| 1 | /* |
| 2 | * Copyright 2001-2005 Stephen Colebourne |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.joda.time.field; |
| 17 | |
| 18 | import org.joda.time.DateTimeFieldType; |
| 19 | import org.joda.time.DurationField; |
| 20 | |
| 21 | /** |
| 22 | * Precise datetime field, composed of two precise duration fields. |
| 23 | * <p> |
| 24 | * This DateTimeField is useful for defining DateTimeFields that are composed |
| 25 | * of precise durations, like time of day fields. If either duration field is |
| 26 | * imprecise, then an {@link ImpreciseDateTimeField} may be used instead. |
| 27 | * <p> |
| 28 | * PreciseDateTimeField is thread-safe and immutable. |
| 29 | * |
| 30 | * @author Brian S O'Neill |
| 31 | * @author Stephen Colebourne |
| 32 | * @since 1.0 |
| 33 | * @see ImpreciseDateTimeField |
| 34 | */ |
| 35 | public class PreciseDateTimeField extends PreciseDurationDateTimeField { |
| 36 | |
| 37 | private static final long serialVersionUID = -5586801265774496376L; |
| 38 | |
| 39 | /** The maximum range in the correct units */ |
| 40 | private final int iRange; |
| 41 | |
| 42 | private final DurationField iRangeField; |
| 43 | |
| 44 | /** |
| 45 | * Constructor. |
| 46 | * |
| 47 | * @param type the field type this field uses |
| 48 | * @param unit precise unit duration, like "seconds()". |
| 49 | * @param range precise range duration, preferably a multiple of the unit, |
| 50 | * like "minutes()". |
| 51 | * @throws IllegalArgumentException if either duration field is imprecise |
| 52 | * @throws IllegalArgumentException if unit milliseconds is less than one |
| 53 | * or effective value range is less than two. |
| 54 | */ |
| 55 | public PreciseDateTimeField(DateTimeFieldType type, |
| 56 | DurationField unit, DurationField range) { |
| 57 | super(type, unit); |
| 58 | |
| 59 | if (!range.isPrecise()) { |
| 60 | throw new IllegalArgumentException("Range duration field must be precise"); |
| 61 | } |
| 62 | |
| 63 | long rangeMillis = range.getUnitMillis(); |
| 64 | iRange = (int)(rangeMillis / getUnitMillis()); |
| 65 | if (iRange < 2) { |
| 66 | throw new IllegalArgumentException("The effective range must be at least 2"); |
| 67 | } |
| 68 | |
| 69 | iRangeField = range; |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Get the amount of fractional units from the specified time instant. |
| 74 | * |
| 75 | * @param instant the milliseconds from 1970-01-01T00:00:00Z to query |
| 76 | * @return the amount of fractional units extracted from the input. |
| 77 | */ |
| 78 | public int get(long instant) { |
| 79 | if (instant >= 0) { |
| 80 | return (int) ((instant / getUnitMillis()) % iRange); |
| 81 | } else { |
| 82 | return iRange - 1 + (int) (((instant + 1) / getUnitMillis()) % iRange); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Add to the component of the specified time instant, wrapping around |
| 88 | * within that component if necessary. |
| 89 | * |
| 90 | * @param instant the milliseconds from 1970-01-01T00:00:00Z to add to |
| 91 | * @param amount the amount of units to add (can be negative). |
| 92 | * @return the updated time instant. |
| 93 | */ |
| 94 | public long addWrapField(long instant, int amount) { |
| 95 | int thisValue = get(instant); |
| 96 | int wrappedValue = FieldUtils.getWrappedValue |
| 97 | (thisValue, amount, getMinimumValue(), getMaximumValue()); |
| 98 | // copy code from set() to avoid repeat call to get() |
| 99 | return instant + (wrappedValue - thisValue) * getUnitMillis(); |
| 100 | } |
| 101 | |
| 102 | /** |
| 103 | * Set the specified amount of units to the specified time instant. |
| 104 | * |
| 105 | * @param instant the milliseconds from 1970-01-01T00:00:00Z to set in |
| 106 | * @param value value of units to set. |
| 107 | * @return the updated time instant. |
| 108 | * @throws IllegalArgumentException if value is too large or too small. |
| 109 | */ |
| 110 | public long set(long instant, int value) { |
| 111 | FieldUtils.verifyValueBounds(this, value, getMinimumValue(), getMaximumValue()); |
| 112 | return instant + (value - get(instant)) * iUnitMillis; |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * Returns the range duration of this field. For example, if this field |
| 117 | * represents "minute of hour", then the range duration field is an hours. |
| 118 | * |
| 119 | * @return the range duration of this field, or null if field has no range |
| 120 | */ |
| 121 | public DurationField getRangeDurationField() { |
| 122 | return iRangeField; |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Get the maximum value for the field. |
| 127 | * |
| 128 | * @return the maximum value |
| 129 | */ |
| 130 | public int getMaximumValue() { |
| 131 | return iRange - 1; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Returns the range of the field in the field's units. |
| 136 | * <p> |
| 137 | * For example, 60 for seconds per minute. The field is allowed values |
| 138 | * from 0 to range - 1. |
| 139 | * |
| 140 | * @return unit range |
| 141 | */ |
| 142 | public int getRange() { |
| 143 | return iRange; |
| 144 | } |
| 145 | |
| 146 | } |