45 *
46 * * Neither the name of JSR-310 nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 package java.time.temporal;
63
64 import java.time.DateTimeException;
65 import java.time.ZoneId;
66
67 /**
68 * Framework-level interface defining read-write access to a temporal object,
69 * such as a date, time, offset or some combination of these.
70 * <p>
71 * This is the base interface type for date, time and offset objects that
72 * are complete enough to be manipulated using plus and minus.
73 * It is implemented by those classes that can provide and manipulate information
74 * as {@linkplain TemporalField fields} or {@linkplain TemporalQuery queries}.
75 * See {@link TemporalAccessor} for the read-only version of this interface.
76 * <p>
77 * Most date and time information can be represented as a number.
78 * These are modeled using {@code TemporalField} with the number held using
79 * a {@code long} to handle large values. Year, month and day-of-month are
80 * simple examples of fields, but they also include instant and offsets.
81 * See {@link ChronoField} for the standard set of fields.
82 * <p>
83 * Two pieces of date/time information cannot be represented by numbers,
84 * the {@linkplain java.time.chrono.Chronology chronology} and the {@linkplain ZoneId time-zone}.
85 * These can be accessed via {@link #query(TemporalQuery) queries} using
86 * the static methods defined on {@link TemporalQuery}.
87 * <p>
88 * This interface is a framework-level interface that should not be widely
89 * used in application code. Instead, applications should create and pass
90 * around instances of concrete types, such as {@code LocalDate}.
91 * There are many reasons for this, part of which is that implementations
92 * of this interface may be in calendar systems other than ISO.
93 * See {@link java.time.chrono.ChronoLocalDate} for a fuller discussion of the issues.
94 *
95 * <h3>When to implement</h3>
96 * <p>
97 * A class should implement this interface if it meets three criteria:
98 * <p><ul>
99 * <li>it provides access to date/time/offset information, as per {@code TemporalAccessor}
100 * <li>the set of fields are contiguous from the largest to the smallest
101 * <li>the set of fields are complete, such that no other field is needed to define the
102 * valid range of values for the fields that are represented
103 * </ul><p>
104 * <p>
112 * validity. It is able to implement plus/minus correctly, by wrapping around the day.
113 * <li>{@code MonthDay}, the combination of month-of-year and day-of-month, does not implement
114 * this interface. While the combination is contiguous, from days to months within years,
115 * the combination does not have sufficient information to define the valid range of values
116 * for day-of-month. As such, it is unable to implement plus/minus correctly.
117 * <li>The combination day-of-week and day-of-month ("Friday the 13th") should not implement
118 * this interface. It does not represent a contiguous set of fields, as days to weeks overlaps
119 * days to months.
120 * </ul><p>
121 *
122 * @implSpec
123 * This interface places no restrictions on the mutability of implementations,
124 * however immutability is strongly recommended.
125 * All implementations must be {@link Comparable}.
126 *
127 * @since 1.8
128 */
129 public interface Temporal extends TemporalAccessor {
130
131 /**
132 * Returns an adjusted object of the same type as this object with the adjustment made.
133 * <p>
134 * This adjusts this date-time according to the rules of the specified adjuster.
135 * A simple adjuster might simply set the one of the fields, such as the year field.
136 * A more complex adjuster might set the date to the last day of the month.
137 * A selection of common adjustments is provided in {@link TemporalAdjuster}.
138 * These include finding the "last day of the month" and "next Wednesday".
139 * The adjuster is responsible for handling special cases, such as the varying
140 * lengths of month and leap years.
141 * <p>
142 * Some example code indicating how and why this method is used:
143 * <pre>
144 * date = date.with(Month.JULY); // most key classes implement TemporalAdjuster
145 * date = date.with(lastDayOfMonth()); // static import from Adjusters
146 * date = date.with(next(WEDNESDAY)); // static import from Adjusters and DayOfWeek
147 * </pre>
148 *
149 * @implSpec
150 * Implementations must not alter either this object.
