• 关于Calendar的一些用法总结


    import java.util.Calendar;

    import java.security.KeyStore.TrustedCertificateEntry;

    import java.text.DateFormat;

    import java.text.ParseException;

    import java.text.ParsePosition;   

    import java.text.SimpleDateFormat;   

    import java.util.Calendar;   

    import java.util.Date;   

    import java.util.GregorianCalendar;   

       

    /** 

     * 常用日历操作辅助类 

     * 

     * 

     */   

    public class CalendarUtil {   

       

        // 用来全局控制 上一周,本周,下一周的周数变化   

        private int weeks = 0;   

        private int MaxDate;// 一月最大天数   

        private int MaxYear;// 一年最大天数   

        private static Calendar calendar = Calendar.getInstance();//实例化日历   

       

        /**测试 

         * @param args 

         */   

        public static void main(String[] args) {   

                    CalendarUtil tt = new CalendarUtil();

            

             

            System.out.println("获取当天日期:" + tt.getNowTime("yyyy-MM-dd HH:mm:ss"));

         

            //-------------------------------------------------------------

            System.out.println("获取本周一日期:" + tt.getMondayOFWeek());

            System.out.println("获取本周日的日期:" + tt.getSundayWeekday());

            System.out.println("获取上周日日期:" + tt.getPreviousWeekSunday()); 

            System.out.println("获取上周一日期:" + tt.getPreviousWeekday());      

            System.out.println("获取下周一日期:" + tt.getNextMonday());   

            System.out.println("获取下周日日期:" + tt.getNextSunday());   

            //-------------------------------------------------------------

            System.out.println("获取本月第一天日期:" + tt.getFirstDayOfMonth());   

            System.out.println("获取本月最后一天日期:" + tt.getDefaultDay());   

            System.out.println("获取上月第一天日期:" + tt.getPreviousMonthFirst());   

            System.out.println("获取上月最后一天的日期:" + tt.getPreviousMonthEnd());   

            System.out.println("获取下月第一天日期:" + tt.getNextMonthFirst());   

            System.out.println("获取下月最后一天日期:" + tt.getNextMonthEnd());

            //-------------------------------------------------------------

           

            System.out.println("---------------->");   

            System.out.println("获取当前月的第几周:" + tt.getWeekOfMonth());   

            System.out.println("获取当前年份:" + tt.getYear());

            System.out.println("获得本年有多少天:"+tt.getMaxYear());

            System.out.println("获取当前月份:" + tt.getMonth());

            System.out.println("根据日期获得当天周几:" + tt.getWeek("2018-10-15"));

            System.out.println("获取今天在本年的第几天:" + tt.getDayOfYear()); 

            System.out.println("获得今天在本月的第几天(获得当前日):" + tt.getDayOfMonth());   

            System.out.println("获得今天在本周的第几天:" + tt.getDayOfWeek());   

            System.out.println("获取两个日期之间间隔天数2018-5-1~2018-4-1:"   

                    + CalendarUtil.getTwoDay("2018-5-1", "2018-4-1"));

            System.out.println("获得半年后的日期:" + tt.convertDateToString(tt.getTimeYearNext()));

           

            //-------------------------------------------------------------

           

            System.out.println("获取本年的第一天日期:" + tt.getCurrentYearFirst());   

            System.out.println("获取本年最后一天日期:" + tt.getCurrentYearEnd());   

            System.out.println("获取去年的第一天日期:" + tt.getPreviousYearFirst());   

            System.out.println("获取去年的最后一天日期:" + tt.getPreviousYearEnd());   

            System.out.println("获取明年第一天日期:" + tt.getNextYearFirst());   

            System.out.println("获取明年最后一天日期:" + tt.getNextYearEnd()); 

            //-------------------------季度需单独运行,否则会受之前日期的影响------------------------------------ 

            //System.out.println("获取本季度第一天:" + tt.getThisSeasonFirstTime());   

            //System.out.println("获取本季度最后一天:" + tt.getThisSeasonFinallyTime()); 

