java取当前周期、月初至月末、季度初至季度末日期。

一、

    Calendar calendar = new GregorianCalendar();  

        // 1. 当前登陆日期的周一至周五的日期 比如 现在是2012-06-11 周一是2012-06-11 周五就是 2012-06-15。  

            calendar.set(Calendar.DAY_OF_WEEK, 2);  

            System.out.println("登录日期的周一：" + print(calendar.getTime()));  

            // 2.星期五，第六天s  

            calendar.set(Calendar.DAY_OF_WEEK, 6);  

            System.out.println("登录日期的周五：" + print(calendar.getTime()));  

            // 3.当前月的第一天  

            calendar.set(Calendar.DAY_OF_MONTH, 1);  

            System.out.println("当前月的第一天：" + print(calendar.getTime()));  

            // 4.当前月的最后一天  

            calendar.add(Calendar.MONTH, 1);  

            calendar.set(Calendar.DAY_OF_MONTH, 0);  

            System.out.println("当前月的最后一天：" + print(calendar.getTime()));  

      

            // 季度初  

            calendar.setTime(new Date());  

            int month = getQuarterInMonth(calendar.get(Calendar.MONTH), true);  

            calendar.set(Calendar.MONTH, month);  

            calendar.set(Calendar.DAY_OF_MONTH, 1);  

            System.out.println("当季度的第一天：" + print(calendar.getTime()));  

            // 季度末  

            calendar.setTime(new Date());  

            month = getQuarterInMonth(calendar.get(Calendar.MONTH), false);  

            calendar.set(Calendar.MONTH, month + 1);  

            calendar.set(Calendar.DAY_OF_MONTH, 0);  

            System.out.println("当前时间的季度末：" + print(calendar.getTime()));  

        }  

      

        private static String print(Date d) {  

            DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  

            return df.format(d);  

        }  

      

        // 返回第几个月份，不是几月  

        // 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  

        private static int getQuarterInMonth(int month, boolean isQuarterStart) {  

            int months[] = { 1, 4, 7, 10 };  

            if (!isQuarterStart) {  

                months = new int[] { 3, 6, 9, 12 };  

            }  

            if (month >= 2 && month <= 4)  

                return months[0];  

            else if (month >= 5 && month <= 7)  

                return months[1];  

            else if (month >= 8 && month <= 10)  

                return months[2];  

            else  

                return months[3];  

        }  

二、

    /**

         * 获取指定日期所在周的周一

         * @Methods Name getMonday

         * @return Date

         */  

        public Date getMonday(Date date){  

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);     

            cDay.set(Calendar.DAY_OF_WEEK, 2);//老外将周日定位第一天，周一取第二天  

            return cDay.getTime();     

        }  

        /**

         * 获取指定日期所在周日

         * @Methods Name getSunday

         * @return Date

         */  

        public Date getSunday(Date date){  

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);  

            if(Calendar.DAY_OF_WEEK==cDay.getFirstDayOfWeek()){ //如果刚好是周日，直接返回  

                return date;  

            }else{//如果不是周日，加一周计算  

                cDay.add(Calendar.DAY_OF_YEAR, 7);  

                cDay.set(Calendar.DAY_OF_WEEK, 1);  

                System.out.println(cDay.getTime());  

                return cDay.getTime();  

            }    

        }  

        /**

         * 得到本月第一天的日期

         * @Methods Name getFirstDayOfMonth

         * @return Date

         */  

        public Date getFirstDayOfMonth(Date date)   {     

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);  

            cDay.set(Calendar.DAY_OF_MONTH, 1);  

            System.out.println(cDay.getTime());  

            return cDay.getTime();     

        }     

        /**

         * 得到本月最后一天的日期

         * @Methods Name getLastDayOfMonth

         * @return Date

         */  

        public Date getLastDayOfMonth(Date date)   {     

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);  

            cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMaximum(Calendar.DAY_OF_MONTH));  

            System.out.println(cDay.getTime());  

            return cDay.getTime();     

        }  

        /**

         * 得到本季度第一天的日期

         * @Methods Name getFirstDayOfQuarter

         * @return Date

         */  

        public Date getFirstDayOfQuarter(Date date)   {     

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);  

            int curMonth = cDay.get(Calendar.MONTH);  

            if (curMonth >= Calendar.JANUARY && curMonth <= Calendar.MARCH){    

                cDay.set(Calendar.MONTH, Calendar.JANUARY);  

            }  

            if (curMonth >= Calendar.APRIL && curMonth <= Calendar.JUNE){    

                cDay.set(Calendar.MONTH, Calendar.APRIL);  

            }  

            if (curMonth >= Calendar.JULY && curMonth <= Calendar.AUGUST) {    

                cDay.set(Calendar.MONTH, Calendar.JULY);  

            }  

            if (curMonth >= Calendar.OCTOBER && curMonth <= Calendar.DECEMBER) {    

                cDay.set(Calendar.MONTH, Calendar.OCTOBER);  

            }  

            cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMinimum(Calendar.DAY_OF_MONTH));  

            System.out.println(cDay.getTime());  

            return cDay.getTime();     

        }  

        /**

         * 得到本季度最后一天的日期

         * @Methods Name getLastDayOfQuarter

         * @return Date

         */  

        public Date getLastDayOfQuarter(Date date)   {     

            Calendar cDay = Calendar.getInstance();     

            cDay.setTime(date);  

            int curMonth = cDay.get(Calendar.MONTH);  

            if (curMonth >= Calendar.JANUARY && curMonth <= Calendar.MARCH){    

                cDay.set(Calendar.MONTH, Calendar.MARCH);  

            }  

            if (curMonth >= Calendar.APRIL && curMonth <= Calendar.JUNE){    

                cDay.set(Calendar.MONTH, Calendar.JUNE);  

            }  

            if (curMonth >= Calendar.JULY && curMonth <= Calendar.AUGUST) {    

                cDay.set(Calendar.MONTH, Calendar.AUGUST);  

            }  

            if (curMonth >= Calendar.OCTOBER && curMonth <= Calendar.DECEMBER) {    

                cDay.set(Calendar.MONTH, Calendar.DECEMBER);  

            }  

            cDay.set(Calendar.DAY_OF_MONTH, cDay.getActualMaximum(Calendar.DAY_OF_MONTH));  

            System.out.println(cDay.getTime());  

            return cDay.getTime();     

        }