Java日期操作



1. /**
2. *java日期操作(月末、周末等的日期操作)
3. *
4. *@author
5. *
6. */
7. publicclassDateUtil{
9. /***/
10. /**
11. *取得某天相加(减)後的那一天
12. *
13. *@paramdate
14. *@paramnum
15. *(可正可负)
16. *@return
17. */
18. publicstaticDategetAnotherDate(Datedate,intnum){
19. Calendarc=Calendar.getInstance();
20. c.setTime(date);
21. c.add(Calendar.DAY_OF_YEAR,num);
22. returnc.getTime();
23. }
25. /***/
26. /**
27. *取得某月的的最后一天
28. *
29. *@paramyear
30. *@parammonth
31. *@return
32. */
33. publicstaticDategetLastDayOfMonth(intyear,intmonth){
34. Calendarcal=Calendar.getInstance();
35. cal.set(Calendar.YEAR,year);//年
36. cal.set(Calendar.MONTH,month-1);//月，因为Calendar里的月是从0开始，所以要减1
37. cal.set(Calendar.DATE,1);//日，设为一号
38. cal.add(Calendar.MONTH,1);//月份加一，得到下个月的一号
39. cal.add(Calendar.DATE,-1);//下一个月减一为本月最后一天
40. returncal.getTime();//获得月末是几号
41. }
43. /***/
44. /**
45. *取得某天是一年中的多少周
46. *
47. *@paramdate
48. *@return
49. */
50. publicstaticintgetWeekOfYear(Datedate){
51. Calendarc=newGregorianCalendar();
52. c.setFirstDayOfWeek(Calendar.MONDAY);
53. c.setMinimalDaysInFirstWeek(7);
54. c.setTime(date);
55. returnc.get(Calendar.WEEK_OF_YEAR);
56. }
58. /***/
59. /**
60. *取得某天所在周的第一天
61. *
62. *@paramdate
63. *@return
64. */
65. publicstaticDategetFirstDayOfWeek(Datedate){
66. Calendarc=newGregorianCalendar();
67. c.setFirstDayOfWeek(Calendar.MONDAY);
68. c.setTime(date);
69. c.set(Calendar.DAY_OF_WEEK,c.getFirstDayOfWeek());
70. returnc.getTime();
71. }
73. /***/
74. /**
75. *取得某天所在周的最后一天
76. *
77. *@paramdate
78. *@return
79. */
80. publicstaticDategetLastDayOfWeek(Datedate){
81. Calendarc=newGregorianCalendar();
82. c.setFirstDayOfWeek(Calendar.MONDAY);
83. c.setTime(date);
84. c.set(Calendar.DAY_OF_WEEK,c.getFirstDayOfWeek()+6);
85. returnc.getTime();
86. }
88. /***/
89. /**http://ini.iteye.com/
90. *取得某一年共有多少周
91. *
92. *@paramyear
93. *@return
94. */
95. publicstaticintgetMaxWeekNumOfYear(intyear){
96. Calendarc=newGregorianCalendar();
97. c.set(year,Calendar.DECEMBER,31,23,59,59);
98. returngetWeekOfYear(c.getTime());
99. }
100. /**
101. *http://ini.iteye.com/
102. *获取某一年某一周的日期
103. *@description
104. *@paramyear
105. *@paramweek
106. *@return
107. */
108. publicstaticList<String>getWeekDays(intyear,intweek){
109. List<String>list=newArrayList<String>();
111. Datedate=getFirstDayOfWeek(year,week);
112. SimpleDateFormatd=newSimpleDateFormat("yyyy-MM-dd");
114. for(inti=0;i<7;i++){
115. list.add(d.format(date));
116. System.out.println(d.format(date));
118. date.setDate(date.getDate()+1);
119. }
120. returnlist;
121. }
122. /***/
123. /**
124. *取得某年某周的第一天对于交叉:2008-12-29到2009-01-04属于2008年的最后一周,2009-01-05为2009年第一周的第一天
125. *
126. *@paramyear
127. *@paramweek
128. *@return
129. */
130. publicstaticDategetFirstDayOfWeek(intyear,intweek){
131. CalendarcalFirst=Calendar.getInstance();
132. calFirst.set(year,0,7);
133. DatefirstDate=getFirstDayOfWeek(calFirst.getTime());
135. CalendarfirstDateCal=Calendar.getInstance();
136. firstDateCal.setTime(firstDate);
138. Calendarc=newGregorianCalendar();
139. c.set(Calendar.YEAR,year);
140. c.set(Calendar.MONTH,Calendar.JANUARY);
141. c.set(Calendar.DATE,firstDateCal.get(Calendar.DATE));
143. Calendarcal=(GregorianCalendar)c.clone();
144. cal.add(Calendar.DATE,(week-1)*7);
145. firstDate=getFirstDayOfWeek(cal.getTime());
147. returnfirstDate;
148. }
150. /***/
151. /**
152. *取得某年某周的最后一天对于交叉:2008-12-29到2009-01-04属于2008年的最后一周,2009-01-04为
153. *2008年最后一周的最后一天
154. *
155. *@paramyear
156. *@paramweek
157. *@return
158. */
159. publicstaticDategetLastDayOfWeek(intyear,intweek){
160. CalendarcalLast=Calendar.getInstance();
161. calLast.set(year,0,7);
162. DatefirstDate=getLastDayOfWeek(calLast.getTime());
164. CalendarfirstDateCal=Calendar.getInstance();
165. firstDateCal.setTime(firstDate);
167. Calendarc=newGregorianCalendar();
168. c.set(Calendar.YEAR,year);
169. c.set(Calendar.MONTH,Calendar.JANUARY);
170. c.set(Calendar.DATE,firstDateCal.get(Calendar.DATE));
172. Calendarcal=(GregorianCalendar)c.clone();
173. cal.add(Calendar.DATE,(week-1)*7);
174. DatelastDate=getLastDayOfWeek(cal.getTime());
176. returnlastDate;
177. }
179. /**
180. *获取当前日期的年、月、日
181. */
182. publicvoiddisplay(){
183. Calendarcal=Calendar.getInstance();
184. //年
185. intyear=cal.get(cal.YEAR);
186. //月
187. intmonth=cal.get(cal.MONTH)+1;
188. //日
189. intdate=cal.get(cal.DATE);
190. //星期
191. inttoday=cal.get(cal.DAY_OF_WEEK)-1;
192. }
195. publicstaticvoidmain(Stringargs[]){
197. List<String>listWeekDate=DateUtil.getWeekDays(2010,52);
199. for(Stringweeks:listWeekDate){
200. System.out.println("weeks:"+weeks);
201. }
202. }
203. }