            //-------------------------------------------------------------

            

            System.out.println("得到几天前的日期:"+ tt.getDateBefore("2018-6-15", 20));

        }   

       

        // 获取当天时间   

        public String getNowTime(String dateformat) {//传入参数为日期的格式   

            Date now = new Date();   

            SimpleDateFormat dateFormat = new SimpleDateFormat(dateformat);// 可以方便地修改日期格式   

            String toDay = dateFormat.format(now);   

            return toDay;   

        }   

       

        // 获得本周一的日期   

        public String getMondayOFWeek() {   

            CalendarUtil tt = new CalendarUtil();   

            int mondayPlus =tt.getMondayPlus();//调用getMondayPlus方法获得当前日期与本周一相差的天数  

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus); //当天天数与相差的天数进行相加得到周一在本周的天数

            Date monday = currentDate.getTime();  //根据天数获得时间 

           

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }

        // 获得当前日期与本周一相差的天数   

        private int getMondayPlus() {   

            Calendar cd = Calendar.getInstance();   

            // 获得今天是一周的第几天,星期日是第一天,星期一是第二天......   

            int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK) - 1; // 因为按中国礼拜一作为第一天所以这里减1   

            if (dayOfWeek == 1) {   

                return 0;    //如果是周一 返回0(无相差天数)

            } else {   

                     //返回与周一相差的天数(用以当天和相差天数计算)

                     //如果今天为周五 首先dayOfWeek == 5, 1-5则返回-4,当前减去4天就为周一的日期

                return 1 - dayOfWeek;  

            }   

        }   

        // 获得本周星期日的日期   

        public String getSundayWeekday() {   

            int mondayPlus = this.getMondayPlus();

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus + 6); //当天天数与相差的天数进行相加得到周日在本周的天数   

            Date monday = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }

        // 获得上周星期日的日期   

        public String getPreviousWeekSunday() {   

            weeks = 0;   

            weeks--;   

            int mondayPlus = this.getMondayPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus + weeks); //本周周一的天数减去1天 

            Date monday = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }   

       

        // 获得上周星期一的日期   

        public String getPreviousWeekday() {   

            weeks--;   

            int mondayPlus = this.getMondayPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks);//本周周一的天数减去7天   

            Date monday = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }   

       

        // 获得下周星期一的日期   

        public String getNextMonday() {   

            weeks++;   

            int mondayPlus = this.getMondayPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7);//本周周一的天数加7天       

            Date monday = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }

        // 获得下周星期日的日期   

        public String getNextSunday() {   

       

            int mondayPlus = this.getMondayPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 + 6);   

            Date monday = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preMonday = df.format(monday);   

            return preMonday;   

        }

        //----------------------------------------------------------

       

        // 获取当月第一天   

        public String getFirstDayOfMonth() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.set(Calendar.DATE, 1);// 设为当前月的1号   

            str = sdf.format(date.getTime());   

            return str;   

        }   

       

        // 计算当月最后一天,返回字符串   

        public String getDefaultDay() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.set(Calendar.DATE, 1);// 设为当前月的1号   

            date.add(Calendar.MONTH, 1);// 加一个月,变为下月的1号   

            date.add(Calendar.DATE, -1);// 减去一天,变为当月最后一天   

            str = sdf.format(date.getTime());   

            return str;   

        }  

       

        // 上月第一天   

        public String getPreviousMonthFirst() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.set(Calendar.DATE, 1);// 设为当前月的1号   

            date.add(Calendar.MONTH, -1);// 减一个月,变为上月的1号   

       

            str = sdf.format(date.getTime());   

            return str;   

        }  

       

        // 获得上月最后一天的日期   

        public String getPreviousMonthEnd() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.add(Calendar.MONTH, -1);// 减一个月   

            date.set(Calendar.DATE, 1);// 把日期设置为当月第一天   

            date.roll(Calendar.DATE, -1);// 日期回滚一天,也就是本月最后一天   

    //          date.set(Calendar.DATE, 1);

