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Java > Open Source Codes > org > joda > time > field > SkipUndoDateTimeField


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.Chronology;
19 import org.joda.time.DateTimeField;
20
21 /**
22  * Wraps another field such that a certain value is added back into
23  * the sequence of numbers.
24  * <p>
25  * This reverses the effect of SkipDateTimeField. This isn't very
26  * elegant.
27  * <p>
28  * SkipUndoDateTimeField is thread-safe and immutable.
29  *
30  * @author Brian S O'Neill
31  * @author Stephen Colebourne
32  * @since 1.0
33  */
34 public final class SkipUndoDateTimeField extends DelegatedDateTimeField {
35
36     /** Serialization version. */
37     private static final long serialVersionUID = -5875876968979L;
38
39     /** The chronology to wrap. */
40     private final Chronology iChronology;
41     /** The value to skip. */
42     private final int iSkip;
43     /** The calculated minimum value. */
44     private transient int iMinValue;
45
46     /**
47      * Constructor that reinserts zero.
48      *
49      * @param chronology the chronoogy to use
50      * @param field the field to skip zero on
51      */
52     public SkipUndoDateTimeField(Chronology chronology, DateTimeField field) {
53         this(chronology, field, 0);
54     }
55
56     /**
57      * Constructor.
58      *
59      * @param chronology the chronoogy to use
60      * @param field the field to skip zero on
61      * @param skip the value to skip
62      */
63     public SkipUndoDateTimeField(Chronology chronology, DateTimeField field, int skip) {
64         super(field);
65         iChronology = chronology;
66         int min = super.getMinimumValue();
67         if (min < skip) {
68             iMinValue = min + 1;
69         } else if (min == skip + 1) {
70             iMinValue = skip;
71         } else {
72             iMinValue = min;
73         }
74         iSkip = skip;
75     }
76
77     //-----------------------------------------------------------------------
78 public int get(long millis) {
79         int value = super.get(millis);
80         if (value < iSkip) {
81             value++;
82         }
83         return value;
84     }
85
86     public long set(long millis, int value) {
87         FieldUtils.verifyValueBounds(this, value, iMinValue, getMaximumValue());
88         if (value <= iSkip) {
89             value--;
90         }
91         return super.set(millis, value);
92     }
93
94     public int getMinimumValue() {
95         return iMinValue;
96     }
97
98     private Object JavaDoc readResolve() {
99         return getType().getField(iChronology);
100     }
101
102 }
103
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