Java example source code file (BaseDateTimeField.java)
The BaseDateTimeField.java Java example source code/*
* Copyright 2001-2005 Stephen Colebourne
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.joda.time.field;
import java.util.Locale;
import org.joda.time.DateTimeField;
import org.joda.time.DateTimeFieldType;
import org.joda.time.DurationField;
import org.joda.time.IllegalFieldValueException;
import org.joda.time.ReadablePartial;
/**
* BaseDateTimeField provides the common behaviour for DateTimeField
* implementations.
* <p>
* This class should generally not be used directly by API users. The
* DateTimeField class should be used when different kinds of DateTimeField
* objects are to be referenced.
* <p>
* BaseDateTimeField is thread-safe and immutable, and its subclasses must
* be as well.
*
* @author Brian S O'Neill
* @since 1.0
* @see DecoratedDateTimeField
*/
public abstract class BaseDateTimeField extends DateTimeField {
/** The field type. */
private final DateTimeFieldType iType;
/**
* Constructor.
*/
protected BaseDateTimeField(DateTimeFieldType type) {
super();
if (type == null) {
throw new IllegalArgumentException("The type must not be null");
}
iType = type;
}
public final DateTimeFieldType getType() {
return iType;
}
public final String getName() {
return iType.getName();
}
/**
* @return true always
*/
public final boolean isSupported() {
return true;
}
// Main access API
//------------------------------------------------------------------------
/**
* Get the value of this field from the milliseconds.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @return the value of the field, in the units of the field
*/
public abstract int get(long instant);
//-----------------------------------------------------------------------
/**
* Get the human-readable, text value of this field from the milliseconds.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns getAsText(get(instant), locale).
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @param locale the locale to use for selecting a text symbol, null means default
* @return the text value of the field
*/
public String getAsText(long instant, Locale locale) {
return getAsText(get(instant), locale);
}
/**
* Get the human-readable, text value of this field from the milliseconds.
* <p>
* The default implementation calls {@link #getAsText(long, Locale)}.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @return the text value of the field
*/
public final String getAsText(long instant) {
return getAsText(instant, null);
}
/**
* Get the human-readable, text value of this field from a partial instant.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns getAsText(fieldValue, locale).
*
* @param partial the partial instant to query
* @param fieldValue the field value of this field, provided for performance
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public String getAsText(ReadablePartial partial, int fieldValue, Locale locale) {
return getAsText(fieldValue, locale);
}
/**
* Get the human-readable, text value of this field from a partial instant.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation calls {@link ReadablePartial#get(DateTimeFieldType)}
* and {@link #getAsText(ReadablePartial, int, Locale)}.
*
* @param partial the partial instant to query
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public final String getAsText(ReadablePartial partial, Locale locale) {
return getAsText(partial, partial.get(getType()), locale);
}
/**
* Get the human-readable, text value of this field from the field value.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns Integer.toString(get(instant)).
* <p>
* Note: subclasses that override this method should also override
* getMaximumTextLength.
*
* @param fieldValue the numeric value to convert to text
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public String getAsText(int fieldValue, Locale locale) {
return Integer.toString(fieldValue);
}
//-----------------------------------------------------------------------
/**
* Get the human-readable, short text value of this field from the milliseconds.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns getAsShortText(get(instant), locale).
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @param locale the locale to use for selecting a text symbol, null means default
* @return the text value of the field
*/
public String getAsShortText(long instant, Locale locale) {
return getAsShortText(get(instant), locale);
}
/**
* Get the human-readable, short text value of this field from the milliseconds.
* <p>
* The default implementation calls {@link #getAsShortText(long, Locale)}.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @return the text value of the field
*/
public final String getAsShortText(long instant) {
return getAsShortText(instant, null);
}
/**
* Get the human-readable, short text value of this field from a partial instant.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns getAsShortText(fieldValue, locale).
*
* @param partial the partial instant to query
* @param fieldValue the field value of this field, provided for performance
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public String getAsShortText(ReadablePartial partial, int fieldValue, Locale locale) {
return getAsShortText(fieldValue, locale);
}
/**
* Get the human-readable, short text value of this field from a partial instant.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation calls {@link ReadablePartial#get(DateTimeFieldType)}
* and {@link #getAsText(ReadablePartial, int, Locale)}.
*
* @param partial the partial instant to query
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public final String getAsShortText(ReadablePartial partial, Locale locale) {
return getAsShortText(partial, partial.get(getType()), locale);
}
/**
* Get the human-readable, short text value of this field from the field value.
* If the specified locale is null, the default locale is used.
* <p>
* The default implementation returns getAsText(fieldValue, locale).
* <p>
* Note: subclasses that override this method should also override
* getMaximumShortTextLength.
*
* @param fieldValue the numeric value to convert to text
* @param locale the locale to use for selecting a text symbol, null for default
* @return the text value of the field
*/
public String getAsShortText(int fieldValue, Locale locale) {
return getAsText(fieldValue, locale);
}
//-----------------------------------------------------------------------
/**
* Adds a value (which may be negative) to the instant value,
* overflowing into larger fields if necessary.
* <p>
* The value will be added to this field. If the value is too large to be
* added solely to this field, larger fields will increase as required.
* Smaller fields should be unaffected, except where the result would be
* an invalid value for a smaller field. In this case the smaller field is
* adjusted to be in range.
* <p>
* For example, in the ISO chronology:<br>
* 2000-08-20 add six months is 2001-02-20<br>
* 2000-08-20 add twenty months is 2002-04-20<br>
* 2000-08-20 add minus nine months is 1999-11-20<br>
* 2001-01-31 add one month is 2001-02-28<br>
* 2001-01-31 add two months is 2001-03-31<br>
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to add to
* @param value the value to add, in the units of the field
* @return the updated milliseconds
*/
public long add(long instant, int value) {
return getDurationField().add(instant, value);
}
/**
* Adds a value (which may be negative) to the instant value,
* overflowing into larger fields if necessary.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to add to
* @param value the long value to add, in the units of the field
* @return the updated milliseconds
* @throws IllegalArgumentException if value is too large
* @see #add(long,int)
*/
public long add(long instant, long value) {
return getDurationField().add(instant, value);
}
/**
* Adds a value (which may be negative) to the partial instant,
* throwing an exception if the maximum size of the instant is reached.
* <p>
* The value will be added to this field, overflowing into larger fields
* if necessary. Smaller fields should be unaffected, except where the
* result would be an invalid value for a smaller field. In this case the
* smaller field is adjusted to be in range.
* <p>
* Partial instants only contain some fields. This may result in a maximum
* possible value, such as TimeOfDay being limited to 23:59:59:999. If this
* limit is breached by the add an exception is thrown.
* <p>
* For example, in the ISO chronology:<br>
* 2000-08-20 add six months is 2000-02-20<br>
* 2000-08-20 add twenty months is 2000-04-20<br>
* 2000-08-20 add minus nine months is 2000-11-20<br>
* 2001-01-31 add one month is 2001-02-28<br>
* 2001-01-31 add two months is 2001-03-31<br>
*
* @param instant the partial instant
* @param fieldIndex the index of this field in the partial
* @param values the values of the partial instant which should be updated
* @param valueToAdd the value to add, in the units of the field
* @return the passed in values
* @throws IllegalArgumentException if the value is invalid or the maximum instant is reached
*/
public int[] add(ReadablePartial instant, int fieldIndex, int[] values, int valueToAdd) {
if (valueToAdd == 0) {
return values;
}
// there are more efficient algorithms than this (especially for time only fields)
// trouble is when dealing with days and months, so we use this technique of
// adding/removing one from the larger field at a time
DateTimeField nextField = null;
while (valueToAdd > 0) {
int max = getMaximumValue(instant, values);
long proposed = values[fieldIndex] + valueToAdd;
if (proposed <= max) {
values[fieldIndex] = (int) proposed;
break;
}
if (nextField == null) {
if (fieldIndex == 0) {
throw new IllegalArgumentException("Maximum value exceeded for add");
}
nextField = instant.getField(fieldIndex - 1);
// test only works if this field is UTC (ie. local)
if (getRangeDurationField().getType() != nextField.getDurationField().getType()) {
throw new IllegalArgumentException("Fields invalid for add");
}
}
valueToAdd -= (max + 1) - values[fieldIndex]; // reduce the amount to add
values = nextField.add(instant, fieldIndex - 1, values, 1); // add 1 to next bigger field
values[fieldIndex] = getMinimumValue(instant, values); // reset this field to zero
}
while (valueToAdd < 0) {
int min = getMinimumValue(instant, values);
long proposed = values[fieldIndex] + valueToAdd;
if (proposed >= min) {
values[fieldIndex] = (int) proposed;
break;
}
if (nextField == null) {
if (fieldIndex == 0) {
throw new IllegalArgumentException("Maximum value exceeded for add");
}
nextField = instant.getField(fieldIndex - 1);
if (getRangeDurationField().getType() != nextField.getDurationField().getType()) {
throw new IllegalArgumentException("Fields invalid for add");
}
}
valueToAdd -= (min - 1) - values[fieldIndex]; // reduce the amount to add
values = nextField.add(instant, fieldIndex - 1, values, -1); // subtract 1 from next bigger field
values[fieldIndex] = getMaximumValue(instant, values); // reset this field to max value
}
return set(instant, fieldIndex, values, values[fieldIndex]); // adjusts smaller fields
}
/**
* Adds a value (which may be negative) to the partial instant,
* wrapping the whole partial if the maximum size of the partial is reached.
* <p>
* The value will be added to this field, overflowing into larger fields
* if necessary. Smaller fields should be unaffected, except where the
* result would be an invalid value for a smaller field. In this case the
* smaller field is adjusted to be in range.
* <p>
* Partial instants only contain some fields. This may result in a maximum
* possible value, such as TimeOfDay normally being limited to 23:59:59:999.
* If ths limit is reached by the addition, this method will wrap back to
* 00:00:00.000. In fact, you would generally only use this method for
* classes that have a limitation such as this.
* <p>
* For example, in the ISO chronology:<br>
* 10:20:30 add 20 minutes is 10:40:30<br>
* 10:20:30 add 45 minutes is 11:05:30<br>
* 10:20:30 add 16 hours is 02:20:30<br>
*
* @param instant the partial instant
* @param fieldIndex the index of this field in the partial
* @param values the values of the partial instant which should be updated
* @param valueToAdd the value to add, in the units of the field
* @return the passed in values
* @throws IllegalArgumentException if the value is invalid or the maximum instant is reached
*/
public int[] addWrapPartial(ReadablePartial instant, int fieldIndex, int[] values, int valueToAdd) {
if (valueToAdd == 0) {
return values;
}
// there are more efficient algorithms than this (especially for time only fields)
// trouble is when dealing with days and months, so we use this technique of
// adding/removing one from the larger field at a time
DateTimeField nextField = null;
while (valueToAdd > 0) {
int max = getMaximumValue(instant, values);
long proposed = values[fieldIndex] + valueToAdd;
if (proposed <= max) {
values[fieldIndex] = (int) proposed;
break;
}
if (nextField == null) {
if (fieldIndex == 0) {
valueToAdd -= (max + 1) - values[fieldIndex];
values[fieldIndex] = getMinimumValue(instant, values);
continue;
}
nextField = instant.getField(fieldIndex - 1);
// test only works if this field is UTC (ie. local)
if (getRangeDurationField().getType() != nextField.getDurationField().getType()) {
throw new IllegalArgumentException("Fields invalid for add");
}
}
valueToAdd -= (max + 1) - values[fieldIndex]; // reduce the amount to add
values = nextField.addWrapPartial(instant, fieldIndex - 1, values, 1); // add 1 to next bigger field
values[fieldIndex] = getMinimumValue(instant, values); // reset this field to zero
}
while (valueToAdd < 0) {
int min = getMinimumValue(instant, values);
long proposed = values[fieldIndex] + valueToAdd;
if (proposed >= min) {
values[fieldIndex] = (int) proposed;
break;
}
if (nextField == null) {
if (fieldIndex == 0) {
valueToAdd -= (min - 1) - values[fieldIndex];
values[fieldIndex] = getMaximumValue(instant, values);
continue;
}
nextField = instant.getField(fieldIndex - 1);
if (getRangeDurationField().getType() != nextField.getDurationField().getType()) {
throw new IllegalArgumentException("Fields invalid for add");
}
}
valueToAdd -= (min - 1) - values[fieldIndex]; // reduce the amount to add
values = nextField.addWrapPartial(instant, fieldIndex - 1, values, -1); // subtract 1 from next bigger field
values[fieldIndex] = getMaximumValue(instant, values); // reset this field to max value
}
return set(instant, fieldIndex, values, values[fieldIndex]); // adjusts smaller fields
}
/**
* Adds a value (which may be negative) to the instant value,
* wrapping within this field.
