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, which has a precise unit duration field.
23 * <p>
24 * PreciseDurationDateTimeField is thread-safe and immutable, and its
25 * subclasses must be as well.
26 *
27 * @author Brian S O'Neill
28 * @since 1.0
29 */
30 public abstract class PreciseDurationDateTimeField extends BaseDateTimeField {
31
32 private static final long serialVersionUID = 5004523158306266035L;
33
34 /** The fractional unit in millis */
35 final long iUnitMillis;
36
37 private final DurationField iUnitField;
38
39 /**
40 * Constructor.
41 *
42 * @param type the field type
43 * @param unit precise unit duration, like "days()".
44 * @throws IllegalArgumentException if duration field is imprecise
45 * @throws IllegalArgumentException if unit milliseconds is less than one
46 */
47 public PreciseDurationDateTimeField(DateTimeFieldType type, DurationField unit) {
48 super(type);
49
50 if (!unit.isPrecise()) {
51 throw new IllegalArgumentException("Unit duration field must be precise");
52 }
53
54 iUnitMillis = unit.getUnitMillis();
55 if (iUnitMillis < 1) {
56 throw new IllegalArgumentException("The unit milliseconds must be at least 1");
57 }
58
59 iUnitField = unit;
60 }
61
62 /**
63 * Returns false by default.
64 */
65 public boolean isLenient() {
66 return false;
67 }
68
69 /**
70 * Set the specified amount of units to the specified time instant.
71 *
72 * @param instant the milliseconds from 1970-01-01T00:00:00Z to set in
73 * @param value value of units to set.
74 * @return the updated time instant.
75 * @throws IllegalArgumentException if value is too large or too small.
76 */
77 public long set(long instant, int value) {
78 FieldUtils.verifyValueBounds(this, value, getMinimumValue(),
79 getMaximumValueForSet(instant, value));
80 return instant + (value - get(instant)) * iUnitMillis;
81 }
82
83 /**
84 * This method assumes that this field is properly rounded on
85 * 1970-01-01T00:00:00. If the rounding alignment differs, override this
86 * method as follows:
87 * <pre>
88 * return super.roundFloor(instant + ALIGNMENT_MILLIS) - ALIGNMENT_MILLIS;
89 * </pre>
90 */
91 public long roundFloor(long instant) {
92 if (instant >= 0) {
93 return instant - instant % iUnitMillis;
94 } else {
95 instant += 1;
96 return instant - instant % iUnitMillis - iUnitMillis;
97 }
98 }
99
100 /**
101 * This method assumes that this field is properly rounded on
102 * 1970-01-01T00:00:00. If the rounding alignment differs, override this
103 * method as follows:
104 * <pre>
105 * return super.roundCeiling(instant + ALIGNMENT_MILLIS) - ALIGNMENT_MILLIS;
106 * </pre>
107 */
108 public long roundCeiling(long instant) {
109 if (instant > 0) {
110 instant -= 1;
111 return instant - instant % iUnitMillis + iUnitMillis;
112 } else {
113 return instant - instant % iUnitMillis;
114 }
115 }
116
117 /**
118 * This method assumes that this field is properly rounded on
119 * 1970-01-01T00:00:00. If the rounding alignment differs, override this
120 * method as follows:
121 * <pre>
122 * return super.remainder(instant + ALIGNMENT_MILLIS);
123 * </pre>
124 */
125 public long remainder(long instant) {
126 if (instant >= 0) {
127 return instant % iUnitMillis;
128 } else {
129 return (instant + 1) % iUnitMillis + iUnitMillis - 1;
130 }
131 }
132
133 /**
134 * Returns the duration per unit value of this field. For example, if this
135 * field represents "minute of hour", then the duration field is minutes.
136 *
137 * @return the duration of this field, or UnsupportedDurationField if field
138 * has no duration
139 */
140 public DurationField getDurationField() {
141 return iUnitField;
142 }
143
144 /**
145 * Get the minimum value for the field.
146 *
147 * @return the minimum value
148 */
149 public int getMinimumValue() {
150 return 0;
151 }
152
153 public final long getUnitMillis() {
154 return iUnitMillis;
155 }
156
157 /**
158 * Called by the set method to get the maximum allowed value. By default,
159 * returns getMaximumValue(instant). Override to provide a faster
160 * implementation.
161 */
162 protected int getMaximumValueForSet(long instant, int value) {
163 return getMaximumValue(instant);
164 }
165
166 }