joda-time/joda-time/2.10 : org/joda/time/field/BaseDateTimeField.java

BaseDateTimeField
http://www.joda.org/joda-time/: Date and time library to replace JDK date handling (Joda.org)
Apache 2
/*
 *  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. 

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.

BaseDateTimeField is thread-safe and immutable, and its subclasses must
be as well.
Author: Brian S O'Neill
See Also: DecoratedDateTimeField
Since: 1.0/**
 * 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. /** The field type. */
    private final DateTimeFieldType iType;

    Constructor.
/**
     * 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();
    }

    Returns: true always/**
     * @return true always
     */
    public final boolean isSupported() {
        return true;
    }

    // Main access API
    //------------------------------------------------------------------------
    Get the value of this field from the milliseconds.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
Returns: the value of the field, in the units of the field/**
     * 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.

The default implementation returns getAsText(get(instant), locale).
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
locale – the locale to use for selecting a text symbol, null means default
Returns: the text value of the field/**
     * 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.
 The default implementation calls getAsText(long, Locale). 
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
Returns: the text value of the field/**
     * 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.

The default implementation returns getAsText(fieldValue, locale).
Params: partial –  the partial instant to query
fieldValue –  the field value of this field, provided for performance
locale –  the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.
 The default implementation calls ReadablePartial.get(DateTimeFieldType) and getAsText(ReadablePartial, int, Locale). 
Params: partial –  the partial instant to query
locale –  the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.

The default implementation returns Integer.toString(get(instant)).

Note: subclasses that override this method should also override
getMaximumTextLength.
Params: fieldValue –  the numeric value to convert to text
locale – the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.

The default implementation returns getAsShortText(get(instant), locale).
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
locale – the locale to use for selecting a text symbol, null means default
Returns: the text value of the field/**
     * 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.
 The default implementation calls getAsShortText(long, Locale). 
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
Returns: the text value of the field/**
     * 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.

The default implementation returns getAsShortText(fieldValue, locale).
Params: partial –  the partial instant to query
fieldValue –  the field value of this field, provided for performance
locale –  the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.
 The default implementation calls ReadablePartial.get(DateTimeFieldType) and getAsText(ReadablePartial, int, Locale). 
Params: partial –  the partial instant to query
locale –  the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.

The default implementation returns getAsText(fieldValue, locale).

Note: subclasses that override this method should also override
getMaximumShortTextLength.
Params: fieldValue –  the numeric value to convert to text
locale – the locale to use for selecting a text symbol, null for default
Returns: the text value of the field/**
     * 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.

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.

For example, in the ISO chronology:

2000-08-20 add six months is 2001-02-20

2000-08-20 add twenty months is 2002-04-20

2000-08-20 add minus nine months is 1999-11-20

2001-01-31 add one month  is 2001-02-28

2001-01-31 add two months is 2001-03-31

Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to add to
value –  the value to add, in the units of the field
Returns: the updated milliseconds/**
     * 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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to add to
value –  the long value to add, in the units of the field
Throws: IllegalArgumentException – if value is too large
See Also: add(long, int)
Returns: the updated milliseconds/**
     * 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.

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.

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.

For example, in the ISO chronology:

2000-08-20 add six months is 2000-02-20

2000-08-20 add twenty months is 2000-04-20

2000-08-20 add minus nine months is 2000-11-20

2001-01-31 add one month  is 2001-02-28

2001-01-31 add two months is 2001-03-31

Params: instant –  the partial instant
fieldIndex –  the index of this field in the partial
values –  the values of the partial instant which should be updated
valueToAdd –  the value to add, in the units of the field
Throws: IllegalArgumentException – if the value is invalid or the maximum instant is reached
Returns: the passed in values/**
     * 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.

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.

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 this 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.

For example, in the ISO chronology:

10:20:30 add 20 minutes is 10:40:30

10:20:30 add 45 minutes is 11:05:30

10:20:30 add 16 hours is 02:20:30

Params: instant –  the partial instant
fieldIndex –  the index of this field in the partial
values –  the values of the partial instant which should be updated
valueToAdd –  the value to add, in the units of the field
Throws: IllegalArgumentException – if the value is invalid or the maximum instant is reached
Returns: the passed in values/**
     * 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 this 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.

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.

