Hướng dẫn và ví dụ Java TemporalAdjusters

public static TemporalAdjuster ofDateAdjuster(UnaryOperator<LocalDate> dateBasedAdjuster)

public static TemporalAdjuster firstDayOfMonth()  
public static TemporalAdjuster lastDayOfMonth()  

public static TemporalAdjuster firstDayOfNextMonth()  

public static TemporalAdjuster firstDayOfYear()  
public static TemporalAdjuster lastDayOfYear()  

public static TemporalAdjuster firstDayOfNextYear()

public static TemporalAdjuster firstInMonth(DayOfWeek dayOfWeek)  
public static TemporalAdjuster lastInMonth(DayOfWeek dayOfWeek)  

public static TemporalAdjuster dayOfWeekInMonth(int ordinal, DayOfWeek dayOfWeek)

public static TemporalAdjuster next(DayOfWeek dayOfWeek)   
public static TemporalAdjuster nextOrSame(DayOfWeek dayOfWeek)  

public static TemporalAdjuster previous(DayOfWeek dayOfWeek)   
public static TemporalAdjuster previousOrSame(DayOfWeek dayOfWeek)

public static TemporalAdjuster ofDateAdjuster(UnaryOperator<LocalDate> dateBasedAdjuster) {
    Objects.requireNonNull(dateBasedAdjuster, "dateBasedAdjuster");
    return (temporal) -> {
        LocalDate input = LocalDate.from(temporal);
        LocalDate output = dateBasedAdjuster.apply(input);
        return temporal.with(output);
    };
}

package org.o7planning.temporaladjusters.ex;

import java.time.ZonedDateTime;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAdjusters;

public class TemporalAdjusters_ofDateAdjuster_ex1 {
    public static void main(String[] args) {
        TemporalAdjuster add2DaysAdjuster = TemporalAdjusters.ofDateAdjuster(localDate -> localDate.plusDays(2));
        
        ZonedDateTime zonedDateTime = ZonedDateTime.now();
        ZonedDateTime after2Days = zonedDateTime.with(add2DaysAdjuster);
        
        System.out.println("zonedDateTime: " + zonedDateTime);
        System.out.println("after2Days: " + after2Days);
    }
}

public static TemporalAdjuster firstDayOfMonth()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate firstDayOfMonth = (LocalDate) TemporalAdjusters.firstDayOfMonth().adjustInto(localDate);
System.out.println("firstDayOfMonth: " + firstDayOfMonth);

DayOfWeek dayOfWeek = firstDayOfMonth.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

public static TemporalAdjuster lastDayOfMonth()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate lastDayOfMonth = (LocalDate) TemporalAdjusters.lastDayOfMonth().adjustInto(localDate);
System.out.println("lastDayOfMonth: " + lastDayOfMonth);

DayOfWeek dayOfWeek = lastDayOfMonth.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

public static TemporalAdjuster firstDayOfNextMonth()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate firstDayOfNextMonth = (LocalDate) localDate.with(TemporalAdjusters.firstDayOfNextMonth());
System.out.println("firstDayOfNextMonth: " + firstDayOfNextMonth);

DayOfWeek dayOfWeek = firstDayOfNextMonth.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

int dayOfMonth = firstDayOfNextMonth.getDayOfMonth();
System.out.println(" > day of month: " + dayOfMonth);

public static TemporalAdjuster firstDayOfYear()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate firstDayOfYear = (LocalDate) localDate.with(TemporalAdjusters.firstDayOfYear());
System.out.println("firstDayOfYear: " + firstDayOfYear);

DayOfWeek dayOfWeek = firstDayOfYear.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

public static TemporalAdjuster lastDayOfYear()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate lastDayOfYear = (LocalDate) localDate.with(TemporalAdjusters.lastDayOfYear());
System.out.println("lastDayOfYear: " + lastDayOfYear);

DayOfWeek dayOfWeek = lastDayOfYear.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

public static TemporalAdjuster firstDayOfNextYear()

LocalDate localDate = LocalDate.now();
System.out.println("today is: " + localDate);

LocalDate firstDayOfNextYear = (LocalDate) localDate.with(TemporalAdjusters.firstDayOfNextYear());
System.out.println("firstDayOfNextYear: " + firstDayOfNextYear);

DayOfWeek dayOfWeek = firstDayOfNextYear.getDayOfWeek();
System.out.println(" > day of week: " + dayOfWeek);

int dayOfYear = firstDayOfNextYear.getDayOfYear();
System.out.println(" > day of year: " + dayOfYear);

public static TemporalAdjuster firstInMonth(DayOfWeek dayOfWeek)

// Find the first SUNDAY in month.
TemporalAdjuster adjuster1 = TemporalAdjusters.firstInMonth(DayOfWeek.SUNDAY);
// Find the next SUNDAY
TemporalAdjuster adjuster2 = TemporalAdjusters.next(DayOfWeek.SUNDAY);