    //          date.add(Calendar.DATE,-1);

            str = sdf.format(date.getTime());   

            return str;   

        }   

       

        // 获得下个月第一天的日期   

        public String getNextMonthFirst() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.add(Calendar.MONTH, 1);// 减一个月   

            date.set(Calendar.DATE, 1);// 把日期设置为当月第一天   

            str = sdf.format(date.getTime());   

            return str;   

        }   

       

        // 获得下个月最后一天的日期   

        public String getNextMonthEnd() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar date = Calendar.getInstance();   

            date.add(Calendar.MONTH, 1);// 加一个月   

            date.set(Calendar.DATE, 1);// 把日期设置为当月第一天   

            date.roll(Calendar.DATE, -1);// 日期回滚一天,也就是本月最后一天   

            str = sdf.format(date.getTime());   

            return str;   

        }   

       

       

        //---------------------------------------------------------

        //获得今天是这个月的第几周  

        public static int getWeekOfMonth() {   

            return calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH);   

        }

        //获得当前年份     

        public static int getYear() {   

            return calendar.get(Calendar.YEAR);   

        }

       

        //获得当前年份     

        public static int getMonth() {   

            return calendar.get(Calendar.MONTH) + 1;   

        }   

       

       

        //获得今天在本年的第几天 

        public static int getDayOfYear() {   

            return calendar.get(Calendar.DAY_OF_YEAR);   

        }   

       

        //获得今天在本月的第几天(获得当前日)   

        public static int getDayOfMonth() {   

            return calendar.get(Calendar.DAY_OF_MONTH);   

        }   

       

        //获得今天在本周的第几天   

        public static int getDayOfWeek() {   

            return calendar.get(Calendar.DAY_OF_WEEK);   

        }   

       

       //得到二个日期间的间隔天数

        public static String getTwoDay(String sj1, String sj2) {   

            SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");   

            long day = 0;   

            try {   

                java.util.Date date = myFormatter.parse(sj1);   

                java.util.Date mydate = myFormatter.parse(sj2);   

                day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);   

            } catch (Exception e) {   

                return "";   

            }   

            return day + "";   

        }

       

        //获得半年后的日期 

        public static Date getTimeYearNext() {   

            calendar.add(Calendar.DAY_OF_YEAR, 183);   

            return calendar.getTime();   

        }   

           

        public static String convertDateToString(Date dateTime){   

            SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");   

            return df.format(dateTime);   

        }   

           

       

        //---------------------------------------------------------------

       

        private int getYearPlus() {   

            Calendar cd = Calendar.getInstance();   

            int yearOfNumber = cd.get(Calendar.DAY_OF_YEAR);// 获得当天是一年中的第几天   

            cd.set(Calendar.DAY_OF_YEAR, 1);// 把日期设为当年第一天   

            cd.roll(Calendar.DAY_OF_YEAR, -1);// 把日期回滚一天。   

            int MaxYear = cd.get(Calendar.DAY_OF_YEAR);   

            if (yearOfNumber == 1) {   

                return -MaxYear;   

            } else {   

                return 1 - yearOfNumber;   

            }   

        }

        // 获得本年第一天的日期   

        public String getCurrentYearFirst() {   

            int yearPlus = this.getYearPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, yearPlus);   

            Date yearDay = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preYearDay = df.format(yearDay);   

            return preYearDay;   

        }   

       

        // 获得本年最后一天的日期 *   

        public String getCurrentYearEnd() {   

            Date date = new Date();   

            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式   

            String years = dateFormat.format(date);   

            return years + "-12-31";   

        }   

       

        // 获得上年第一天的日期 *   

        public String getPreviousYearFirst() {   

            Date date = new Date();   

            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式   

            String years = dateFormat.format(date);   

            int years_value = Integer.parseInt(years);   

            years_value--;   

            return years_value + "-1-1";   

        }   

       

