Java tutorial
import java.time.DayOfWeek; import java.time.LocalDate; import java.time.Month; import java.time.Year; import java.time.format.DateTimeFormatter; import java.time.temporal.Temporal; import java.time.temporal.TemporalAdjuster; import java.time.temporal.TemporalAdjusters; public class Main { public static void main(String[] args) { Month month = null; LocalDate date = null; DateTimeFormatter format; String out = null; month = Month.valueOf("May".toUpperCase()); date = Year.now().atMonth(month).atDay(12); LocalDate nextPayday = date.with(new PaydayAdjuster()); format = DateTimeFormatter.ofPattern("yyyy MMM d"); out = date.format(format); System.out.printf("Given the date: %s%n", out); out = nextPayday.format(format); System.out.printf("the next payday: %s%n", out); } } /** * This temporal adjuster assumes that payday occurs on the 15th * and the last day of each month. However, if either of those * days lands on a weekend, then the previous Friday is used. */ class PaydayAdjuster implements TemporalAdjuster { /** * The adjustInto method accepts a Temporal instance * and returns an adjusted LocalDate. If the passed in * parameter is not a LocalDate, then a DateTimeException is thrown. */ public Temporal adjustInto(Temporal input) { LocalDate date = LocalDate.from(input); int day; if (date.getDayOfMonth() < 15) { day = 15; } else { day = date.with(TemporalAdjusters.lastDayOfMonth()).getDayOfMonth(); } date = date.withDayOfMonth(day); if (date.getDayOfWeek() == DayOfWeek.SATURDAY || date.getDayOfWeek() == DayOfWeek.SUNDAY) { date = date.with(TemporalAdjusters.previous(DayOfWeek.FRIDAY)); } return input.with(date); } } /* * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */