2. import java.time.Month;
    3. import java.time.Year;
    4. import java.time.LocalDate;
    5. import java.time.DateTimeException;
    6. import java.time.format.DateTimeFormatter;
    8. import java.io.PrintStream;
    10. /**
    11.  * This example takes a month and day from the command line and,
    12.  * assuming the current year, prints the next payday.
    13.  * This example uses the PaydayAdjuster class.
    14.  */
    15. public class NextPayday {
    17.     public static void main(String[] args) {
    18.         Month month = null;
    19.         LocalDate date = null;
    20.         DateTimeFormatter format;
    21.         String out = null;
    23.         if (args.length < 2)
    24.         {
    25.             System.out.printf("Usage: NextPayday <month> <day>%n");
    26.             throw new IllegalArgumentException();
    27.         }
    29.         try {
    30.             month = Month.valueOf(args[0].toUpperCase());
    31.         } catch (IllegalArgumentException exc) {
    32.             System.out.printf("%s is not a valid month.%n", args[0]);
    33.             throw exc;   // Rethrow the exception.
    34.         }
    36.         int day = Integer.parseInt(args[1]);
    38.         try {
    39.             date = Year.now().atMonth(month).atDay(day);
    40.         } catch (DateTimeException exc) {
    41.             System.out.printf("%s %s is not a valid date.%n", month, day);
    42.             throw exc;   // Rethrow the exception.
    43.         }
    45.         LocalDate nextPayday = date.with(new PaydayAdjuster());
    47.         try {
    48.             format = DateTimeFormatter.ofPattern("yyyy MMM d");
    49.             out = date.format(format);
    50.             System.out.printf("Given the date:  %s%n", out);
    51.             out = nextPayday.format(format);
    52.             System.out.printf("the next payday: %s%n", out);
    53.         } catch (DateTimeException exc) {
    54.             System.out.printf("%s can't be formatted!%n", out);
    55.             throw exc;
    56.         }
    58.     }
    59. }
    2. import java.time.LocalDate;
    3. import java.time.DayOfWeek;
    4. import java.time.DateTimeException;
    6. import java.time.temporal.Temporal;
    7. import java.time.temporal.TemporalAdjuster;
    8. import java.time.temporal.TemporalAdjusters;
    10. import java.io.PrintStream;
    12. /**
    13.  * This temporal adjuster assumes that payday occurs on the 15th
    14.  * and the last day of each month. However, if either of those
    15.  * days lands on a weekend, then the previous Friday is used.
    16.  */
    17. public class PaydayAdjuster implements TemporalAdjuster {
    19.     /**
    20.      * The adjustInto method accepts a Temporal instance
    21.      * and returns an adjusted LocalDate. If the passed in
    22.      * parameter is not a LocalDate, then a DateTimeException is thrown.
    23.      */
    24.     public Temporal adjustInto(Temporal input) {
    25.         LocalDate date = LocalDate.from(input);
    26.         int day;
    27.         if (date.getDayOfMonth() < 15) {
    28.             day = 15;
    29.         } else {
    30.             day = date.with(TemporalAdjusters.lastDayOfMonth()).getDayOfMonth();
    31.         }
    32.         date = date.withDayOfMonth(day);
    33.         if (date.getDayOfWeek() == DayOfWeek.SATURDAY ||
    34.             date.getDayOfWeek() == DayOfWeek.SUNDAY) {
    35.             date = date.with(TemporalAdjusters.previous(DayOfWeek.FRIDAY));
    36.         }
    38.         return input.with(date);
    39.     }
    40. }