Android Calendar get current day of week as string [duplicate]

问题

This question already has an answer here:

Android: how to get the current day of the week (Monday, etc…) in the user's language? 10 answers

i tried to get a string with the name of the actual weekday this way:

            Calendar c = Calendar.getInstance();
            int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);

            if (c.get(Calendar.MONDAY) == dayOfWeek) weekDay = "monday";
            else if (c.get(Calendar.TUESDAY) == dayOfWeek) weekDay = "tuesday";
            else if (c.get(Calendar.WEDNESDAY) == dayOfWeek) weekDay = "wednesday";
            else if (c.get(Calendar.THURSDAY) == dayOfWeek) weekDay = "thursday";
            else if (c.get(Calendar.FRIDAY) == dayOfWeek) weekDay = "friday";
            else if (c.get(Calendar.SATURDAY) == dayOfWeek) weekDay = "saturday";
            else if (c.get(Calendar.SUNDAY) == dayOfWeek) weekDay = "sunday";

but weekDay stays always null and i actually have no idea why because the debugger says that dayOfWeek is 5 so i should be equal to c.get(Calendar.THURSDAY)

回答1:

As simple as this

sCalendar = Calendar.getInstance();
String dayLongName = sCalendar.getDisplayName(Calendar.DAY_OF_WEEK, Calendar.LONG, Locale.getDefault());

回答2:

I accomplished this by doing the following:

String weekDay;
SimpleDateFormat dayFormat = new SimpleDateFormat("EEEE", Locale.US);

Calendar calendar = Calendar.getInstance();
weekDay = dayFormat.format(calendar.getTime());

Use the day format for "EEEE" will return the full weekday name, i.e. Tuesday
Use the day format for "E" will return the the abbreviated name, i.e. Tue
Another benefit to returning this format in Android is that it will translate the weekday based on the locale.

You will want to review the SimpleDateFormat to learn more. I think this is the cleanest approach in that you do not need a switch or if statement if your only need is to get the string value.

回答3:

You are supposed to compare dayOfWeek directly with Calendar.MONDAY etc. See code below

Also, I have put brackets around if else. Do not rely on indentation for code flow, explicitly put brackets even if your if-else has only one statement.

    public static void main(String[] args) {

    String weekDay = "";

    Calendar c = Calendar.getInstance();
    int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);

    if (Calendar.MONDAY == dayOfWeek) {
        weekDay = "monday";
    } else if (Calendar.TUESDAY == dayOfWeek) {
        weekDay = "tuesday";
    } else if (Calendar.WEDNESDAY == dayOfWeek) {
        weekDay = "wednesday";
    } else if (Calendar.THURSDAY == dayOfWeek) {
        weekDay = "thursday";
    } else if (Calendar.FRIDAY == dayOfWeek) {
        weekDay = "friday";
    } else if (Calendar.SATURDAY == dayOfWeek) {
        weekDay = "saturday";
    } else if (Calendar.SUNDAY == dayOfWeek) {
        weekDay = "sunday";
    }

    System.out.println(weekDay);

}

回答4:

There was no need to use the c.get

    Calendar c = Calendar.getInstance();
    int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);                

    if (Calendar.MONDAY == dayOfWeek) weekDay = "monday";
    else if (Calendar.TUESDAY == dayOfWeek) weekDay = "tuesday";
    else if (Calendar.WEDNESDAY == dayOfWeek) weekDay = "wednesday";
    else if (Calendar.THURSDAY == dayOfWeek) weekDay = "thursday";
    else if (Calendar.FRIDAY == dayOfWeek) weekDay = "friday";
    else if (Calendar.SATURDAY == dayOfWeek) weekDay = "saturday";
    else if (Calendar.SUNDAY == dayOfWeek) weekDay = "sunday";

    System.out.println(weekDay);

and output:

thursday

You can see your error if you try to print the values with c.get with this code

    System.out.println(c.get(Calendar.MONDAY));
    System.out.println(c.get(Calendar.TUESDAY));
    System.out.println(c.get(Calendar.WEDNESDAY));
    System.out.println(c.get(Calendar.THURSDAY));
    System.out.println(c.get(Calendar.FRIDAY));
    System.out.println(c.get(Calendar.SATURDAY));
    System.out.println(c.get(Calendar.SUNDAY));

For example I get:

And the result will be incorrect, in my case I get Sunday as weekDay if I use your code.

回答5:

just do the following:

    Date date = new Date();
    CharSequence time = DateFormat.format("EEEE", date.getTime()); // gives like (Wednesday)

回答6:

try this

import java.text.DateFormatSymbols;
import java.util.Date;
...
String[] weekdays = new DateFormatSymbols().getWeekdays();
String[] month = new DateFormatSymbols().getMonths();
System.outprintln(weekdays[date.getDay()+1]+","+month[date.getMonth()]+" "+date.getDate());

来源：https://stackoverflow.com/questions/18256521/android-calendar-get-current-day-of-week-as-string

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dayofweek