001/*
002 *  Copyright 2001-2010 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.time;
017
018import org.joda.convert.FromString;
019import org.joda.convert.ToString;
020import org.joda.time.base.BaseSingleFieldPeriod;
021import org.joda.time.field.FieldUtils;
022import org.joda.time.format.ISOPeriodFormat;
023import org.joda.time.format.PeriodFormatter;
024
025/**
026 * An immutable time period representing a number of seconds.
027 * <p>
028 * <code>Seconds</code> is an immutable period that can only store seconds.
029 * It does not store years, months or hours for example. As such it is a
030 * type-safe way of representing a number of seconds in an application.
031 * <p>
032 * The number of seconds is set in the constructor, and may be queried using
033 * <code>getSeconds()</code>. Basic mathematical operations are provided -
034 * <code>plus()</code>, <code>minus()</code>, <code>multipliedBy()</code> and
035 * <code>dividedBy()</code>.
036 * <p>
037 * <code>Seconds</code> is thread-safe and immutable.
038 *
039 * @author Stephen Colebourne
040 * @since 1.4
041 */
042public final class Seconds extends BaseSingleFieldPeriod {
043
044    /** Constant representing zero seconds. */
045    public static final Seconds ZERO = new Seconds(0);
046    /** Constant representing one second. */
047    public static final Seconds ONE = new Seconds(1);
048    /** Constant representing two seconds. */
049    public static final Seconds TWO = new Seconds(2);
050    /** Constant representing three seconds. */
051    public static final Seconds THREE = new Seconds(3);
052    /** Constant representing the maximum number of seconds that can be stored in this object. */
053    public static final Seconds MAX_VALUE = new Seconds(Integer.MAX_VALUE);
054    /** Constant representing the minimum number of seconds that can be stored in this object. */
055    public static final Seconds MIN_VALUE = new Seconds(Integer.MIN_VALUE);
056
057    /** The paser to use for this class. */
058    private static final PeriodFormatter PARSER = ISOPeriodFormat.standard().withParseType(PeriodType.seconds());
059    /** Serialization version. */
060    private static final long serialVersionUID = 87525275727380862L;
061
062    //-----------------------------------------------------------------------
063    /**
064     * Obtains an instance of <code>Seconds</code> that may be cached.
065     * <code>Seconds</code> is immutable, so instances can be cached and shared.
066     * This factory method provides access to shared instances.
067     *
068     * @param seconds  the number of seconds to obtain an instance for
069     * @return the instance of Seconds
070     */
071    public static Seconds seconds(int seconds) {
072        switch (seconds) {
073            case 0:
074                return ZERO;
075            case 1:
076                return ONE;
077            case 2:
078                return TWO;
079            case 3:
080                return THREE;
081            case Integer.MAX_VALUE:
082                return MAX_VALUE;
083            case Integer.MIN_VALUE:
084                return MIN_VALUE;
085            default:
086                return new Seconds(seconds);
087        }
088    }
089
090    //-----------------------------------------------------------------------
091    /**
092     * Creates a <code>Seconds</code> representing the number of whole seconds
093     * between the two specified datetimes.
094     *
095     * @param start  the start instant, must not be null
096     * @param end  the end instant, must not be null
097     * @return the period in seconds
098     * @throws IllegalArgumentException if the instants are null or invalid
099     */
100    public static Seconds secondsBetween(ReadableInstant start, ReadableInstant end) {
101        int amount = BaseSingleFieldPeriod.between(start, end, DurationFieldType.seconds());
102        return Seconds.seconds(amount);
103    }
104
105    /**
106     * Creates a <code>Seconds</code> representing the number of whole seconds
107     * between the two specified partial datetimes.
108     * <p>
109     * The two partials must contain the same fields, for example you can specify
110     * two <code>LocalTime</code> objects.
