TemporalAccessor

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public interface TemporalAccessor
Known Indirect Subclasses

Framework-level interface defining read-only access to a temporal object, such as a date, time, offset or some combination of these.

This is the base interface type for date, time and offset objects. It is implemented by those classes that can provide information as {@linkplain TemporalField fields} or {@linkplain TemporalQuery queries}.

Most date and time information can be represented as a number. These are modeled using TemporalField with the number held using a long to handle large values. Year, month and day-of-month are simple examples of fields, but they also include instant and offsets. See ChronoField for the standard set of fields.

Two pieces of date/time information cannot be represented by numbers, the {@linkplain java.time.chrono.Chronology chronology} and the {@linkplain java.time.ZoneId time-zone}. These can be accessed via {@linkplain #query(TemporalQuery) queries} using the static methods defined on TemporalQuery.

A sub-interface, Temporal, extends this definition to one that also supports adjustment and manipulation on more complete temporal objects.

This interface is a framework-level interface that should not be widely used in application code. Instead, applications should create and pass around instances of concrete types, such as LocalDate. There are many reasons for this, part of which is that implementations of this interface may be in calendar systems other than ISO. See ChronoLocalDate for a fuller discussion of the issues.

Public Method Summary

int
get(TemporalField field)
Gets the value of the specified field as an int.
abstract long
getLong(TemporalField field)
Gets the value of the specified field as a long.
abstract boolean
isSupported(TemporalField field)
Checks if the specified field is supported.
<R> R
query(TemporalQuery<R> query)
Queries this date-time.
ValueRange
range(TemporalField field)
Gets the range of valid values for the specified field.

Public Methods

public int get (TemporalField field)

Gets the value of the specified field as an int.

This queries the date-time for the value of the specified field. The returned value will always be within the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.

Parameters
field the field to get, not null
Returns
  • the value for the field, within the valid range of values
Throws
DateTimeException if a value for the field cannot be obtained or the value is outside the range of valid values for the field
UnsupportedTemporalTypeException if the field is not supported or the range of values exceeds an int
ArithmeticException if numeric overflow occurs

public abstract long getLong (TemporalField field)

Gets the value of the specified field as a long.

This queries the date-time for the value of the specified field. The returned value may be outside the valid range of values for the field. If the date-time cannot return the value, because the field is unsupported or for some other reason, an exception will be thrown.

Parameters
field the field to get, not null
Returns
  • the value for the field
Throws
DateTimeException if a value for the field cannot be obtained
UnsupportedTemporalTypeException if the field is not supported
ArithmeticException if numeric overflow occurs

public abstract boolean isSupported (TemporalField field)

Checks if the specified field is supported.

This checks if the date-time can be queried for the specified field. If false, then calling the range and get methods will throw an exception.

Parameters
field the field to check, null returns false
Returns
  • true if this date-time can be queried for the field, false if not

public R query (TemporalQuery<R> query)

Queries this date-time.

This queries this date-time using the specified query strategy object.

Queries are a key tool for extracting information from date-times. They exists to externalize the process of querying, permitting different approaches, as per the strategy design pattern. Examples might be a query that checks if the date is the day before February 29th in a leap year, or calculates the number of days to your next birthday.

The most common query implementations are method references, such as LocalDate::from and ZoneId::from. Additional implementations are provided as static methods on TemporalQuery.

Parameters
query the query to invoke, not null
Returns
  • the query result, null may be returned (defined by the query)
Throws
DateTimeException if unable to query
ArithmeticException if numeric overflow occurs

public ValueRange range (TemporalField field)

Gets the range of valid values for the specified field.

All fields can be expressed as a long integer. This method returns an object that describes the valid range for that value. The value of this temporal object is used to enhance the accuracy of the returned range. If the date-time cannot return the range, because the field is unsupported or for some other reason, an exception will be thrown.

Note that the result only describes the minimum and maximum valid values and it is important not to read too much into them. For example, there could be values within the range that are invalid for the field.

Parameters
field the field to query the range for, not null
Returns
  • the range of valid values for the field, not null
Throws
DateTimeException if the range for the field cannot be obtained
UnsupportedTemporalTypeException if the field is not supported