* <p>
* The value will be added to this field. If the value is too large to be
* added solely to this field then it wraps. Larger fields are always
* unaffected. Smaller fields should be unaffected, except where the
* result would be an invalid value for a smaller field. In this case the
* smaller field is adjusted to be in range.
* <p>
* For example, in the ISO chronology:<br>
* 2000-08-20 addWrapField six months is 2000-02-20<br>
* 2000-08-20 addWrapField twenty months is 2000-04-20<br>
* 2000-08-20 addWrapField minus nine months is 2000-11-20<br>
* 2001-01-31 addWrapField one month is 2001-02-28<br>
* 2001-01-31 addWrapField two months is 2001-03-31<br>
* <p>
* The default implementation internally calls set. Subclasses are
* encouraged to provide a more efficient implementation.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to add to
* @param value the value to add, in the units of the field
* @return the updated milliseconds
*/
public long addWrapField(long instant, int value) {
int current = get(instant);
int wrapped = FieldUtils.getWrappedValue
(current, value, getMinimumValue(instant), getMaximumValue(instant));
return set(instant, wrapped);
}
/**
* Adds a value (which may be negative) to the partial instant,
* wrapping within this field.
* <p>
* The value will be added to this field. If the value is too large to be
* added solely to this field then it wraps. Larger fields are always
* unaffected. Smaller fields should be unaffected, except where the
* result would be an invalid value for a smaller field. In this case the
* smaller field is adjusted to be in range.
* <p>
* For example, in the ISO chronology:<br>
* 2000-08-20 addWrapField six months is 2000-02-20<br>
* 2000-08-20 addWrapField twenty months is 2000-04-20<br>
* 2000-08-20 addWrapField minus nine months is 2000-11-20<br>
* 2001-01-31 addWrapField one month is 2001-02-28<br>
* 2001-01-31 addWrapField two months is 2001-03-31<br>
* <p>
* The default implementation internally calls set. Subclasses are
* encouraged to provide a more efficient implementation.
*
* @param instant the partial instant
* @param fieldIndex the index of this field in the instant
* @param values the values of the partial instant which should be updated
* @param valueToAdd the value to add, in the units of the field
* @return the passed in values
* @throws IllegalArgumentException if the value is invalid
*/
public int[] addWrapField(ReadablePartial instant, int fieldIndex, int[] values, int valueToAdd) {
int current = values[fieldIndex];
int wrapped = FieldUtils.getWrappedValue
(current, valueToAdd, getMinimumValue(instant), getMaximumValue(instant));
return set(instant, fieldIndex, values, wrapped); // adjusts smaller fields
}
//-----------------------------------------------------------------------
/**
* Computes the difference between two instants, as measured in the units
* of this field. Any fractional units are dropped from the result. Calling
* getDifference reverses the effect of calling add. In the following code:
*
* <pre>
* long instant = ...
* int v = ...
* int age = getDifference(add(instant, v), instant);
* </pre>
*
* The value 'age' is the same as the value 'v'.
*
* @param minuendInstant the milliseconds from 1970-01-01T00:00:00Z to
* subtract from
* @param subtrahendInstant the milliseconds from 1970-01-01T00:00:00Z to
* subtract off the minuend
* @return the difference in the units of this field
*/
public int getDifference(long minuendInstant, long subtrahendInstant) {
return getDurationField().getDifference(minuendInstant, subtrahendInstant);
}
/**
* Computes the difference between two instants, as measured in the units
* of this field. Any fractional units are dropped from the result. Calling
* getDifference reverses the effect of calling add. In the following code:
*
* <pre>
* long instant = ...
* long v = ...
* long age = getDifferenceAsLong(add(instant, v), instant);
* </pre>
*
* The value 'age' is the same as the value 'v'.
