public enum DayOfWeek extends Enum<DayOfWeek> implements TemporalAccessor, TemporalAdjuster
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.
This is an immutable and thread-safe enum.
Enum Constant and Description |
---|
FRIDAY
The singleton instance for the day-of-week of Friday.
|
MONDAY
The singleton instance for the day-of-week of Monday.
|
SATURDAY
The singleton instance for the day-of-week of Saturday.
|
SUNDAY
The singleton instance for the day-of-week of Sunday.
|
THURSDAY
The singleton instance for the day-of-week of Thursday.
|
TUESDAY
The singleton instance for the day-of-week of Tuesday.
|
WEDNESDAY
The singleton instance for the day-of-week of Wednesday.
|
Modifier and Type | Method and Description |
---|---|
Temporal |
adjustInto(Temporal temporal)
Adjusts the specified temporal object to have this day-of-week.
|
static DayOfWeek |
from(TemporalAccessor temporal)
Obtains an instance of
DayOfWeek from a temporal object. |
int |
get(TemporalField field)
Gets the value of the specified field from this day-of-week as an
int . |
long |
getLong(TemporalField field)
Gets the value of the specified field from this day-of-week as a
long . |
int |
getValue()
Gets the day-of-week
int value. |
boolean |
isSupported(TemporalField field)
Checks if the specified field is supported.
|
DayOfWeek |
minus(long days)
Returns the day-of-week that is the specified number of days before this one.
|
static DayOfWeek |
of(int dayOfWeek)
Obtains an instance of
DayOfWeek from an int value. |
DayOfWeek |
plus(long days)
Returns the day-of-week that is the specified number of days after this one.
|
<R> R |
query(TemporalQuery<R> query)
Queries this day-of-week using the specified query.
|
ValueRange |
range(TemporalField field)
Gets the range of valid values for the specified field.
|
static DayOfWeek |
valueOf(String name)
Returns the enum constant of this type with the specified name.
|
static DayOfWeek[] |
values()
Returns an array containing the constants of this enum type, in
the order they are declared.
|
public static final DayOfWeek FRIDAY
5
.public static final DayOfWeek MONDAY
1
.public static final DayOfWeek SATURDAY
6
.public static final DayOfWeek SUNDAY
7
.public static final DayOfWeek THURSDAY
4
.public static final DayOfWeek TUESDAY
2
.public static final DayOfWeek WEDNESDAY
3
.public Temporal adjustInto(Temporal temporal)
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 adjustmentpublic static DayOfWeek from(TemporalAccessor temporal)
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 get(TemporalField field)
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
public long getLong(TemporalField field)
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 supportedpublic int getValue()
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 boolean isSupported(@Nullable TemporalField field)
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 DayOfWeek minus(long days)
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 static DayOfWeek of(int dayOfWeek)
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 DayOfWeek plus(long days)
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 negative@Nullable public <R> R query(TemporalQuery<R> 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)public ValueRange range(TemporalField 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 static DayOfWeek valueOf(String name)
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[] values()
for (DayOfWeek c : DayOfWeek.values()) System.out.println(c);