CalendarUtils


1   /*
2    * (c) Rob Gordon 2005
3    */
4   package org.oddjob.schedules;
5   
6   import java.util.Calendar  ;
7   import java.util.Date  ;
8   import java.util.TimeZone  ;
9   
10  public class CalendarUtils {
11  
12      /**
13       * Set the calendar to the end of day.
14       * 
15       * @param calendar The calendar that will be set.
16       */
17      public static void setEndOfDay(Calendar   calendar) {
18          calendar.set(Calendar.HOUR_OF_DAY, 23);
19          calendar.set(Calendar.MINUTE, 59);
20          calendar.set(Calendar.SECOND, 59);
21          calendar.set(Calendar.MILLISECOND, 999);
22      }
23      
24      /**
25       * Set the calendar to the end of the month.
26       * 
27       * @param calendar The calendar that will be set.
28       */
29      public static void setEndOfMonth(Calendar   calendar) {
30          calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) + 1);
31          calendar.set(Calendar.DAY_OF_MONTH, 0);
32          calendar.set(Calendar.HOUR_OF_DAY, 23);
33          calendar.set(Calendar.MINUTE, 59);
34          calendar.set(Calendar.SECOND, 59);
35          calendar.set(Calendar.MILLISECOND, 999);
36      }
37      
38      /**
39       * Calculate the date at the start of the month for the given date.
40       * 
41       * @param inDate The given date.
42       * @return The date at the start of the month.
43       */
44      public static Calendar   startOfMonth(Date   inDate, TimeZone   timeZone) {
45          Calendar   c1 = Calendar.getInstance(timeZone);
46          c1.setTime(inDate);
47          
48          Calendar   c2 = Calendar.getInstance(timeZone);
49          c2.clear();
50          c2.set(c1.get(Calendar.YEAR), c1.get(Calendar.MONTH), 1);
51          return c2;
52      }
53  
54      /**
55       * Calculate the date at the end of the month for the given date.
56       * 
57       * @param inDate The given date.
58       * @return The calendar at the end of the month.
59       */
60      public static Calendar   endOfMonth(Date   inDate, TimeZone   timeZone) {
61          Calendar   c1 = Calendar.getInstance(timeZone);
62          c1.setTime(inDate);
63          
64          // get the date at the beginning of next month
65          Calendar   c2 = Calendar.getInstance(timeZone);
66          c2.clear();
67          c2.set(c1.get(Calendar.YEAR), c1.get(Calendar.MONTH) + 1, 1);
68          // and take off a millisecond.
69          c2.add(Calendar.MILLISECOND, -1);
70          return c2;
71      }
72      
73      /**
74       * Utility function to get a calendar which 
75       * represents the day of the month in which the reference date is.
76       * 
77       * @param referenceDate The date to take month from.
78       * @param day The day.
79       * @return The Calendar.
80       */
81      public static Calendar   dayOfMonth(Date   referenceDate, int day, TimeZone   timeZone) {
82          Calendar   c1 = Calendar.getInstance(timeZone);
83          c1.setTime(referenceDate);
84          
85          int month = day > 0 ? c1.get(Calendar.MONTH) : c1.get(Calendar.MONTH) + 1;
86          
87          Calendar   c2 = Calendar.getInstance(timeZone);
88          c2.clear();
89          c2.set(c1.get(Calendar.YEAR), month, day);
90          return c2;
91      }
92          
93      /**
94       * Calculate the start of the week for the given date.
95       * 
96       * @param inDate The given date.
97       * 
98       * @return The date at the start of the month.
99       */
100     public static Calendar   startOfWeek(Date   inDate, TimeZone   timeZone) {
101         Calendar   c1 = Calendar.getInstance(timeZone);
102         c1.setTime(inDate);
103         
104         Calendar   c2 = Calendar.getInstance(timeZone);
105         c2.clear();
106         c2.set(c1.get(Calendar.YEAR), c1.get(Calendar.MONTH), 
107                 c1.get(Calendar.DAY_OF_MONTH) - (c1.get(Calendar.DAY_OF_WEEK) - 1));
108         return c2;      
109     }
110 
111     /**
112      * Calculate the start of the week for the given date.
113      * 
114      * @param inDate The given date.