111     *
112     * @param start  the start partial date, must not be null
113     * @param end  the end partial date, must not be null
114     * @return the period in seconds
115     * @throws IllegalArgumentException if the partials are null or invalid
116     */
117    public static Seconds secondsBetween(ReadablePartial start, ReadablePartial end) {
118        if (start instanceof LocalTime && end instanceof LocalTime)   {
119            Chronology chrono = DateTimeUtils.getChronology(start.getChronology());
120            int seconds = chrono.seconds().getDifference(
121                    ((LocalTime) end).getLocalMillis(), ((LocalTime) start).getLocalMillis());
122            return Seconds.seconds(seconds);
123        }
124        int amount = BaseSingleFieldPeriod.between(start, end, ZERO);
125        return Seconds.seconds(amount);
126    }
127
128    /**
129     * Creates a <code>Seconds</code> representing the number of whole seconds
130     * in the specified interval.
131     *
132     * @param interval  the interval to extract seconds from, null returns zero
133     * @return the period in seconds
134     * @throws IllegalArgumentException if the partials are null or invalid
135     */
136    public static Seconds secondsIn(ReadableInterval interval) {
137        if (interval == null)   {
138            return Seconds.ZERO;
139        }
140        int amount = BaseSingleFieldPeriod.between(interval.getStart(), interval.getEnd(), DurationFieldType.seconds());
141        return Seconds.seconds(amount);
142    }
143
144    /**
145     * Creates a new <code>Seconds</code> representing the number of complete
146     * standard length seconds in the specified period.
147     * <p>
148     * This factory method converts all fields from the period to hours using standardised
149     * durations for each field. Only those fields which have a precise duration in
150     * the ISO UTC chronology can be converted.
151     * <ul>
152     * <li>One week consists of 7 seconds.
153     * <li>One day consists of 24 hours.
154     * <li>One hour consists of 60 minutes.
155     * <li>One minute consists of 60 seconds.
156     * <li>One second consists of 1000 milliseconds.
157     * </ul>
158     * Months and Years are imprecise and periods containing these values cannot be converted.
159     *
160     * @param period  the period to get the number of hours from, null returns zero
161     * @return the period in seconds
162     * @throws IllegalArgumentException if the period contains imprecise duration values
163     */
164    public static Seconds standardSecondsIn(ReadablePeriod period) {
165        int amount = BaseSingleFieldPeriod.standardPeriodIn(period, DateTimeConstants.MILLIS_PER_SECOND);
166        return Seconds.seconds(amount);
167    }
168
169    /**
170     * Creates a new <code>Seconds</code> by parsing a string in the ISO8601 format 'PTnS'.
171     * <p>
172     * The parse will accept the full ISO syntax of PnYnMnWnDTnHnMnS however only the
173     * seconds component may be non-zero. If any other component is non-zero, an exception
174     * will be thrown.
175     *
176     * @param periodStr  the period string, null returns zero
177     * @return the period in seconds
178     * @throws IllegalArgumentException if the string format is invalid
179     */
180    @FromString
181    public static Seconds parseSeconds(String periodStr) {
182        if (periodStr == null) {
183            return Seconds.ZERO;
184        }
185        Period p = PARSER.parsePeriod(periodStr);
186        return Seconds.seconds(p.getSeconds());
187    }
188
189    //-----------------------------------------------------------------------
190    /**
191     * Creates a new instance representing a number of seconds.
192     * You should consider using the factory method {@link #seconds(int)}
193     * instead of the constructor.
194     *
195     * @param seconds  the number of seconds to represent
196     */
197    private Seconds(int seconds) {
198        super(seconds);
199    }
200
201    /**
202     * Resolves singletons.
203     * 
204     * @return the singleton instance
205     */
206    private Object readResolve() {
207        return Seconds.seconds(getValue());
208    }
209
210    //-----------------------------------------------------------------------
211    /**
212     * Gets the duration field type, which is <code>seconds</code>.
213     *
214     * @return the period type
215     */
216    public DurationFieldType getFieldType() {
217        return DurationFieldType.seconds();
218    }
219
220    /**
221     * Gets the period type, which is <code>seconds</code>.
222     *
223     * @return the period type
224     */
225    public PeriodType getPeriodType() {
226        return PeriodType.seconds();
227    }
228
229    //-----------------------------------------------------------------------
230    /**
231     * Converts this period in seconds to a period in weeks assuming a
232     * 7 day week, 24 hour day, 60 minute hour and 60 second minute.
