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Java > Open Source Codes > org > joda > time > convert > CalendarConverter


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.convert;
17
18 import java.util.Calendar JavaDoc;
19 import java.util.GregorianCalendar JavaDoc;
20
21 import org.joda.time.Chronology;
22 import org.joda.time.DateTimeZone;
23 import org.joda.time.chrono.BuddhistChronology;
24 import org.joda.time.chrono.GJChronology;
25 import org.joda.time.chrono.GregorianChronology;
26 import org.joda.time.chrono.ISOChronology;
27 import org.joda.time.chrono.JulianChronology;
28
29 /**
30  * CalendarConverter converts a java util Calendar to an instant or partial.
31  * The Calendar is converted to milliseconds and the chronology that best
32  * matches the calendar.
33  *
34  * @author Stephen Colebourne
35  * @since 1.0
36  */
37 final class CalendarConverter extends AbstractConverter
38         implements InstantConverter, PartialConverter {
39
40     /**
41      * Singleton instance.
42      */
43     static final CalendarConverter INSTANCE = new CalendarConverter();
44
45     /**
46      * Restricted constructor.
47      */
48     protected CalendarConverter() {
49         super();
50     }
51
52     //-----------------------------------------------------------------------
53 /**
54      * Gets the chronology.
55      * <p>
56      * If a chronology is specified then it is used.
57      * Otherwise, it is the GJChronology if a GregorianCalendar is used,
58      * BuddhistChronology if a BuddhistCalendar is used or ISOChronology otherwise.
59      * The time zone is extracted from the calendar if possible, default used if not.
60      *
61      * @param object the Calendar to convert, must not be null
62      * @param chrono the chronology to use, null means use Calendar
63      * @return the chronology, never null
64      * @throws NullPointerException if the object is null
65      * @throws ClassCastException if the object is an invalid type
66      */
67     public Chronology getChronology(Object JavaDoc object, Chronology chrono) {
68         if (chrono != null) {
69             return chrono;
70         }
71         Calendar JavaDoc cal = (Calendar JavaDoc) object;
72         DateTimeZone zone = null;
73         try {
74             zone = DateTimeZone.forTimeZone(cal.getTimeZone());
75             
76         } catch (IllegalArgumentException JavaDoc ex) {
77             zone = DateTimeZone.getDefault();
78         }
79         return getChronology(cal, zone);
80     }
81
82     /**
83      * Gets the chronology, which is the GJChronology if a GregorianCalendar is used,
84      * BuddhistChronology if a BuddhistCalendar is used or ISOChronology otherwise.
85      * The time zone specified is used in preference to that on the calendar.
86      *
87      * @param object the Calendar to convert, must not be null
88      * @param zone the specified zone to use, null means default zone
89      * @return the chronology, never null
90      * @throws NullPointerException if the object is null
91      * @throws ClassCastException if the object is an invalid type
92      */
93     public Chronology getChronology(Object JavaDoc object, DateTimeZone zone) {
94         if (object.getClass().getName().endsWith(".BuddhistCalendar")) {
95             return BuddhistChronology.getInstance(zone);
96         } else if (object instanceof GregorianCalendar JavaDoc) {
97             GregorianCalendar JavaDoc gc = (GregorianCalendar JavaDoc) object;
98             long cutover = gc.getGregorianChange().getTime();
99             if (cutover == Long.MIN_VALUE) {
100                 return GregorianChronology.getInstance(zone);
101             } else if (cutover == Long.MAX_VALUE) {
102                 return JulianChronology.getInstance(zone);
103             } else {
104                 return GJChronology.getInstance(zone, cutover, 4);
105             }
106         } else {
107             return ISOChronology.getInstance(zone);
108         }
109     }
110
111     /**
112      * Gets the millis, which is the Calendar millis value.
113      *
114      * @param object the Calendar to convert, must not be null
115      * @param chrono the chronology result from getChronology, non-null
116      * @return the millisecond value
117      * @throws NullPointerException if the object is null
118      * @throws ClassCastException if the object is an invalid type
119      */
120     public long getInstantMillis(Object JavaDoc object, Chronology chrono) {
121         Calendar JavaDoc calendar = (Calendar JavaDoc) object;
122         return calendar.getTime().getTime();
123     }
124
125     //-----------------------------------------------------------------------
126 /**
127      * Returns Calendar.class.
128      *
129      * @return Calendar.class
130      */
131     public Class JavaDoc getSupportedType() {
132         return Calendar JavaDoc.class;
133     }
134
135 }
136
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