151 * Instead, an adjusted copy of the original must be returned.
335 * @param amountToSubtract the amount of the specified unit to subtract, may be negative
336 * @param unit the unit of the period to subtract, not null
337 * @return an object of the same type with the specified period subtracted, not null
338 * @throws DateTimeException if the unit cannot be subtracted
339 * @throws UnsupportedTemporalTypeException if the unit is not supported
340 * @throws ArithmeticException if numeric overflow occurs
341 */
342 default Temporal minus(long amountToSubtract, TemporalUnit unit) {
343 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
344 }
345
346 //-----------------------------------------------------------------------
347 /**
348 * Calculates the amount of time until another temporal in terms of the specified unit.
349 * <p>
350 * This calculates the amount of time between two temporal objects
351 * of the same type in terms of a single {@code TemporalUnit}.
352 * The start and end points are {@code this} and the specified temporal.
353 * The result will be negative if the end is before the start.
354 * For example, the period in hours between two temporal objects can be
355 * calculated using {@code startTime.periodUntil(endTime, HOURS)}.
356 * <p>
357 * The calculation returns a whole number, representing the number of
358 * complete units between the two temporals.
359 * For example, the period in hours between the times 11:30 and 13:29
360 * will only be one hour as it is one minute short of two hours.
361 * <p>
362 * There are two equivalent ways of using this method.
363 * The first is to invoke this method directly.
364 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
365 * <pre>
366 * // these two lines are equivalent
367 * temporal = start.periodUntil(end, unit);
368 * temporal = unit.between(start, end);
369 * </pre>
370 * The choice should be made based on which makes the code more readable.
371 * <p>
372 * For example, this method allows the number of days between two dates to
373 * be calculated:
374 * <pre>
375 * long daysBetween = start.periodUntil(end, DAYS);
376 * // or alternatively
377 * long daysBetween = DAYS.between(start, end);
378 * </pre>
379 *
380 * @implSpec
381 * Implementations must begin by checking to ensure that the input temporal
382 * object is of the same observable type as the implementation.
383 * They must then perform the calculation for all instances of {@link ChronoUnit}.
384 * An {@code UnsupportedTemporalTypeException} must be thrown for {@code ChronoUnit}
385 * instances that are unsupported.
386 * <p>
387 * If the unit is not a {@code ChronoUnit}, then the result of this method
388 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
389 * passing {@code this} as the first argument and the input temporal as
390 * the second argument.
391 * <p>
392 * In summary, implementations must behave in a manner equivalent to this code:
393 * <pre>
394 * // check input temporal is the same type as this class
395 * if (unit instanceof ChronoUnit) {
396 * // if unit is supported, then calculate and return result
397 * // else throw UnsupportedTemporalTypeException for unsupported units
398 * }
399 * return unit.between(this, endTemporal);
400 * </pre>
401 * <p>
402 * Neither this object, nor the specified temporal, may be altered.
403 *
404 * @param endTemporal the end temporal, of the same type as this object, not null
405 * @param unit the unit to measure the amount in, not null
406 * @return the amount of time between this temporal object and the specified one
407 * in terms of the unit; positive if the specified object is later than this one,
408 * negative if it is earlier than this one
409 * @throws DateTimeException if the amount cannot be calculated
410 * @throws UnsupportedTemporalTypeException if the unit is not supported
411 * @throws ArithmeticException if numeric overflow occurs
412 */
413 long periodUntil(Temporal endTemporal, TemporalUnit unit);
414
415 }
|
45 *
46 * * Neither the name of JSR-310 nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 package java.time.temporal;
63
64 import java.time.DateTimeException;
65
66 /**
67 * Framework-level interface defining read-write access to a temporal object,
68 * such as a date, time, offset or some combination of these.
69 * <p>
70 * This is the base interface type for date, time and offset objects that
71 * are complete enough to be manipulated using plus and minus.