        // 获得上年最后一天的日期   

        public String getPreviousYearEnd() {   

            weeks--;   

            int yearPlus = this.getYearPlus();   

            GregorianCalendar currentDate = new GregorianCalendar();   

            currentDate.add(GregorianCalendar.DATE, yearPlus + MaxYear * weeks   

                    + (MaxYear - 1));   

            Date yearDay = currentDate.getTime();   

            DateFormat df = DateFormat.getDateInstance();   

            String preYearDay = df.format(yearDay);   

            return preYearDay;   

        }   

        // 获得明年最后一天的日期   

        public String getNextYearEnd() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar lastDate = Calendar.getInstance();   

            lastDate.add(Calendar.YEAR, 1);// 加一个年   

            lastDate.set(Calendar.DAY_OF_YEAR, 1);   

            lastDate.roll(Calendar.DAY_OF_YEAR, -1);   

            str = sdf.format(lastDate.getTime());   

            return str;   

        }   

       

        // 获得明年第一天的日期   

        public String getNextYearFirst() {   

            String str = "";   

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");   

       

            Calendar lastDate = Calendar.getInstance();   

            lastDate.add(Calendar.YEAR, 1);// 加一个年   

            lastDate.set(Calendar.DAY_OF_YEAR, 1);   

            str = sdf.format(lastDate.getTime());   

            return str;   

        }   

       

        // 获得本季度第一天   

        public String getThisSeasonFirstTime() {  

                 int month = calendar.get(Calendar.MONTH) + 1;

            int array[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { 10, 11, 12 } };   

            int season = 1;   

            if (month >= 1 && month <= 3) {   

                season = 1;   

            }   

            if (month >= 4 && month <= 6) {   

                season = 2;   

            }   

            if (month >= 7 && month <= 9) {   

                season = 3;   

            }   

            if (month >= 10 && month <= 12) {   

                season = 4;   

            }   

            int start_month = array[season - 1][0];   

            int end_month = array[season - 1][2];   

       

            Date date = new Date();   

            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式   

            String years = dateFormat.format(date);   

            int years_value = Integer.parseInt(years);   

       

            int start_days = 1;

            // years+"-"+String.valueOf(start_month)+"-1";//getLastDayOfMonth(years_value,start_month);   

            int end_days = getLastDayOfMonth(years_value, end_month);   

            String seasonDate = years_value + "-" + start_month + "-" + start_days;   

            return seasonDate;   

       

        }   

       

        // 获得本季度最后一天   

        public String getThisSeasonFinallyTime() {

                 int month =calendar.get(Calendar.MONTH) + 1;

            int array[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { 10, 11, 12 } };   

            int season = 1;   

            if (month >= 1 && month <= 3) {   

                season = 1;   

            }   

            if (month >= 4 && month <= 6) {   

                season = 2;   

            }   

            if (month >= 7 && month <= 9) {   

                season = 3;   

            }   

            if (month >= 10 && month <= 12) {   

                season = 4;   

            }   

            int start_month = array[season - 1][0];   

            int end_month = array[season - 1][2];   

       

            Date date = new Date();   

            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式   

            String years = dateFormat.format(date);   

            int years_value = Integer.parseInt(years);   

       

            int start_days = 1;// years+"-"+String.valueOf(start_month)+"-1";//getLastDayOfMonth(years_value,start_month);   

            int end_days = getLastDayOfMonth(years_value, end_month);   

            String seasonDate = years_value + "-" + end_month + "-" + end_days;   

            return seasonDate;   

        }   

       

        //------------------------------------------------------------------------------

       

       

       

        //根据一个日期,返回是星期几的字符串     

        public static String getWeek(String sdate) {   

            // 再转换为时间   

            Date date = CalendarUtil.strToDate(sdate);   

            Calendar c = Calendar.getInstance();   

            c.setTime(date);   

            // int hour=c.get(Calendar.DAY_OF_WEEK);   