For example, in the ISO chronology:

2000-08-20 addWrapField six months is 2000-02-20

2000-08-20 addWrapField twenty months is 2000-04-20

2000-08-20 addWrapField minus nine months is 2000-11-20

2001-01-31 addWrapField one month  is 2001-02-28

2001-01-31 addWrapField two months is 2001-03-31


The default implementation internally calls set. Subclasses are
encouraged to provide a more efficient implementation.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to add to
value –  the value to add, in the units of the field
Returns: the updated milliseconds/**
     * 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.

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.

For example, in the ISO chronology:

2000-08-20 addWrapField six months is 2000-02-20

2000-08-20 addWrapField twenty months is 2000-04-20

2000-08-20 addWrapField minus nine months is 2000-11-20

2001-01-31 addWrapField one month  is 2001-02-28

2001-01-31 addWrapField two months is 2001-03-31


The default implementation internally calls set. Subclasses are
encouraged to provide a more efficient implementation.
Params: instant –  the partial instant
fieldIndex –  the index of this field in the instant
values –  the values of the partial instant which should be updated
valueToAdd –  the value to add, in the units of the field
Throws: IllegalArgumentException – if the value is invalid
Returns: the passed in values/**
     * 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:
long instant = ...
int v = ...
int age = getDifference(add(instant, v), instant);

The value 'age' is the same as the value 'v'.
Params: minuendInstant – the milliseconds from 1970-01-01T00:00:00Z to
subtract from
subtrahendInstant – the milliseconds from 1970-01-01T00:00:00Z to
subtract off the minuend
Returns: the difference in the units of this field/**
     * 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:
long instant = ...
long v = ...
long age = getDifferenceAsLong(add(instant, v), instant);

The value 'age' is the same as the value 'v'.
Params: minuendInstant – the milliseconds from 1970-01-01T00:00:00Z to
subtract from
subtrahendInstant – the milliseconds from 1970-01-01T00:00:00Z to
subtract off the minuend
Returns: the difference in the units of this field/**
     * 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.

The value of this field will be set.
If the value is invalid, an exception if thrown.

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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to set in
value –  the value to set, in the units of the field
Throws: IllegalArgumentException – if the value is invalid
Returns: the updated milliseconds/**
     * 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.

The value of this field (specified by the index) will be set.
If the value is invalid, an exception if thrown.

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.
Params: partial –  the partial instant
fieldIndex –  the index of this field in the instant
values –  the values to update
newValue –  the value to set, in the units of the field
Throws: IllegalArgumentException – if the value is invalid
Returns: the updated values/**
     * 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.

This implementation uses convertText(String, Locale) and set(long, int). 

Note: subclasses that override this method should also override
getAsText.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to set in
text –  the text value to set
locale – the locale to use for selecting a text symbol, null for default
Throws: IllegalArgumentException – if the text value is invalid
Returns: the updated milliseconds/**
     * 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)</code> 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.
 This implementation uses set(long, String, Locale). 

Note: subclasses that override this method should also override getAsText.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to set in
text –  the text value to set
Throws: IllegalArgumentException – if the text value is invalid
Returns: the updated milliseconds/**
     * 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.

This implementation uses convertText(String, Locale) and set(ReadablePartial, int, int[], int). 
Params: instant –  the partial instant
fieldIndex –  the index of this field in the instant
values –  the values of the partial instant which should be updated
text –  the text value to set
locale – the locale to use for selecting a text symbol, null for default
Throws: IllegalArgumentException – if the text value is invalid
Returns: the passed in 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)</code> 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.
Params: text –  the text to convert
locale –  the locale to convert using
Throws: IllegalArgumentException – if the text is invalid
Returns: the value extracted from the text/**
     * 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.
Returns: the duration of this field, or UnsupportedDurationField if field
has no duration/**
     * 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.
Returns: the range duration of this field, or null if field has no range/**
     * 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.

For example, a leap year would return true, a non leap year would return
false.

This implementation returns false.
Returns: true if the field is 'leap'/**
     * 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.

For example, a leap year would return one, a non leap year would return
zero.

This implementation returns zero.
/**
     * 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.