72 * It is implemented by those classes that can provide and manipulate information
73 * as {@linkplain TemporalField fields} or {@linkplain TemporalQuery queries}.
74 * See {@link TemporalAccessor} for the read-only version of this interface.
75 * <p>
76 * Most date and time information can be represented as a number.
77 * These are modeled using {@code TemporalField} with the number held using
78 * a {@code long} to handle large values. Year, month and day-of-month are
79 * simple examples of fields, but they also include instant and offsets.
80 * See {@link ChronoField} for the standard set of fields.
81 * <p>
82 * Two pieces of date/time information cannot be represented by numbers,
83 * the {@linkplain java.time.chrono.Chronology chronology} and the
84 * {@linkplain java.time.ZoneId time-zone}.
85 * These can be accessed via {@link #query(TemporalQuery) queries} using
86 * the static methods defined on {@link TemporalQuery}.
87 * <p>
88 * This interface is a framework-level interface that should not be widely
89 * used in application code. Instead, applications should create and pass
90 * around instances of concrete types, such as {@code LocalDate}.
91 * There are many reasons for this, part of which is that implementations
92 * of this interface may be in calendar systems other than ISO.
93 * See {@link java.time.chrono.ChronoLocalDate} for a fuller discussion of the issues.
94 *
95 * <h3>When to implement</h3>
96 * <p>
97 * A class should implement this interface if it meets three criteria:
98 * <p><ul>
99 * <li>it provides access to date/time/offset information, as per {@code TemporalAccessor}
100 * <li>the set of fields are contiguous from the largest to the smallest
101 * <li>the set of fields are complete, such that no other field is needed to define the
102 * valid range of values for the fields that are represented
103 * </ul><p>
104 * <p>
112 * validity. It is able to implement plus/minus correctly, by wrapping around the day.
113 * <li>{@code MonthDay}, the combination of month-of-year and day-of-month, does not implement
114 * this interface. While the combination is contiguous, from days to months within years,
115 * the combination does not have sufficient information to define the valid range of values
116 * for day-of-month. As such, it is unable to implement plus/minus correctly.
117 * <li>The combination day-of-week and day-of-month ("Friday the 13th") should not implement
118 * this interface. It does not represent a contiguous set of fields, as days to weeks overlaps
119 * days to months.
120 * </ul><p>
121 *
122 * @implSpec
123 * This interface places no restrictions on the mutability of implementations,
124 * however immutability is strongly recommended.
125 * All implementations must be {@link Comparable}.
126 *
127 * @since 1.8
128 */
129 public interface Temporal extends TemporalAccessor {
130
131 /**
132 * Checks if the specified unit is supported.
133 * <p>
134 * This checks if the specified unit can be added to, or subtracted from, this date-time.
135 * If false, then calling the {@link #plus(long, TemporalUnit)} and
136 * {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
137 *
138 * @implSpec
139 * Implementations must check and handle all units defined in {@link ChronoUnit}.
140 * If the unit is supported, then true must be returned, otherwise false must be returned.
141 * <p>
142 * If the field is not a {@code ChronoUnit}, then the result of this method
143 * is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
144 * passing {@code this} as the argument.
145 * <p>
146 * Implementations must ensure that no observable state is altered when this
147 * read-only method is invoked.
148 *
149 * @param unit the unit to check, null returns false
150 * @return true if the unit can be added/subtracted, false if not
151 */
152 boolean isSupported(TemporalUnit unit);
153
154 /**
155 * Returns an adjusted object of the same type as this object with the adjustment made.
156 * <p>
157 * This adjusts this date-time according to the rules of the specified adjuster.
158 * A simple adjuster might simply set the one of the fields, such as the year field.
159 * A more complex adjuster might set the date to the last day of the month.
160 * A selection of common adjustments is provided in {@link TemporalAdjuster}.
161 * These include finding the "last day of the month" and "next Wednesday".
162 * The adjuster is responsible for handling special cases, such as the varying
163 * lengths of month and leap years.