*
* @param minuendInstant the milliseconds from 1970-01-01T00:00:00Z to
* subtract from
* @param subtrahendInstant the milliseconds from 1970-01-01T00:00:00Z to
* subtract off the minuend
* @return the difference in the units of this field
*/
public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
return getDurationField().getDifferenceAsLong(minuendInstant, subtrahendInstant);
}
/**
* Sets a value in the milliseconds supplied.
* <p>
* The value of this field will be set.
* If the value is invalid, an exception if thrown.
* <p>
* If setting this field would make other fields invalid, then those fields
* may be changed. For example if the current date is the 31st January, and
* the month is set to February, the day would be invalid. Instead, the day
* would be changed to the closest value - the 28th/29th February as appropriate.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to set in
* @param value the value to set, in the units of the field
* @return the updated milliseconds
* @throws IllegalArgumentException if the value is invalid
*/
public abstract long set(long instant, int value);
/**
* Sets a value using the specified partial instant.
* <p>
* The value of this field (specified by the index) will be set.
* If the value is invalid, an exception if thrown.
* <p>
* If setting this field would make other fields invalid, then those fields
* may be changed. For example if the current date is the 31st January, and
* the month is set to February, the day would be invalid. Instead, the day
* would be changed to the closest value - the 28th/29th February as appropriate.
*
* @param partial the partial instant
* @param fieldIndex the index of this field in the instant
* @param values the values to update
* @param newValue the value to set, in the units of the field
* @return the updated values
* @throws IllegalArgumentException if the value is invalid
*/
public int[] set(ReadablePartial partial, int fieldIndex, int[] values, int newValue) {
FieldUtils.verifyValueBounds(this, newValue, getMinimumValue(partial, values), getMaximumValue(partial, values));
values[fieldIndex] = newValue;
// may need to adjust smaller fields
for (int i = fieldIndex + 1; i < partial.size(); i++) {
DateTimeField field = partial.getField(i);
if (values[i] > field.getMaximumValue(partial, values)) {
values[i] = field.getMaximumValue(partial, values);
}
if (values[i] < field.getMinimumValue(partial, values)) {
values[i] = field.getMinimumValue(partial, values);
}
}
return values;
}
/**
* Sets a value in the milliseconds supplied from a human-readable, text value.
* If the specified locale is null, the default locale is used.
* <p>
* This implementation uses <code>convertText(String, Locale) and
* {@link #set(long, int)}.
* <p>
* Note: subclasses that override this method should also override
* getAsText.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to set in
* @param text the text value to set
* @param locale the locale to use for selecting a text symbol, null for default
* @return the updated milliseconds
* @throws IllegalArgumentException if the text value is invalid
*/
public long set(long instant, String text, Locale locale) {
int value = convertText(text, locale);
return set(instant, value);
}
/**
* Sets a value in the milliseconds supplied from a human-readable, text value.
* <p>
* This implementation uses {@link #set(long, String, Locale)}.
* <p>
* Note: subclasses that override this method should also override getAsText.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to set in
* @param text the text value to set
* @return the updated milliseconds
* @throws IllegalArgumentException if the text value is invalid
*/
public final long set(long instant, String text) {
return set(instant, text, null);
}
/**
* Sets a value in the milliseconds supplied from a human-readable, text value.
* If the specified locale is null, the default locale is used.
* <p>
* This implementation uses <code>convertText(String, Locale) and
* {@link #set(ReadablePartial, int, int[], int)}.
*
* @param instant the partial instant
* @param fieldIndex the index of this field in the instant
* @param values the values of the partial instant which should be updated
* @param text the text value to set
* @param locale the locale to use for selecting a text symbol, null for default
* @return the passed in values
* @throws IllegalArgumentException if the text value is invalid
*/
public int[] set(ReadablePartial instant, int fieldIndex, int[] values, String text, Locale locale) {
int value = convertText(text, locale);
return set(instant, fieldIndex, values, value);
}
/**
* Convert the specified text and locale into a value.
*
* @param text the text to convert
* @param locale the locale to convert using
* @return the value extracted from the text
* @throws IllegalArgumentException if the text is invalid
*/
protected int convertText(String text, Locale locale) {
try {
return Integer.parseInt(text);
} catch (NumberFormatException ex) {
throw new IllegalFieldValueException(getType(), text);
}
}
// Extra information API
//------------------------------------------------------------------------
/**
* Returns the duration per unit value of this field. For example, if this
* field represents "hour of day", then the unit duration is an hour.
