爪哇找到下一个发薪日

import java.time.Month;

import java.time.Year;

import java.time.LocalDate;

import java.time.DateTimeException;
/*
时 代 J a v a 公 众 号 提供
*/

import java.time.format.DateTimeFormatter;


import java.io.PrintStream;

import java.time.LocalDate;

import java.time.DayOfWeek;

import java.time.DateTimeException;


import java.time.temporal.Temporal;

import java.time.temporal.TemporalAdjuster;

import java.time.temporal.TemporalAdjusters;
//来自 时代Java

import java.io.PrintStream;


/**

 * 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);

    }

}

/**

 * This example takes a month and day from the command line and,

 * assuming the current year, prints the next payday.

 * This example uses the PaydayAdjuster class.

 */

public class NextPayday {


    public static void main(String[] args) {

        Month month = null;

        LocalDate date = null;

        DateTimeFormatter format;

        String out = null;


        if (args.length < 2) {

            System.out.printf("Usage: NextPayday <month> <day>%n");

            throw new IllegalArgumentException();

        }


        try {

            month = Month.valueOf(args[0].toUpperCase());

        } catch (IllegalArgumentException exc) {

            System.out.printf("%s is not a valid month.%n", args[0]);

            throw exc; // Rethrow the exception.

        }


        int day = Integer.parseInt(args[1]);


        try {

            date = Year.now().atMonth(month).atDay(day);

        } catch (DateTimeException exc) {

            System.out.printf("%s %s is not a valid date.%n", month, day);

            throw exc; // Rethrow the exception.

        }


        LocalDate nextPayday = date.with(new PaydayAdjuster());


        try {

            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);

        } catch (DateTimeException exc) {

            System.out.printf("%s can't be formatted!%n", out);

            throw exc;

        }


    }

}