public enum DayOfWeek extends Enum<DayOfWeek> implements TemporalAccessor, TemporalAdjuster
A day-of-week, such as 'Tuesday'.
DayOfWeek
is an enum representing the 7 days of the week - Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.
In addition to the textual enum name, each day-of-week has an int
value. The int
value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday). It is recommended that applications use the enum rather than the int
value to ensure code clarity.
This enum provides access to the localized textual form of the day-of-week. Some locales also assign different numeric values to the days, declaring Sunday to have the value 1, however this class provides no support for this. See WeekFields
for localized week-numbering.
Do not use ordinal()
to obtain the numeric representation of DayOfWeek
. Use getValue()
instead.
This enum represents a common concept that is found in many calendar systems. As such, this enum may be used by any calendar system that has the day-of-week concept defined exactly equivalent to the ISO calendar system.
public static final DayOfWeek MONDAY
The singleton instance for the day-of-week of Monday. This has the numeric value of 1
.
public static final DayOfWeek TUESDAY
The singleton instance for the day-of-week of Tuesday. This has the numeric value of 2
.
public static final DayOfWeek WEDNESDAY
The singleton instance for the day-of-week of Wednesday. This has the numeric value of 3
.
public static final DayOfWeek THURSDAY
The singleton instance for the day-of-week of Thursday. This has the numeric value of 4
.
public static final DayOfWeek FRIDAY
The singleton instance for the day-of-week of Friday. This has the numeric value of 5
.
public static final DayOfWeek SATURDAY
The singleton instance for the day-of-week of Saturday. This has the numeric value of 6
.
public static final DayOfWeek SUNDAY
The singleton instance for the day-of-week of Sunday. This has the numeric value of 7
.
public static DayOfWeek[] values()
Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
for (DayOfWeek c : DayOfWeek.values()) System.out.println(c);
public static DayOfWeek valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
name
- the name of the enum constant to be returned.IllegalArgumentException
- if this enum type has no constant with the specified nameNullPointerException
- if the argument is nullpublic static DayOfWeek of(int dayOfWeek)
Obtains an instance of DayOfWeek
from an int
value.
DayOfWeek
is an enum representing the 7 days of the week. This factory allows the enum to be obtained from the int
value. The int
value follows the ISO-8601 standard, from 1 (Monday) to 7 (Sunday).
dayOfWeek
- the day-of-week to represent, from 1 (Monday) to 7 (Sunday)DateTimeException
- if the day-of-week is invalidpublic static DayOfWeek from(TemporalAccessor temporal)
Obtains an instance of DayOfWeek
from a temporal object.
This obtains a day-of-week based on the specified temporal. A TemporalAccessor
represents an arbitrary set of date and time information, which this factory converts to an instance of DayOfWeek
.
The conversion extracts the DAY_OF_WEEK
field.
This method matches the signature of the functional interface TemporalQuery
allowing it to be used as a query via method reference, DayOfWeek::from
.
temporal
- the temporal object to convert, not nullDateTimeException
- if unable to convert to a DayOfWeek
public int getValue()
Gets the day-of-week int
value.
The values are numbered following the ISO-8601 standard, from 1 (Monday) to 7 (Sunday). See WeekFields.dayOfWeek()
for localized week-numbering.
public String getDisplayName(TextStyle style, Locale locale)
Gets the textual representation, such as 'Mon' or 'Friday'.
This returns the textual name used to identify the day-of-week, suitable for presentation to the user. The parameters control the style of the returned text and the locale.
If no textual mapping is found then the numeric value
is returned.
style
- the length of the text required, not nulllocale
- the locale to use, not nullpublic boolean isSupported(TemporalField field)
Checks if the specified field is supported.
This checks if this day-of-week can be queried for the specified field. If false, then calling the range
and get
methods will throw an exception.
If the field is DAY_OF_WEEK
then this method returns true. All other ChronoField
instances will return false.
If the field is not a ChronoField
, then the result of this method is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor)
passing this
as the argument. Whether the field is supported is determined by the field.
isSupported
in interface TemporalAccessor
field
- the field to check, null returns falsepublic ValueRange range(TemporalField field)
Gets the range of valid values for the specified field.
The range object expresses the minimum and maximum valid values for a field. This day-of-week is used to enhance the accuracy of the returned range. If it is not possible to return the range, because the field is not supported or for some other reason, an exception is thrown.
