1. Calendar calendar = new GregorianCalendar();  
2.     // 1. 當前登陸日期的周一至周五的日期 比如 現(xiàn)在是2012-06-11 周一是2012-06-11 周五就是 2012-06-15。  
3.         calendar.set(Calendar.DAY_OF_WEEK, 2);  
4.         System.out.println("登錄日期的周一：" + print(calendar.getTime()));  
5.         // 2.星期五,，第六天s  
6.         calendar.set(Calendar.DAY_OF_WEEK, 6);  
7.         System.out.println("登錄日期的周五：" + print(calendar.getTime()));  
8.         // 3.當前月的第一天  
9.         calendar.set(Calendar.DAY_OF_MONTH, 1);  
10.         System.out.println("當前月的第一天：" + print(calendar.getTime()));  
11.         // 4.當前月的最后一天  
12.         calendar.add(Calendar.MONTH, 1);  
13.         calendar.set(Calendar.DAY_OF_MONTH, 0);  
14.         System.out.println("當前月的最后一天：" + print(calendar.getTime()));  
15.   
16.         // 季度初  
17.         calendar.setTime(new Date());  
18.         int month = getQuarterInMonth(calendar.get(Calendar.MONTH), true);  
19.         calendar.set(Calendar.MONTH, month);  
20.         calendar.set(Calendar.DAY_OF_MONTH, 1);  
21.         System.out.println("當季度的第一天：" + print(calendar.getTime()));  
22.         // 季度末  
23.         calendar.setTime(new Date());  
24.         month = getQuarterInMonth(calendar.get(Calendar.MONTH), false);  
25.         calendar.set(Calendar.MONTH, month + 1);  
26.         calendar.set(Calendar.DAY_OF_MONTH, 0);  
27.         System.out.println("當前時間的季度末：" + print(calendar.getTime()));  
28.     }  
29.   
30.     private static String print(Date d) {  
31.         DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
32.         return df.format(d);  
33.     }  
34.   
35.     // 返回第幾個月份,，不是幾月  
36.     // 季度一年四季， 第一季度：2月-4月,， 第二季度：5月-7月,， 第三季度：8月-10月， 第四季度：11月-1月  
37.     private static int getQuarterInMonth(int month, boolean isQuarterStart) {  
38.         int months[] = { 1, 4, 7, 10 };  
39.         if (!isQuarterStart) {  
40.             months = new int[] { 3, 6, 9, 12 };  
41.         }  
42.         if (month >= 2 && month <= 4)  
43.             return months[0];  
44.         else if (month >= 5 && month <= 7)  
45.             return months[1];  
46.         else if (month >= 8 && month <= 10)  
47.             return months[2];  
48.         else  
49.             return months[3];  
50.     } 
    

二,、

1. /** 
2.      * 獲取指定日期所在周的周一 
3.      * @Methods Name getMonday 
4.      * @return Date 
5.      */  
6.     public Date getMonday(Date date){  
7.         Calendar cDay = Calendar.getInstance();     
8.         cDay.setTime(date);     
9.         cDay.set(Calendar.DAY_OF_WEEK, 2);//老外將周日定位第一天,，周一取第二天  
10.         return cDay.getTime();     
11.     }  
12.     /** 
13.      * 獲取指定日期所在周日 
14.      * @Methods Name getSunday 
15.      * @return Date 
16.      */  
17.     public Date getSunday(Date date){  
18.         Calendar cDay = Calendar.getInstance();     
19.         cDay.setTime(date);  
20.         if(Calendar.DAY_OF_WEEK==cDay.getFirstDayOfWeek()){ //如果剛好是周日，直接返回  
21.             return date;  
22.         }else{//如果不是周日,，加一周計算  
23.             cDay.add(Calendar.DAY_OF_YEAR, 7);  
24.             cDay.set(Calendar.DAY_OF_WEEK, 1);  
25.             System.out.println(cDay.getTime());  
26.             return cDay.getTime();  
27.         }    
28.     }  
29.     /** 
30.      * 得到本月第一天的日期 
31.      * @Methods Name getFirstDayOfMonth 
32.      * @return Date 
33.      */  
34.     public Date getFirstDayOfMonth(Date date)   {     
35.         Calendar cDay = Calendar.getInstance();     
36.         cDay.setTime(date);  
37.         cDay.set(Calendar.DAY_OF_MONTH, 1);  
38.         System.out.println(cDay.getTime());  
39.         return cDay.getTime();     
40.     }     
41.     /** 
42.      * 得到本月最后一天的日期 
43.      * @Methods Name getLastDayOfMonth 
44.      * @return Date 
45.      */  
46.     public Date getLastDayOfMonth(Date date)   {     
47.         Calendar cDay = Calendar.getInstance();     
48.         cDay.setTime(date);  
49.         cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMaximum(Calendar.DAY_OF_MONTH));  
50.         System.out.println(cDay.getTime());  
51.         return cDay.getTime();     
52.     }  
53.     /** 
54.      * 得到本季度第一天的日期 
55.      * @Methods Name getFirstDayOfQuarter 
56.      * @return Date 
57.      */  
58.     public Date getFirstDayOfQuarter(Date date)   {     
59.         Calendar cDay = Calendar.getInstance();     
60.         cDay.setTime(date);  
61.         int curMonth = cDay.get(Calendar.MONTH);  
62.         if (curMonth >= Calendar.JANUARY && curMonth <= Calendar.MARCH){    
63.             cDay.set(Calendar.MONTH, Calendar.JANUARY);  
64.         }  
65.         if (curMonth >= Calendar.APRIL && curMonth <= Calendar.JUNE){    
66.             cDay.set(Calendar.MONTH, Calendar.APRIL);  
67.         }  
68.         if (curMonth >= Calendar.JULY && curMonth <= Calendar.AUGUST) {    
69.             cDay.set(Calendar.MONTH, Calendar.JULY);  
70.         }  
71.         if (curMonth >= Calendar.OCTOBER && curMonth <= Calendar.DECEMBER) {    
72.             cDay.set(Calendar.MONTH, Calendar.OCTOBER);  
73.         }  
74.         cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMinimum(Calendar.DAY_OF_MONTH));  
75.         System.out.println(cDay.getTime());  
76.         return cDay.getTime();     
77.     }  
78.     /** 
79.      * 得到本季度最后一天的日期 
80.      * @Methods Name getLastDayOfQuarter 
81.      * @return Date 
82.      */  
83.     public Date getLastDayOfQuarter(Date date)   {     
84.         Calendar cDay = Calendar.getInstance();     
85.         cDay.setTime(date);  
86.         int curMonth = cDay.get(Calendar.MONTH);  
87.         if (curMonth >= Calendar.JANUARY && curMonth <= Calendar.MARCH){    
88.             cDay.set(Calendar.MONTH, Calendar.MARCH);  
89.         }  
90.         if (curMonth >= Calendar.APRIL && curMonth <= Calendar.JUNE){    
91.             cDay.set(Calendar.MONTH, Calendar.JUNE);  
92.         }  
93.         if (curMonth >= Calendar.JULY && curMonth <= Calendar.AUGUST) {    
94.             cDay.set(Calendar.MONTH, Calendar.AUGUST);  
95.         }  
96.         if (curMonth >= Calendar.OCTOBER && curMonth <= Calendar.DECEMBER) {    
97.             cDay.set(Calendar.MONTH, Calendar.DECEMBER);  
98.         }  
99.         cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMaximum(Calendar.DAY_OF_MONTH));  
100.         System.out.println(cDay.getTime());  
101.         return cDay.getTime();     
102.     }