How to check if a Localdate is a weekend?

Question

I have the following date of type LocalDate

2017-12-21

How to check if it’s a weekend?

I tried to use the Calendar, but it seems to only work with Date.

Answer 1

Just use the method getDayOfWeek(). This returns an element of enum DayOfWeek:

public static boolean fimDeSemana(LocalDate ld) {
    DayOfWeek d = ld.getDayOfWeek();
    return d == DayOfWeek.SATURDAY || d == DayOfWeek.SUNDAY;
}

Here’s a full test of it:

import java.time.DayOfWeek;
import java.time.LocalDate;

class Teste {

    public static boolean fimDeSemana(LocalDate ld) {
        DayOfWeek d = ld.getDayOfWeek();
        return d == DayOfWeek.SATURDAY || d == DayOfWeek.SUNDAY;
    }

    public static void main(String[] args) {
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 19))); // false, terça-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 20))); // false, quarta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 21))); // false, quinta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 22))); // false, sexta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 23))); // true, sábado
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 24))); // true, domingo
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 25))); // false, segunda-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 26))); // false, terça-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 27))); // false, quarta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 28))); // false, quinta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 29))); // false, sexta-feira
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 30))); // true, sábado
        System.out.println(fimDeSemana(LocalDate.of(2017, 12, 31))); // true, domingo
        System.out.println(fimDeSemana(LocalDate.of(2018,  1,  1))); // false, segunda-feira
    }
}

See here working on ideone.

Answer 2

To victor’s response is correct, just wanted to add another alternative.

Instead of a static method, you can also create a java.time.temporal.TemporalQuery:

// TemporalQuery que verifica se é fim de semana
TemporalQuery<Boolean> fds = t -> {
    DayOfWeek dow = DayOfWeek.from(t);
    return dow == DayOfWeek.SATURDAY || dow == DayOfWeek.SUNDAY;
};

To use it, just use the method query:

LocalDate dt = LocalDate.of(2017, 12, 21);
boolean fimDeSemana = dt.query(fds); // false

The great advantage is that a TemporalQuery can be used with any type that implements java.time.temporal.TemporalAccessor, as an example LocalDateTime, OffsetDateTime and ZonedDateTime (and any other class that implements TemporalAccessor and have a day of the week):

boolean fimDeSemana = ZonedDateTime.now().query(fds);

You can also use it directly with a java.time.format.DateTimeFormatter, for example, if your input is a String:

DateTimeFormatter fmt = DateTimeFormatter.ofPattern("dd/MM/uuuu");
boolean fimDeSemana = fmt.parse("21/12/2017", fds);

Although the static method works perfectly, I think using a TemporalQuery is more flexible, for the reasons above. But of course it all depends on your use cases.

---

Of course, if the class in question has no day of the week, an Exception will be launched:

// lança exception porque LocalTime não tem dia da semana
LocalTime.now().query(fds);

Answer 3

public class Horadiasdatalocalservice {

public static LocalTime horaLocal() {

    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("kk:mm:ss");
    CharSequence localTime = LocalTime.now().toString();


    return LocalTime.parse(localTime, dateTimeFormatter);

}

public static LocalDate dataLocal() {

        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");
        CharSequence localDate = LocalDate.now().toString();


        return LocalDate.parse(localDate, dateTimeFormatter);

    }

// MAXIMUM 3 BUSINESS DAYS BOOKING BOOK.............

public static LocalDate dataReservaLimite() {

    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");

    LocalDate localDatePlus3 = LocalDate.now().plusDays(3); 

    LocalDate localDateAnalyzed = verificarFinalDeSemana(localDatePlus3);


    return LocalDate.parse(localDateAnalyzed.toString(), dateTimeFormatter);

}

// MAXIMUM 10 WORKING DAYS TO RENT THE BOOK.............

public static LocalDate dataEmprestimoDevolucao() {

    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");

    LocalDate localDatePlus10 = LocalDate.now().plusDays(10);   

    LocalDate localDateAnalyzed = verificarFinalDeSemana(localDatePlus10);


    return LocalDate.parse(localDateAnalyzed.toString(), dateTimeFormatter);


}



public static LocalDate dataRenovacaoEmprestimo(Long idEmprestimo) {


    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy/MM/dd");

    LocalDate localDatePlus10 = LocalDate.now().plusDays(10);   

    LocalDate localDateAnalyzed = verificarFinalDeSemana(localDatePlus10);


    return LocalDate.parse(localDateAnalyzed.toString(), dateTimeFormatter);


}


//"PROXIMO DIA UTIL"
private static LocalDate verificarFinalDeSemana(LocalDate dataAgendada) {

    LocalDate dataAnalyzed = dataAgendada;

    if (dataAgendada.getDayOfWeek() == DayOfWeek.SATURDAY){

        dataAnalyzed = dataAgendada.plusDays(2);

    } else if(dataAgendada.getDayOfWeek() == DayOfWeek.SUNDAY) {

        dataAnalyzed = dataAgendada.plusDays(1);

    } 
    return dataAnalyzed;


}

Answer 4

I got it this way...

    import java.util.*;
    public class Data{
         public static void main(String[] args) {

         //Instanciando a classe Calendar juntamente com a classe GregorianCalendar
         Calendar data = new GregorianCalendar();

         //Condicação do que diz qual o dia da semana apartir da data do sistema
         switch(data.get(Calendar.DAY_OF_WEEK)){
            case 1:
                System.out.println("Domingo");
                break;
            case 2:
                System.out.println("Segunda-feira");
                break;
            case 3:
                System.out.println("Terça-feira");
                break;
            case 4:
                System.out.println("Quarta-feira");
                break;
            case 5:
                System.out.println("Quinta-feira");
                break;
            case 6:
                System.out.println("Sexta-feira");
                break;
            case 7:
                System.out.println("Sabado");
                break;
        }

        //COMPLETANDO... CASO SEJA FIM DE SEMANA OU MEIO DE SEMANA...
        if ((data.get(Calendar.DAY_OF_WEEK) == 7) || (data.get(Calendar.DAY_OF_WEEK) == 1){
            System.out.println("Fim de Semana");
        } else {
            System.out.println("Dias úteis");
        }
        System.out.println("\n\nFIM DO PROGRAMA!!!");
    } 
}

NOTE: I activate the Calendar class, so I didn’t really answer the question asked, but I did this other algorithm and it seems that it worked tmb...

import java.time.*;
public class Data{
public static void main(String[] args) {

    LocalDate data = LocalDate.now();
    DayOfWeek sabado = DayOfWeek.of(6);
    DayOfWeek domingo = DayOfWeek.of(7);

    if (data.getDayOfWeek().equals(sabado)){
        System.out.println("Fim de Semana!");
    } else if(data.getDayOfWeek().equals(domingo)) {
        System.out.println("Fim de Semana!");
    } else{
        System.out.println("Qualquer dia comum da semana!");
    }

    System.out.println("\n\nFIM DO PROGRAMA!!!");
}

}