*
* @return the duration of this field, or UnsupportedDurationField if field
* has no duration
*/
public abstract DurationField getDurationField();
/**
* Returns the range duration of this field. For example, if this field
* represents "hour of day", then the range duration is a day.
*
* @return the range duration of this field, or null if field has no range
*/
public abstract DurationField getRangeDurationField();
/**
* Returns whether this field is 'leap' for the specified instant.
* <p>
* For example, a leap year would return true, a non leap year would return
* false.
* <p>
* This implementation returns false.
*
* @return true if the field is 'leap'
*/
public boolean isLeap(long instant) {
return false;
}
/**
* Gets the amount by which this field is 'leap' for the specified instant.
* <p>
* For example, a leap year would return one, a non leap year would return
* zero.
* <p>
* This implementation returns zero.
*/
public int getLeapAmount(long instant) {
return 0;
}
/**
* If this field were to leap, then it would be in units described by the
* returned duration. If this field doesn't ever leap, null is returned.
* <p>
* This implementation returns null.
*/
public DurationField getLeapDurationField() {
return null;
}
/**
* Get the minimum allowable value for this field.
*
* @return the minimum valid value for this field, in the units of the
* field
*/
public abstract int getMinimumValue();
/**
* Get the minimum value for this field evaluated at the specified time.
* <p>
* This implementation returns the same as {@link #getMinimumValue()}.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @return the minimum value for this field, in the units of the field
*/
public int getMinimumValue(long instant) {
return getMinimumValue();
}
/**
* Get the minimum value for this field evaluated at the specified instant.
* <p>
* This implementation returns the same as {@link #getMinimumValue()}.
*
* @param instant the partial instant to query
* @return the minimum value for this field, in the units of the field
*/
public int getMinimumValue(ReadablePartial instant) {
return getMinimumValue();
}
/**
* Get the minimum value for this field using the partial instant and
* the specified values.
* <p>
* This implementation returns the same as {@link #getMinimumValue(ReadablePartial)}.
*
* @param instant the partial instant to query
* @param values the values to use
* @return the minimum value for this field, in the units of the field
*/
public int getMinimumValue(ReadablePartial instant, int[] values) {
return getMinimumValue(instant);
}
/**
* Get the maximum allowable value for this field.
*
* @return the maximum valid value for this field, in the units of the
* field
*/
public abstract int getMaximumValue();
/**
* Get the maximum value for this field evaluated at the specified time.
* <p>
* This implementation returns the same as {@link #getMaximumValue()}.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to query
* @return the maximum value for this field, in the units of the field
*/
public int getMaximumValue(long instant) {
return getMaximumValue();
}
/**
* Get the maximum value for this field evaluated at the specified instant.
* <p>
* This implementation returns the same as {@link #getMaximumValue()}.
*
* @param instant the partial instant to query
* @return the maximum value for this field, in the units of the field
*/
public int getMaximumValue(ReadablePartial instant) {
return getMaximumValue();
}
/**
* Get the maximum value for this field using the partial instant and
* the specified values.
* <p>
* This implementation returns the same as {@link #getMaximumValue(ReadablePartial)}.
*
* @param instant the partial instant to query
* @param values the values to use
* @return the maximum value for this field, in the units of the field
*/
public int getMaximumValue(ReadablePartial instant, int[] values) {
return getMaximumValue(instant);
}
/**
* Get the maximum text value for this field. The default implementation
* returns the equivalent of Integer.toString(getMaximumValue()).length().
*
* @param locale the locale to use for selecting a text symbol
* @return the maximum text length
*/
public int getMaximumTextLength(Locale locale) {
int max = getMaximumValue();
if (max >= 0) {
if (max < 10) {
return 1;
} else if (max < 100) {
return 2;
} else if (max < 1000) {
return 3;
}
}
return Integer.toString(max).length();
}
/**
* Get the maximum short text value for this field. The default
* implementation returns getMaximumTextLength().
*
* @param locale the locale to use for selecting a text symbol
* @return the maximum short text length
*/
public int getMaximumShortTextLength(Locale locale) {
return getMaximumTextLength(locale);
}
// Calculation API
//------------------------------------------------------------------------
/**
* Round to the lowest whole unit of this field. After rounding, the value
* of this field and all fields of a higher magnitude are retained. The
* fractional millis that cannot be expressed in whole increments of this
* field are set to minimum.