LocalDate localDate = LocalDate.of(2025, 3, 1); // 2025-03-01

LocalDate firstSundayInMonth = (LocalDate) localDate.with(adjuster1);
LocalDate secondSundayInMonth = (LocalDate) firstSundayInMonth.with(adjuster2);

System.out.println("firstSaturdayInMonth: " + firstSundayInMonth); // 2025-03-02
System.out.println("secondSundayInMonth: " + secondSundayInMonth);  // 2025-03-09

public static TemporalAdjuster lastInMonth(DayOfWeek dayOfWeek)

// Find the last SUNDAY in month.
TemporalAdjuster adjuster = TemporalAdjusters.lastInMonth(DayOfWeek.SUNDAY);  

LocalDate localDate = LocalDate.now();
System.out.println("Today is: " + localDate);

LocalDate lastSundayInMonth = (LocalDate) localDate.with(adjuster);  
System.out.println("lastSundayInMonth: " + lastSundayInMonth);

public static TemporalAdjuster dayOfWeekInMonth(int ordinal, DayOfWeek dayOfWeek)

// Find the second SUNDAY in month.
TemporalAdjuster adjuster = TemporalAdjusters.dayOfWeekInMonth(2, DayOfWeek.SUNDAY);  

LocalDate localDate = LocalDate.of(2025, 3, 1); // 2025-03-01
 
LocalDate secondSundayInMonth = (LocalDate) localDate.with(adjuster);   
System.out.println("secondSundayInMonth: " + secondSundayInMonth);  // 2025-03-09

public static TemporalAdjuster next(DayOfWeek dayOfWeek)

// Find the next MONDAY
TemporalAdjuster adjuster = TemporalAdjusters.next(DayOfWeek.MONDAY);  

LocalDate localDate = LocalDate.of(2021, 7, 5); // 2021-07-05
System.out.println("localDate: " + localDate);  // 2021-07-05
System.out.println("localDate.getDayOfWeek(): " + localDate.getDayOfWeek());  // MONDAY
 
// Next MONDAY.
LocalDate nextMonday = localDate.with(adjuster);
 
System.out.println("nextMonday: " + nextMonday);  // 2021-07-12
System.out.println("nextMonday.getDayOfWeek(): " + nextMonday.getDayOfWeek());  // MONDAY

public static TemporalAdjuster nextOrSame(DayOfWeek dayOfWeek)

// Find the next or same MONDAY
TemporalAdjuster adjuster = TemporalAdjusters.nextOrSame(DayOfWeek.MONDAY);  

LocalDate localDate = LocalDate.of(2021, 7, 5); // 2021-07-05
System.out.println("localDate: " + localDate);  // 2021-07-05
System.out.println("localDate.getDayOfWeek(): " + localDate.getDayOfWeek());  // MONDAY
 
// Next or same MONDAY.
LocalDate nextOrSameMonday = localDate.with(adjuster);
 
System.out.println("nextOrSameMonday: " + nextOrSameMonday);  // 2021-07-05
System.out.println("nextOrSameMonday.getDayOfWeek(): " + nextOrSameMonday.getDayOfWeek());  // MONDAY

public static TemporalAdjuster previous(DayOfWeek dayOfWeek)

// Find the previous MONDAY
TemporalAdjuster adjuster = TemporalAdjusters.previous(DayOfWeek.MONDAY);  

LocalDate localDate = LocalDate.of(2021, 7, 5); // 2021-07-05
System.out.println("localDate: " + localDate);  // 2021-07-05
System.out.println("localDate.getDayOfWeek(): " + localDate.getDayOfWeek());  // MONDAY
 
// Previous MONDAY.
LocalDate previousMonday = localDate.with(adjuster);
 
System.out.println("previousMonday: " + previousMonday);  // 2021-06-28
System.out.println("previousMonday.getDayOfWeek(): " + previousMonday.getDayOfWeek());  // MONDAY

public static TemporalAdjuster previousOrSame(DayOfWeek dayOfWeek)

// Find the previous or same MONDAY
TemporalAdjuster adjuster = TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY);  

LocalDate localDate = LocalDate.of(2021, 7, 5); // 2021-07-05
System.out.println("localDate: " + localDate);  // 2021-07-05
System.out.println("localDate.getDayOfWeek(): " + localDate.getDayOfWeek());  // MONDAY
 
// Previous or same MONDAY.
LocalDate previousOrSameMonday = localDate.with(adjuster);
 
System.out.println("previousOrSameMonday: " + previousOrSameMonday);  // 2021-07-05
System.out.println("previousOrSameMonday.getDayOfWeek(): " + previousOrSameMonday.getDayOfWeek());  // MONDAY