本文介紹了Java開發過程中日期相關操作，分享的代碼如下：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
package jse; import java.io.UnsupportedEncodingException;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.Locale; /** * 常用日期操作 * * @author puck * createDate 2015-07-30 22:54:38 */public class TestDate{ public static void main(String[] args) throws ParseException, UnsupportedEncodingException { Calendar cal = Calendar.getInstance();// cal.add(Calendar.DAY_OF_MONTH, -48); System.out.println(dateToString(cal)); } /** * 日期格式化 * @param date * @return */ public static String dateToString(Date date) {// SimpleDateFormat format = new SimpleDateFormat("y年MM月dd日 E HH時mm分ss秒", Locale.CHINA);// SimpleDateFormat format = new SimpleDateFormat("y年M月d日 E H時m分s秒", Locale.CHINA); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA); // example return sdf.format(date); } /** * 日期格式化 * @param date * @return */ public static String dateToString(Calendar cal) { return dateToString(cal.getTime()); } /** * dateString 轉 Calendar * * @param Date * format:2015-06-16 date * @return Calendar * @throws ParseException */ public static Calendar dateStringToCalendar(String dateStr) throws ParseException {// Calendar cal = Calendar.getInstance();// cal.clear();// cal.set(Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(5, 7)) - 1,// Integer.parseInt(date.substring(8, 10)));// return cal; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Date date = sdf.parse(dateStr); Calendar cal = Calendar.getInstance(); cal.setTime(date); return cal; } /** * dateString 轉 Date * * @param Date * format:yyyy-MM-dd HH:mm:ss date * @return Calendar * @throws ParseException */ public static Date dateStringToDate(String date) throws ParseException { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return sdf.parse(date); } /** * Date Convert to Calendar * * @param date * @return */ public static Calendar dateToCalendar(Date date) { Calendar c1 = Calendar.getInstance(); c1.setTime(date); return c1; } /** * Calendar Convert To Date * @param cal * @return */ public static Date CalendarToDate(Calendar cal) { return cal.getTime(); } /** * 計算兩個日期相差年月日 * * @param Date * c1 * @param Date * c2 * @return int[]{year, month, day} */ public int[] calculateDifferDay(Date d1, Date d2) { Calendar c1 = Calendar.getInstance(); c1.setTime(d1); Calendar c2 = Calendar.getInstance(); c1.setTime(d2); return calculateDifferDay(c1, c2); } /** * 計算兩個日期相差年月日 * * @param Calendar * c1 * @param Calendar * c2 * @return int[]{year, month, day} */ public int[] calculateDifferDay(Calendar c1, Calendar c2) { int[] p1 = { c1.get(Calendar.YEAR), c1.get(Calendar.MONTH), c1.get(Calendar.DAY_OF_MONTH) }; int[] p2 = { c2.get(Calendar.YEAR), c2.get(Calendar.MONTH), c2.get(Calendar.DAY_OF_MONTH) }; System.out.println("p1[0]=" + p1[0] + " p1[1]=" + p1[1] + " p1[2]=" + p1[2]); System.out.println("p2[0]=" + p2[0] + " p2[1]=" + p2[1] + " p2[2]=" + p2[2]); int year = p2[0] - p1[0]; int month = (p2[0] * 12) + p2[1] - ((p1[0] * 12) + p1[1]); int day = (int) ((c2.getTimeInMillis() - c1.getTimeInMillis()) / (24 * 60 * 60 * 1000)); return new int[] { year, month, day }; } /** * 獲取日期所在周的第一天 * * @param c * @return */ public static Calendar getLastDayOfWeek(Calendar c) {// SimpleDateFormat format2 = new SimpleDateFormat("y年M月d日 E H時m分s秒", Locale.CHINA);// System.out.println("當前時間:" + format2.format(c.getTime())); c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);// System.out.println("周一時間:" + format2.format(c.getTime())); return c; } /** * 日期加減 * @param c * @param day * @return */ public static Calendar addOrDecreaseDay(Calendar c, int day) { c.add(Calendar.DAY_OF_MONTH, day); return c; } /** * 獲取月最后一天 * @param year * @param month * @return */ public static int getLastDayOfMonth(int year, int month) { Calendar c = Calendar.getInstance(); c.set(year, month - 1, 1); return c.getActualMaximum(Calendar.DAY_OF_MONTH); } /** * 獲取月最后一天 * @param cal * @return */ public static int getLastDayOfMonth(Calendar cal) { return cal.getActualMaximum(Calendar.DAY_OF_MONTH); } } |