            // hour中存的就是星期几了,其范围 1~7   

            // 1=星期日 7=星期六,其他类推   

            return new SimpleDateFormat("EEEE").format(c.getTime());    //EEEE代表星期几

        }   

       

       

        //将短时间格式字符串转换为时间 yyyy-MM-dd 

        public static Date strToDate(String strDate) {   

            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");   

            ParsePosition pos = new ParsePosition(0);   

            Date strtodate = formatter.parse(strDate, pos);   

            return strtodate;   

        }   

       

       

       

       

     /*   private int getMonthPlus() {   

            Calendar cd = Calendar.getInstance();   

            int monthOfNumber = cd.get(Calendar.DAY_OF_MONTH);   

            cd.set(Calendar.DATE, 1);// 把日期设置为当月第一天   

            cd.roll(Calendar.DATE, -1);// 日期回滚一天,也就是最后一天   

            MaxDate = cd.get(Calendar.DATE);   

            if (monthOfNumber == 1) {   

                return -MaxDate;   

            } else {   

                return 1 - monthOfNumber;   

            }   

        }    */

       

       

        // 获得本年有多少天   

        private int getMaxYear() {   

            Calendar cd = Calendar.getInstance();   

            cd.set(Calendar.DAY_OF_YEAR, 1);// 把日期设为当年第一天   

            cd.roll(Calendar.DAY_OF_YEAR, -1);// 把日期回滚一天。   

            int MaxYear = cd.get(Calendar.DAY_OF_YEAR);   

            return MaxYear;   

        }   

       

       

        //获取某年某月的最后一天 

        private int getLastDayOfMonth(int year, int month) {   

            if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8   

                    || month == 10 || month == 12) {   

                return 31;   

            }   

            if (month == 4 || month == 6 || month == 9 || month == 11) {   

                return 30;   

            }   

            if (month == 2) {   

                if (isLeapYear(year)) {   

                    return 29;//闰年   

                } else {   

                    return 28; //平年     

                }   

            }   

            return 0;   

        }    

        /**

         * 计算闰年和平年

         * 闰年二月是29天,但不是能被4整除的就是闰年

         * @param year

         * @return

         */

        private boolean isLeapYear(int year) {

                 boolean ison = true;

                  if((year%4==0&&year%100!=0)||year%400==0) {

                            ison = true;//闰年   

                  }else {

                         ison = false;//平年   

                  }     

                  return ison;

        }

          

        //系统当前时间

        public static String getCurrentDate (){ 

             

            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); 

            return sdf.format(calendar.getTime()); 

        } 

               //得到几天前的时间 

               public static String getDateBefore(String d,int day){ 

                Calendar date =Calendar.getInstance(); 

                Date dd = strToDate(d);

                date.setTime(dd); 

                date.set(Calendar.DATE,date.get(Calendar.DATE)-day);  

                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); 

           return sdf.format(date.getTime());

               } 

       

    /*       //得到几天后的时间 

               public static Date getDateAfter(Date d,int day){ 

                          Calendar now =Calendar.getInstance(); 

                          now.setTime(d); 

                          now.set(Calendar.DATE,now.get(Calendar.DATE)+day); 

                          return now.getTime(); 

               } */

                    //计算月份差 

                       public static int getMonthSpace(String firstTime,String lastTime) {

                               

                           SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd"); 

                          

                           Calendar c1 = Calendar.getInstance(); 

                           Calendar c2 = Calendar.getInstance(); 

                           try { 

                               c1.setTime(sdf.parse(lastTime)); 

                               c2.setTime(sdf.parse(firstTime)); 

                           } catch (ParseException e) { 

                               e.printStackTrace();         

                           } 

                            

                           int result =(c1.get(Calendar.YEAR)-c2.get(Calendar.YEAR))*12+(c1.get(Calendar.MONTH)-c2.get(Calendar.MONTH));

                            

                                    return result ==0 ? 1 : result; 

             }

    }

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  • 原文地址:https://www.cnblogs.com/hujunhui/p/9186906.html
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