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1   /*
2    *  Copyright 2001-2009 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 org.joda.time.Chronology;
19  import org.joda.time.DateTimeUtils;
20  import org.joda.time.DateTimeZone;
21  import org.joda.time.ReadableInstant;
22  import org.joda.time.chrono.ISOChronology;
23  
24  /**
25   * ReadableInstantConverter extracts milliseconds and chronology from a ReadableInstant.
26   *
27   * @author Stephen Colebourne
28   * @since 1.0
29   */
30  class ReadableInstantConverter extends AbstractConverter
31          implements InstantConverter, PartialConverter {
32  
33      /**
34       * Singleton instance.
35       */
36      static final ReadableInstantConverter INSTANCE = new ReadableInstantConverter();
37  
38      /**
39       * Restricted constructor.
40       */
41      protected ReadableInstantConverter() {
42          super();
43      }
44  
45      //-----------------------------------------------------------------------
46      /**
47       * Gets the chronology, which is taken from the ReadableInstant.
48       * If the chronology on the instant is null, the ISOChronology in the
49       * specified time zone is used.
50       * If the chronology on the instant is not in the specified zone, it is
51       * adapted.
52       * 
53       * @param object  the ReadableInstant to convert, must not be null
54       * @param zone  the specified zone to use, null means default zone
55       * @return the chronology, never null
56       */
57      public Chronology getChronology(Object object, DateTimeZone zone) {
58          Chronology chrono = ((ReadableInstant) object).getChronology();
59          if (chrono == null) {
60              return ISOChronology.getInstance(zone);
61          }
62          DateTimeZone chronoZone = chrono.getZone();
63          if (chronoZone != zone) {
64              chrono = chrono.withZone(zone);
65              if (chrono == null) {
66                  return ISOChronology.getInstance(zone);
67              }
68          }
69          return chrono;
70      }
71  
72      /**
73       * Gets the chronology, which is taken from the ReadableInstant.
74       * <p>
75       * If the passed in chronology is non-null, it is used.
76       * Otherwise the chronology from the instant is used.
77       * 
78       * @param object  the ReadableInstant to convert, must not be null
79       * @param chrono  the chronology to use, null means use that from object
80       * @return the chronology, never null
81       */
82      public Chronology getChronology(Object object, Chronology chrono) {
83          if (chrono == null) {
84              chrono = ((ReadableInstant) object).getChronology();
85              chrono = DateTimeUtils.getChronology(chrono);
86          }
87          return chrono;
88      }
89  
90      /**
91       * Extracts the millis from an object of this convertor's type.
92       * 
93       * @param object  the ReadableInstant to convert, must not be null
94       * @param chrono  the non-null result of getChronology
95       * @return the millisecond value
96       * @throws NullPointerException if the object is null
97       * @throws ClassCastException if the object is an invalid type
98       */
99      public long getInstantMillis(Object object, Chronology chrono) {
100         return ((ReadableInstant) object).getMillis();
101     }
102 
103     //-----------------------------------------------------------------------
104     /**
105      * Returns ReadableInstant.class.
106      * 
107      * @return ReadableInstant.class
108      */
109     public Class<?> getSupportedType() {
110         return ReadableInstant.class;
111     }
112 
113 }