This implementation returns null.
/**
     * 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.
Returns: the minimum valid value for this field, in the units of the
field/**
     * 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.
 This implementation returns the same as getMinimumValue(). 
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
Returns: the minimum value for this field, in the units of the field/**
     * 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.
 This implementation returns the same as getMinimumValue(). 
Params: instant –  the partial instant to query
Returns: the minimum value for this field, in the units of the field/**
     * 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.
 This implementation returns the same as getMinimumValue(ReadablePartial). 
Params: instant –  the partial instant to query
values –  the values to use
Returns: the minimum value for this field, in the units of the field/**
     * 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.
Returns: the maximum valid value for this field, in the units of the
field/**
     * 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.
 This implementation returns the same as getMaximumValue(). 
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to query
Returns: the maximum value for this field, in the units of the field/**
     * 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.
 This implementation returns the same as getMaximumValue(). 
Params: instant –  the partial instant to query
Returns: the maximum value for this field, in the units of the field/**
     * 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.
 This implementation returns the same as getMaximumValue(ReadablePartial). 
Params: instant –  the partial instant to query
values –  the values to use
Returns: the maximum value for this field, in the units of the field/**
     * 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().
Params: locale –  the locale to use for selecting a text symbol
Returns: the maximum text length/**
     * 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().
Params: locale –  the locale to use for selecting a text symbol
Returns: the maximum short text 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.

For example, a datetime of 2002-11-02T23:34:56.789, rounded to the
lowest whole hour is 2002-11-02T23:00:00.000.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to round
Returns: rounded milliseconds/**
     * 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.

For example, a datetime of 2002-11-02T23:34:56.789, rounded to the
highest whole hour is 2002-11-03T00:00:00.000.

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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to round
Returns: rounded milliseconds/**
     * 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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to round
Returns: rounded milliseconds/**
     * 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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to round
Returns: rounded milliseconds/**
     * 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.

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.
Params: instant –  the milliseconds from 1970-01-01T00:00:00Z to round
Returns: rounded milliseconds/**
     * 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.

For example, on a datetime of 2002-11-02T23:34:56.789, the remainder by
hour is 34 minutes and 56.789 seconds.

The default implementation computes
instant - roundFloor(instant). Subclasses are encouraged to
provide a more efficient implementation.
Params: instant – the milliseconds from 1970-01-01T00:00:00Z to get the
remainder
Returns: remainder duration, in milliseconds/**
     * 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)</code>. 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.
Returns: debug string/**
     * Get a suitable debug string.
     * 
     * @return debug string
     */
    public String toString() {
        return "DateTimeField[" + getName() + ']';
    }

}
Author:	Brian S O'Neill
See Also:	DecoratedDateTimeField
Since:	1.0
Params:	instant – the milliseconds from 1970-01-01T00:00:00Z to query
Returns:	the value of the field, in the units of the field
Params:	partial – the partial instant to query fieldValue – the field value of this field, provided for performance locale – the locale to use for selecting a text symbol, null for default
Returns:	the text value of the field
Params:	partial – the partial instant to query locale – the locale to use for selecting a text symbol, null for default
Returns:	the text value of the field
Params:	fieldValue – the numeric value to convert to text locale – the locale to use for selecting a text symbol, null for default
Returns:	the text value of the field
Params:	instant – the milliseconds from 1970-01-01T00:00:00Z to add to value – the long value to add, in the units of the field
Throws:	IllegalArgumentException – if value is too large
See Also:	add(long, int)
Returns:	the updated milliseconds
Params:	instant – the partial instant fieldIndex – the index of this field in the partial values – the values of the partial instant which should be updated valueToAdd – the value to add, in the units of the field
Throws:	IllegalArgumentException – if the value is invalid or the maximum instant is reached
Returns:	the passed in values
Params:	minuendInstant – the milliseconds from 1970-01-01T00:00:00Z to subtract from subtrahendInstant – the milliseconds from 1970-01-01T00:00:00Z to subtract off the minuend
Returns:	the difference in the units of this field
Params:	partial – the partial instant fieldIndex – the index of this field in the instant values – the values to update newValue – the value to set, in the units of the field
Throws:	IllegalArgumentException – if the value is invalid
Returns:	the updated values
Params:	text – the text to convert locale – the locale to convert using
Throws:	IllegalArgumentException – if the text is invalid
Returns:	the value extracted from the text
Params:	instant – the partial instant to query
Returns:	the minimum value for this field, in the units of the field
Params:	instant – the partial instant to query values – the values to use
Returns:	the minimum value for this field, in the units of the field
Params:	locale – the locale to use for selecting a text symbol
Returns:	the maximum text length
/

joda-time/ joda-time/ 2.10/ org/joda/time/field/BaseDateTimeField.java
