllegalArgumentException("Empty list of intervals"); } return new Interval(minStart, maxEnd); } public static boolean overlaps(final Interval i, Iterable<Interval> intervals) { return Iterables.any(intervals, new Predicate<Interval>() { @Override public boolean apply(Interval input) { return input.overlaps(i); } }); } public static DateTime minDateTime(DateTime... times) { if (times == null) { return null; } switch (times.length) { case 0: return null; case 1: return times[0]; default: DateTime min = times[0]; for (int i = 1; i < times.length; ++i) { min = min.isBefore(times[i]) ? min : times[i]; } return min; } } public static DateTime maxDateTime(DateTime... times) { if (times == null) { return null; } switch (times.length) { case 0: return null; case 1: return times[0]; default: DateTime max = times[0]; for (int i = 1; i < times.length; ++i) { max = max.isAfter(times[i]) ? max : times[i]; } return max; } } }