233     * <p>
234     * This method allows you to convert between different types of period.
235     * However to achieve this it makes the assumption that all weeks are 7 days
236     * long, all days are 24 hours long, all hours are 60 minutes long and
237     * all minutes are 60 seconds long.
238     * This is not true when daylight savings time is considered, and may also
239     * not be true for some unusual chronologies. However, it is included as it
240     * is a useful operation for many applications and business rules.
241     * 
242     * @return a period representing the number of whole weeks for this number of seconds
243     */
244    public Weeks toStandardWeeks() {
245        return Weeks.weeks(getValue() / DateTimeConstants.SECONDS_PER_WEEK);
246    }
247
248    /**
249     * Converts this period in seconds to a period in days assuming a
250     * 24 hour day, 60 minute hour and 60 second minute.
251     * <p>
252     * This method allows you to convert between different types of period.
253     * However to achieve this it makes the assumption that all days are 24 hours
254     * long, all hours are 60 minutes long and all minutes are 60 seconds long.
255     * This is not true when daylight savings is considered and may also not
256     * be true for some unusual chronologies. However, it is included
257     * as it is a useful operation for many applications and business rules.
258     * 
259     * @return a period representing the number of days for this number of seconds
260     */
261    public Days toStandardDays() {
262        return Days.days(getValue() / DateTimeConstants.SECONDS_PER_DAY);
263    }
264
265    /**
266     * Converts this period in seconds to a period in hours assuming a
267     * 60 minute hour and 60 second minute.
268     * <p>
269     * This method allows you to convert between different types of period.
270     * However to achieve this it makes the assumption that all hours are
271     * 60 minutes long and all minutes are 60 seconds long.
272     * This may not be true for some unusual chronologies. However, it is included
273     * as it is a useful operation for many applications and business rules.
274     * 
275     * @return a period representing the number of hours for this number of seconds
276     */
277    public Hours toStandardHours() {
278        return Hours.hours(getValue() / DateTimeConstants.SECONDS_PER_HOUR);
279    }
280
281    /**
282     * Converts this period in seconds to a period in minutes assuming a
283     * 60 second minute.
284     * <p>
285     * This method allows you to convert between different types of period.
286     * However to achieve this it makes the assumption that all minutes are
287     * 60 seconds long.
288     * This may not be true for some unusual chronologies. However, it is included
289     * as it is a useful operation for many applications and business rules.
290     * 
291     * @return a period representing the number of minutes for this number of seconds
292     */
293    public Minutes toStandardMinutes() {
294        return Minutes.minutes(getValue() / DateTimeConstants.SECONDS_PER_MINUTE);
295    }
296
297    //-----------------------------------------------------------------------
298    /**
299     * Converts this period in seconds to a duration in milliseconds assuming a
300     * 24 hour day, 60 minute hour and 60 second minute.
301     * <p>
302     * This method allows you to convert from a period to a duration.
303     * However to achieve this it makes the assumption that all seconds are 24 hours
304     * long, all hours are 60 minutes and all minutes are 60 seconds.
305     * This is not true when daylight savings time is considered, and may also
306     * not be true for some unusual chronologies. However, it is included as it
307     * is a useful operation for many applications and business rules.
308     * 
309     * @return a duration equivalent to this number of seconds
310     */
311    public Duration toStandardDuration() {
312        long seconds = getValue();  // assign to a long
313        return new Duration(seconds * DateTimeConstants.MILLIS_PER_SECOND);
314    }
315
316    //-----------------------------------------------------------------------
317    /**
318     * Gets the number of seconds that this period represents.
319     *
320     * @return the number of seconds in the period
321     */
322    public int getSeconds() {
323        return getValue();
324    }
325
326    //-----------------------------------------------------------------------
327    /**
328     * Returns a new instance with the specified number of seconds added.
329     * <p>
330     * This instance is immutable and unaffected by this method call.
331     *
332     * @param seconds  the amount of seconds to add, may be negative
333     * @return the new period plus the specified number of seconds
334     * @throws ArithmeticException if the result overflows an int
335     */
336    public Seconds plus(int seconds) {
337        if (seconds == 0) {
338            return this;
339        }
340        return Seconds.seconds(FieldUtils.safeAdd(getValue(), seconds));
341    }
342
343    /**
344     * Returns a new instance with the specified number of seconds added.