164 * <p>
165 * Some example code indicating how and why this method is used:
166 * <pre>
167 * date = date.with(Month.JULY); // most key classes implement TemporalAdjuster
168 * date = date.with(lastDayOfMonth()); // static import from Adjusters
169 * date = date.with(next(WEDNESDAY)); // static import from Adjusters and DayOfWeek
170 * </pre>
171 *
172 * @implSpec
173 * Implementations must not alter either this object.
174 * Instead, an adjusted copy of the original must be returned.
358 * @param amountToSubtract the amount of the specified unit to subtract, may be negative
359 * @param unit the unit of the period to subtract, not null
360 * @return an object of the same type with the specified period subtracted, not null
361 * @throws DateTimeException if the unit cannot be subtracted
362 * @throws UnsupportedTemporalTypeException if the unit is not supported
363 * @throws ArithmeticException if numeric overflow occurs
364 */
365 default Temporal minus(long amountToSubtract, TemporalUnit unit) {
366 return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
367 }
368
369 //-----------------------------------------------------------------------
370 /**
371 * Calculates the amount of time until another temporal in terms of the specified unit.
372 * <p>
373 * This calculates the amount of time between two temporal objects
374 * of the same type in terms of a single {@code TemporalUnit}.
375 * The start and end points are {@code this} and the specified temporal.
376 * The result will be negative if the end is before the start.
377 * For example, the period in hours between two temporal objects can be
378 * calculated using {@code startTime.until(endTime, HOURS)}.
379 * <p>
380 * The calculation returns a whole number, representing the number of
381 * complete units between the two temporals.
382 * For example, the period in hours between the times 11:30 and 13:29
383 * will only be one hour as it is one minute short of two hours.
384 * <p>
385 * There are two equivalent ways of using this method.
386 * The first is to invoke this method directly.
387 * The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
388 * <pre>
389 * // these two lines are equivalent
390 * temporal = start.until(end, unit);
391 * temporal = unit.between(start, end);
392 * </pre>
393 * The choice should be made based on which makes the code more readable.
394 * <p>
395 * For example, this method allows the number of days between two dates to
396 * be calculated:
397 * <pre>
398 * long daysBetween = start.until(end, DAYS);
399 * // or alternatively
400 * long daysBetween = DAYS.between(start, end);
401 * </pre>
402 *
403 * @implSpec
404 * Implementations must begin by checking to ensure that the input temporal
405 * object is of the same observable type as the implementation.
406 * They must then perform the calculation for all instances of {@link ChronoUnit}.
407 * An {@code UnsupportedTemporalTypeException} must be thrown for {@code ChronoUnit}
408 * instances that are unsupported.
409 * <p>
410 * If the unit is not a {@code ChronoUnit}, then the result of this method
411 * is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
412 * passing {@code this} as the first argument and the input temporal as
413 * the second argument.
414 * <p>
415 * In summary, implementations must behave in a manner equivalent to this code:
416 * <pre>
417 * // check input temporal is the same type as this class
418 * if (unit instanceof ChronoUnit) {
419 * // if unit is supported, then calculate and return result
420 * // else throw UnsupportedTemporalTypeException for unsupported units
421 * }
422 * return unit.between(this, endTemporal);
423 * </pre>
424 * <p>
425 * Implementations must ensure that no observable state is altered when this
426 * read-only method is invoked.
427 *
428 * @param endTemporal the end temporal, of the same type as this object, not null
429 * @param unit the unit to measure the amount in, not null
430 * @return the amount of time between this temporal object and the specified one
431 * in terms of the unit; positive if the specified object is later than this one,
432 * negative if it is earlier than this one
433 * @throws DateTimeException if the amount cannot be calculated
434 * @throws UnsupportedTemporalTypeException if the unit is not supported
435 * @throws ArithmeticException if numeric overflow occurs
436 */
437 long until(Temporal endTemporal, TemporalUnit unit);
438
439 }
|