115      * 
116      * @return The date at the start of the month.
117      */
118     public static Calendar   endOfWeek(Date   inDate, TimeZone   timeZone) {
119         Calendar   c1 = Calendar.getInstance(timeZone);
120         c1.setTime(inDate);
121         
122         Calendar   c2 = Calendar.getInstance(timeZone);
123         c2.clear();
124         c2.set(c1.get(Calendar.YEAR), c1.get(Calendar.MONTH), 
125                 c1.get(Calendar.DAY_OF_MONTH) + (8 - c1.get(Calendar.DAY_OF_WEEK)));
126         c2.add(Calendar.MILLISECOND, -1);
127         return c2;
128     }
129     
130     /**
131      * Utility function to get a calendar which 
132      * represents the day of the week from the reference date.
133 
134      * @param referenceDate The date to take week from.
135      * @param day The day.
136      * @return The Calendar.
137      */
138     public static Calendar   dayOfWeek(Date   referenceDate, int day, TimeZone   timeZone) {
139         
140         Calendar   c1 = Calendar.getInstance(timeZone);
141         c1.setTime(referenceDate);
142         
143         Calendar   c2 = Calendar.getInstance(timeZone);
144         c2.clear();
145         c2.set(c1.get(Calendar.YEAR), c1.get(Calendar.MONTH), 
146                 c1.get(Calendar.DAY_OF_MONTH));
147         c2.add(Calendar.DATE, day - c1.get(Calendar.DAY_OF_WEEK));
148         return c2;
149     }
150     
151     /**
152      * Calculate the date at the start of the year for the given date.
153      * 
154      * @param referenceDate The given date.
155      * @return The calendar at the start of the year.
156      */
157     public static Calendar   startOfYear(Date   referenceDate, TimeZone   timeZone) {
158         Calendar   c1 = Calendar.getInstance(timeZone);
159         c1.setTime(referenceDate);
160         
161         Calendar   c2 = Calendar.getInstance(timeZone);
162         c2.clear();
163         c2.set(c1.get(Calendar.YEAR), 0, 1);
164         return c2;      
165     }
166 
167     /**
168      * Calcuate the date at the end of the year from the
169      * given date.
170      * 
171      * @param referenceDate The given date.
172      * @return The calendar at the end of the year.
173      */
174     public static Calendar   endOfYear(Date   referenceDate, TimeZone   timeZone) {
175         Calendar   c1 = Calendar.getInstance(timeZone);
176         c1.setTime(referenceDate);
177         
178         Calendar   c2 = Calendar.getInstance();
179         c2.clear();
180         c2.set(c1.get(Calendar.YEAR) + 1, 0, 1);
181         c2.setTimeZone(timeZone);
182         // and take off a millisecond.
183         c2.add(Calendar.MILLISECOND, -1);
184         return c2;
185     }
186 
187 
188     /**
189      * Calendar for the day of year.
190      * 
191      * @param referenceDate The date to take year from.
192      * @param dayOfYear The day of the year.
193      * @return The calendar.
194      */
195     public static Calendar   dayOfYear(Date   referenceDate, int dayOfYear, TimeZone   timeZone) {
196         Calendar   c1 = Calendar.getInstance();
197         c1.setTimeZone(timeZone);
198         c1.setTime(referenceDate);
199         
200         Calendar   c2 = Calendar.getInstance(timeZone);
201         c2.clear();
202         c2.set(Calendar.YEAR, c1.get(Calendar.YEAR));
203         c2.set(Calendar.DAY_OF_YEAR, dayOfYear);
204         return c2;
205     }
206 
207     /**
208      * Utility function to get the start of the month as a Calendar.
209      * 
210      * @param referenceDate The whole date.
211      * @param month The month to calculate the start of.
212      * @return The start of the month.
213      */
214     public static Calendar   monthOfYear(Date   referenceDate, int month, TimeZone   timeZone) {      
215         Calendar   c1 = Calendar.getInstance(timeZone);
216         c1.setTime(referenceDate);
217         
218         Calendar   c2 = Calendar.getInstance(timeZone);
219         c2.clear();
220         c2.set(c1.get(Calendar.YEAR), month, 1);
221         return c2;
222     }
223 
224 }
225
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