If the field is DAY_OF_WEEK
then the range of the day-of-week, from 1 to 7, will be returned. All other ChronoField
instances will throw an UnsupportedTemporalTypeException
.
If the field is not a ChronoField
, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessor)
passing this
as the argument. Whether the range can be obtained is determined by the field.
range
in interface TemporalAccessor
field
- the field to query the range for, not nullDateTimeException
- if the range for the field cannot be obtainedUnsupportedTemporalTypeException
- if the field is not supportedpublic int get(TemporalField field)
Gets the value of the specified field from this day-of-week as an int
.
This queries this day-of-week for the value of the specified field. The returned value will always be within the valid range of values for the field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.
If the field is DAY_OF_WEEK
then the value of the day-of-week, from 1 to 7, will be returned. All other ChronoField
instances will throw an UnsupportedTemporalTypeException
.
If the field is not a ChronoField
, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor)
passing this
as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.
get
in interface TemporalAccessor
field
- the field to get, not nullDateTimeException
- if a value for the field cannot be obtained or the value is outside the range of valid values for the fieldUnsupportedTemporalTypeException
- if the field is not supported or the range of values exceeds an int
ArithmeticException
- if numeric overflow occurspublic long getLong(TemporalField field)
Gets the value of the specified field from this day-of-week as a long
.
This queries this day-of-week for the value of the specified field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.
If the field is DAY_OF_WEEK
then the value of the day-of-week, from 1 to 7, will be returned. All other ChronoField
instances will throw an UnsupportedTemporalTypeException
.
If the field is not a ChronoField
, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor)
passing this
as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.
getLong
in interface TemporalAccessor
field
- the field to get, not nullDateTimeException
- if a value for the field cannot be obtainedUnsupportedTemporalTypeException
- if the field is not supportedArithmeticException
- if numeric overflow occurspublic DayOfWeek plus(long days)
Returns the day-of-week that is the specified number of days after this one.
The calculation rolls around the end of the week from Sunday to Monday. The specified period may be negative.
This instance is immutable and unaffected by this method call.
days
- the days to add, positive or negativepublic DayOfWeek minus(long days)
Returns the day-of-week that is the specified number of days before this one.
The calculation rolls around the start of the year from Monday to Sunday. The specified period may be negative.
This instance is immutable and unaffected by this method call.
days
- the days to subtract, positive or negativepublic <R> R query(TemporalQuery<R> query)
Queries this day-of-week using the specified query.
This queries this day-of-week using the specified query strategy object. The TemporalQuery
object defines the logic to be used to obtain the result. Read the documentation of the query to understand what the result of this method will be.
The result of this method is obtained by invoking the TemporalQuery.queryFrom(TemporalAccessor)
method on the specified query passing this
as the argument.
query
in interface TemporalAccessor
R
- the type of the resultquery
- the query to invoke, not nullDateTimeException
- if unable to query (defined by the query)ArithmeticException
- if numeric overflow occurs (defined by the query)public Temporal adjustInto(Temporal temporal)
Adjusts the specified temporal object to have this day-of-week.
This returns a temporal object of the same observable type as the input with the day-of-week changed to be the same as this.
The adjustment is equivalent to using Temporal.with(TemporalField, long)
passing ChronoField.DAY_OF_WEEK
as the field. Note that this adjusts forwards or backwards within a Monday to Sunday week. See WeekFields.dayOfWeek()
for localized week start days. See TemporalAdjuster
for other adjusters with more control, such as next(MONDAY)
.
In most cases, it is clearer to reverse the calling pattern by using Temporal.with(TemporalAdjuster)
:
// these two lines are equivalent, but the second approach is recommended temporal = thisDayOfWeek.adjustInto(temporal); temporal = temporal.with(thisDayOfWeek);
For example, given a date that is a Wednesday, the following are output:
dateOnWed.with(MONDAY); // two days earlier dateOnWed.with(TUESDAY); // one day earlier dateOnWed.with(WEDNESDAY); // same date dateOnWed.with(THURSDAY); // one day later dateOnWed.with(FRIDAY); // two days later dateOnWed.with(SATURDAY); // three days later dateOnWed.with(SUNDAY); // four days later
This instance is immutable and unaffected by this method call.
adjustInto
in interface TemporalAdjuster
temporal
- the target object to be adjusted, not nullDateTimeException
- if unable to make the adjustmentArithmeticException
- if numeric overflow occurs
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