java 日期 Date 操作总结
1：
Java对日期Date类进行加减运算，年份加减，月份加减
/** * 日期操作 * @param date 修改日期的字符串 》》“20140103” * @param addYears 加X年 X，减X年 -X，不加 0； * @param addMonths 加X月 X，减X月-X，不加 0； * @param addDays 加X日 X，减X日 -X，不加 0； * @param dateFormat 修改后的时间格式 》》“yyyyMMdd”； * @return 修改后的日期 * @author JiaRH * @Date 2014/01/03 09:50 */ public static String getDate(String date,int addYears,int addMonths,int addDays,String dateFormat){ SimpleDateFormat sdf=new SimpleDateFormat(dateFormat); Date dt; try { dt = sdf.parse(date); Calendar calendar = Calendar.getInstance(); calendar.setTime(dt); calendar.add(Calendar.YEAR,addYears); calendar.add(Calendar.MONTH,addMonths); calendar.add(Calendar.DAY_OF_YEAR,addDays); Date newDate=calendar.getTime(); return sdf.format(newDate); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; }
2：// 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 public static void main(String[] args) { MyTestDate tt = new MyTestDate(); System.out.println("获取当天日期:" + tt.getNowTime("yyyy-MM-dd")); System.out.println("获取本周一日期:" + tt.getMondayOFWeek()); System.out.println("获取本周日的日期~:" + tt.getCurrentWeekday()); System.out.println("获取上周一日期:" + tt.getPreviousWeekday()); System.out.println("获取上周日日期:" + tt.getPreviousWeekSunday()); 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("获得相应周的周六的日期:" + tt.getNowTime("yyyy-MM-dd")); 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("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()); System.out.println("获取本季度第一天到最后一天:" + tt.getThisSeasonTime(11)); System.out.println("获取两个日期之间间隔天数2008-12-1~2008-9.29:" + MyTestDate.getTwoDay("2008-12-1", "2008-9-29")); } 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 + ""; } public static String getWeek(String sdate) { // 再转换为时间 Date date = MyTestDate.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()); } 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; } public static long getDays(String date1, String date2) { if (date1 == null || date1.equals("")) return 0; if (date2 == null || date2.equals("")) return 0; // 转换为标准时间 SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd"); java.util.Date date = null; java.util.Date mydate = null; try { date = myFormatter.parse(date1); mydate = myFormatter.parse(date2); } catch (Exception e) { } long day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000); return day; } // 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 lastDate = Calendar.getInstance(); lastDate.set(Calendar.DATE, 1);// 设为当前月的1号 lastDate.add(Calendar.MONTH, 1);// 加一个月，变为下月的1号 lastDate.add(Calendar.DATE, -1);// 减去一天，变为当月最后一天 str = sdf.format(lastDate.getTime()); return str; } // 上月第一天 public String getPreviousMonthFirst() { String str = ""; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); Calendar lastDate = Calendar.getInstance(); lastDate.set(Calendar.DATE, 1);// 设为当前月的1号 lastDate.add(Calendar.MONTH, -1);// 减一个月，变为下月的1号 // lastDate.add(Calendar.DATE,-1);//减去一天，变为当月最后一天 str = sdf.format(lastDate.getTime()); return str; } // 获取当月第一天 public String getFirstDayOfMonth() { String str = ""; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); Calendar lastDate = Calendar.getInstance(); lastDate.set(Calendar.DATE, 1);// 设为当前月的1号 str = sdf.format(lastDate.getTime()); return str; } // 获得本周星期日的日期 public String getCurrentWeekday() { weeks = 0; int mondayPlus = this.getMondayPlus(); GregorianCalendar currentDate = new GregorianCalendar(); currentDate.add(GregorianCalendar.DATE, mondayPlus + 6); Date monday = currentDate.getTime(); DateFormat df = DateFormat.getDateInstance(); String preMonday = df.format(monday); return preMonday; } // 获取当天时间 public String getNowTime(String dateformat) { Date now = new Date(); SimpleDateFormat dateFormat = new SimpleDateFormat(dateformat);// 可以方便地修改日期格式 String hehe = dateFormat.format(now); return hehe; } // 获得当前日期与本周日相差的天数 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，星期二是第二天...... 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; } else { return 1 - dayOfWeek; } } // 获得本周一的日期 public String getMondayOFWeek() { weeks = 0; int mondayPlus = this.getMondayPlus(); GregorianCalendar currentDate = new GregorianCalendar(); currentDate.add(GregorianCalendar.DATE, mondayPlus); Date monday = currentDate.getTime(); DateFormat df = DateFormat.getDateInstance(); String preMonday = df.format(monday); return preMonday; } // 获得相应周的周六的日期 public String getSaturday() { int mondayPlus = this.getMondayPlus(); GregorianCalendar currentDate = new GregorianCalendar(); currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks + 6); 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); 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); 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); 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; } 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; } } // 获得上月最后一天的日期 public String getPreviousMonthEnd() { String str = ""; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); Calendar lastDate = Calendar.getInstance(); lastDate.add(Calendar.MONTH, -1);// 减一个月 lastDate.set(Calendar.DATE, 1);// 把日期设置为当月第一天 lastDate.roll(Calendar.DATE, -1);// 日期回滚一天，也就是本月最后一天 str = sdf.format(lastDate.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 lastDate = Calendar.getInstance(); lastDate.add(Calendar.MONTH, 1);// 减一个月 lastDate.set(Calendar.DATE, 1);// 把日期设置为当月第一天 str = sdf.format(lastDate.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 lastDate = Calendar.getInstance(); lastDate.add(Calendar.MONTH, 1);// 加一个月 lastDate.set(Calendar.DATE, 1);// 把日期设置为当月第一天 lastDate.roll(Calendar.DATE, -1);// 日期回滚一天，也就是本月最后一天 str = sdf.format(lastDate.getTime()); return str; } // 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; } 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); getThisSeasonTime(11); return preYearDay; } // 获得本季度 public String getThisSeasonTime(int month) { 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 + ";" + years_value + "-" + end_month + "-" + end_days; return seasonDate; } 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; } else { return 28; } } return 0; } public boolean isLeapYear(int year) { return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0); }