* This is the base interface type for date, time and offset objects. * It is implemented by those classes that can provide information * as {@link TemporalField fields} or {@link TemporalQuery queries}. *
* Most date and time information can be represented as a number. * These are modeled using {@code TemporalField} with the number held using * a {@code long} to handle large values. Year, month and day-of-month are * simple examples of fields, but they also include instant and offsets. * See {@link ChronoField} for the standard set of fields. *
* Two pieces of date/time information cannot be represented by numbers, * the {@link Chronology chronology} and the {@link ZoneId time-zone}. * These can be accessed via {@link #query(TemporalQuery) queries} using * the static methods defined on {@link TemporalQueries}. *
* A sub-interface, {@link 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 {@code 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 {@link ChronoLocalDate} for a fuller discussion of the issues. * *
* This checks if the date-time can be queried for the specified field. * If false, then calling the {@link #range(TemporalField) range} and {@link #get(TemporalField) get} * methods will throw an exception. * *
* If the field is not a {@code ChronoField}, then the result of this method * is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)} * passing {@code this} as the argument. *
* Implementations must not alter this object. * * @param field the field to check, null returns false * @return true if this date-time can be queried for the field, false if not */ boolean isSupported(TemporalField field); /** * Gets the range of valid values for the specified field. *
* All fields can be expressed as a {@code 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. * *
* If the field is not a {@code ChronoField}, then the result of this method * is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessorl)} * passing {@code this} as the argument. *
* Implementations must not alter either this object. * * @param field the field to query the range for, not null * @return the range of valid values for the field, not null * @throws DateTimeException if the range for the field cannot be obtained */ ValueRange range(TemporalField field); /** * Gets the value of the specified field as an {@code int}. *
* This queries the date-time for the value for 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. * *
* If the field is not a {@code ChronoField}, then the result of this method * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} * passing {@code this} as the argument. *
* Implementations must not alter either this object. * * @param field the field to get, not null * @return the value for the field, within the valid range of values * @throws DateTimeException if a value for the field cannot be obtained * @throws DateTimeException if the range of valid values for the field exceeds an {@code int} * @throws DateTimeException if the value is outside the range of valid values for the field * @throws ArithmeticException if numeric overflow occurs */ int get(TemporalField field); /** * Gets the value of the specified field as a {@code long}. *
* This queries the date-time for the value for 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. * *
* If the field is not a {@code ChronoField}, then the result of this method * is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)} * passing {@code this} as the argument. *
* Implementations must not alter either this object. * * @param field the field to get, not null * @return the value for the field * @throws DateTimeException if a value for the field cannot be obtained * @throws ArithmeticException if numeric overflow occurs */ long getLong(TemporalField field); /** * 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 * {@code LocalDate::from} and {@code ZoneId::from}. * Further implementations are on {@link TemporalQueries}. * Queries may also be defined by applications. * *
* public <R> R query(TemporalQuery<R> type) {
* // only include an if statement if the implementation can return it
* if (query == TemporalQueries.zoneId()) return // the ZoneId
* if (query == TemporalQueries.chronology()) return // the Chrono
* if (query == TemporalQueries.precision()) return // the precision
* // call default method
* return super.query(query);
* }
*
*
* @param