345     * <p>
346     * This instance is immutable and unaffected by this method call.
347     *
348     * @param seconds  the amount of seconds to add, may be negative, null means zero
349     * @return the new period plus the specified number of seconds
350     * @throws ArithmeticException if the result overflows an int
351     */
352    public Seconds plus(Seconds seconds) {
353        if (seconds == null) {
354            return this;
355        }
356        return plus(seconds.getValue());
357    }
358
359    //-----------------------------------------------------------------------
360    /**
361     * Returns a new instance with the specified number of seconds taken away.
362     * <p>
363     * This instance is immutable and unaffected by this method call.
364     *
365     * @param seconds  the amount of seconds to take away, may be negative
366     * @return the new period minus the specified number of seconds
367     * @throws ArithmeticException if the result overflows an int
368     */
369    public Seconds minus(int seconds) {
370        return plus(FieldUtils.safeNegate(seconds));
371    }
372
373    /**
374     * Returns a new instance with the specified number of seconds taken away.
375     * <p>
376     * This instance is immutable and unaffected by this method call.
377     *
378     * @param seconds  the amount of seconds to take away, may be negative, null means zero
379     * @return the new period minus the specified number of seconds
380     * @throws ArithmeticException if the result overflows an int
381     */
382    public Seconds minus(Seconds seconds) {
383        if (seconds == null) {
384            return this;
385        }
386        return minus(seconds.getValue());
387    }
388
389    //-----------------------------------------------------------------------
390    /**
391     * Returns a new instance with the seconds multiplied by the specified scalar.
392     * <p>
393     * This instance is immutable and unaffected by this method call.
394     *
395     * @param scalar  the amount to multiply by, may be negative
396     * @return the new period multiplied by the specified scalar
397     * @throws ArithmeticException if the result overflows an int
398     */
399    public Seconds multipliedBy(int scalar) {
400        return Seconds.seconds(FieldUtils.safeMultiply(getValue(), scalar));
401    }
402
403    /**
404     * Returns a new instance with the seconds divided by the specified divisor.
405     * The calculation uses integer division, thus 3 divided by 2 is 1.
406     * <p>
407     * This instance is immutable and unaffected by this method call.
408     *
409     * @param divisor  the amount to divide by, may be negative
410     * @return the new period divided by the specified divisor
411     * @throws ArithmeticException if the divisor is zero
412     */
413    public Seconds dividedBy(int divisor) {
414        if (divisor == 1) {
415            return this;
416        }
417        return Seconds.seconds(getValue() / divisor);
418    }
419
420    //-----------------------------------------------------------------------
421    /**
422     * Returns a new instance with the seconds value negated.
423     *
424     * @return the new period with a negated value
425     * @throws ArithmeticException if the result overflows an int
426     */
427    public Seconds negated() {
428        return Seconds.seconds(FieldUtils.safeNegate(getValue()));
429    }
430
431    //-----------------------------------------------------------------------
432    /**
433     * Is this seconds instance greater than the specified number of seconds.
434     *
435     * @param other  the other period, null means zero
436     * @return true if this seconds instance is greater than the specified one
437     */
438    public boolean isGreaterThan(Seconds other) {
439        if (other == null) {
440            return getValue() > 0;
441        }
442        return getValue() > other.getValue();
443    }
444
445    /**
446     * Is this seconds instance less than the specified number of seconds.
447     *
448     * @param other  the other period, null means zero
449     * @return true if this seconds instance is less than the specified one
450     */
451    public boolean isLessThan(Seconds other) {
452        if (other == null) {
453            return getValue() < 0;
454        }
455        return getValue() < other.getValue();
456    }
457
458    //-----------------------------------------------------------------------
459    /**
460     * Gets this instance as a String in the ISO8601 duration format.
461     * <p>
462     * For example, "PT4S" represents 4 seconds.
463     *
464     * @return the value as an ISO8601 string
465     */
466    @ToString
467    public String toString() {
468        return "PT" + String.valueOf(getValue()) + "S";
469    }
470
471}