Java tutorial
/* * The MIT License (MIT) * * Copyright (c) 2013 Anders Wisch * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package cron; import java.time.DayOfWeek; import java.time.Month; import java.time.ZonedDateTime; import java.time.temporal.ChronoUnit; import java.time.temporal.TemporalAdjusters; import java.util.Date; import com.google.common.base.Function; import com.google.common.collect.Iterables; public class DateTimes { public static Iterable<Date> toDates(Iterable<ZonedDateTime> times) { return Iterables.transform(times, new Function<ZonedDateTime, Date>() { @Override public Date apply(ZonedDateTime input) { return Date.from(input.toInstant()); } }); } public static ZonedDateTime midnight() { return now().truncatedTo(ChronoUnit.DAYS); } public static ZonedDateTime startOfHour() { return now().truncatedTo(ChronoUnit.HOURS); } public static ZonedDateTime now() { return ZonedDateTime.now(); } public static ZonedDateTime lastOfMonth(ZonedDateTime t, DayOfWeek dayOfWeek) { ZonedDateTime day = t.with(TemporalAdjusters.lastDayOfMonth()).with(dayOfWeek); if (day.getMonth() != t.getMonth()) day = day.minusWeeks(1); return day; } public static ZonedDateTime nthOfMonth(ZonedDateTime t, DayOfWeek dayOfWeek, int desiredNumber) { Month month = t.getMonth(); t = t.withDayOfMonth(1).with(dayOfWeek); if (t.getMonth() != month) t = t.plusWeeks(1); int number = 1; while (number < desiredNumber && t.getMonth() == month) { number++; t = t.plusWeeks(1); } return t; } public static ZonedDateTime nearestWeekday(ZonedDateTime t) { if (t.getDayOfWeek() == DayOfWeek.SATURDAY) return t.minusDays(1); else if (t.getDayOfWeek() == DayOfWeek.SUNDAY) return t.plusDays(1); return t; } public static ZonedDateTime startOfYear() { return midnight().withDayOfYear(1); } }