* <p>
* For example, a datetime of 2002-11-02T23:34:56.789, rounded to the
* lowest whole hour is 2002-11-02T23:00:00.000.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to round
* @return rounded milliseconds
*/
public abstract long roundFloor(long instant);
/**
* Round to the highest whole unit of this field. The value of this field
* and all fields of a higher magnitude may be incremented in order to
* achieve this result. The fractional millis that cannot be expressed in
* whole increments of this field are set to minimum.
* <p>
* For example, a datetime of 2002-11-02T23:34:56.789, rounded to the
* highest whole hour is 2002-11-03T00:00:00.000.
* <p>
* The default implementation calls roundFloor, and if the instant is
* modified as a result, adds one field unit. Subclasses are encouraged to
* provide a more efficient implementation.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to round
* @return rounded milliseconds
*/
public long roundCeiling(long instant) {
long newInstant = roundFloor(instant);
if (newInstant != instant) {
instant = add(newInstant, 1);
}
return instant;
}
/**
* Round to the nearest whole unit of this field. If the given millisecond
* value is closer to the floor or is exactly halfway, this function
* behaves like roundFloor. If the millisecond value is closer to the
* ceiling, this function behaves like roundCeiling.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to round
* @return rounded milliseconds
*/
public long roundHalfFloor(long instant) {
long floor = roundFloor(instant);
long ceiling = roundCeiling(instant);
long diffFromFloor = instant - floor;
long diffToCeiling = ceiling - instant;
if (diffFromFloor <= diffToCeiling) {
// Closer to the floor, or halfway - round floor
return floor;
} else {
return ceiling;
}
}
/**
* Round to the nearest whole unit of this field. If the given millisecond
* value is closer to the floor, this function behaves like roundFloor. If
* the millisecond value is closer to the ceiling or is exactly halfway,
* this function behaves like roundCeiling.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to round
* @return rounded milliseconds
*/
public long roundHalfCeiling(long instant) {
long floor = roundFloor(instant);
long ceiling = roundCeiling(instant);
long diffFromFloor = instant - floor;
long diffToCeiling = ceiling - instant;
if (diffToCeiling <= diffFromFloor) {
// Closer to the ceiling, or halfway - round ceiling
return ceiling;
} else {
return floor;
}
}
/**
* Round to the nearest whole unit of this field. If the given millisecond
* value is closer to the floor, this function behaves like roundFloor. If
* the millisecond value is closer to the ceiling, this function behaves
* like roundCeiling.
* <p>
* If the millisecond value is exactly halfway between the floor and
* ceiling, the ceiling is chosen over the floor only if it makes this
* field's value even.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to round
* @return rounded milliseconds
*/
public long roundHalfEven(long instant) {
long floor = roundFloor(instant);
long ceiling = roundCeiling(instant);
long diffFromFloor = instant - floor;
long diffToCeiling = ceiling - instant;
if (diffFromFloor < diffToCeiling) {
// Closer to the floor - round floor
return floor;
} else if (diffToCeiling < diffFromFloor) {
// Closer to the ceiling - round ceiling
return ceiling;
} else {
// Round to the instant that makes this field even. If both values
// make this field even (unlikely), favor the ceiling.
if ((get(ceiling) & 1) == 0) {
return ceiling;
}
return floor;
}
}
/**
* Returns the fractional duration milliseconds of this field. In other
* words, calling remainder returns the duration that roundFloor would
* subtract.
* <p>
* For example, on a datetime of 2002-11-02T23:34:56.789, the remainder by
* hour is 34 minutes and 56.789 seconds.
* <p>
* The default implementation computes
* <code>instant - roundFloor(instant). Subclasses are encouraged to
* provide a more efficient implementation.
*
* @param instant the milliseconds from 1970-01-01T00:00:00Z to get the
* remainder
* @return remainder duration, in milliseconds
*/
public long remainder(long instant) {
return instant - roundFloor(instant);
}
/**
* Get a suitable debug string.
*
* @return debug string
*/
public String toString() {
return "DateTimeField[" + getName() + ']';
}
}
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