Java对日期Date类进行加减运算、年份加减月份加减、时间差等等
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2024-03-08 17:56:16
实现代码一:
import java.text.simpledateformat;
import java.util.calendar;
import jav...
实现代码一:
import java.text.simpledateformat; import java.util.calendar; import java.util.date; public class datetestutil { public static void main(string[] args) throws exception { simpledateformat sdf=new simpledateformat("yyyymmdd"); string str="20110823"; date dt=sdf.parse(str); calendar rightnow = calendar.getinstance(); rightnow.settime(dt); rightnow.add(calendar.year,-1);//日期减1年 rightnow.add(calendar.month,3);//日期加3个月 rightnow.add(calendar.day_of_year,10);//日期加10天 date dt1=rightnow.gettime(); string restr = sdf.format(dt1); system.out.println(restr); } }
注:在calendar对象的add方法中,第二个参数为正数表示“加”,负数表示“减”。
代码二: java date 日期加减天数
测试类代码:
import java.text.simpledateformat; import java.util.date; public class datetest { public static void main(string[] arg){ date now = new date(); addandsubtractdaysbygettime(now,-5); addandsubtractdaysbygettime(now,5); addandsubtractdaysbycalendar(now,-5); addandsubtractdaysbycalendar(now,5); } public static date addandsubtractdaysbygettime(date datetime/*待处理的日期*/,int n/*加减天数*/){ //日期格式 simpledateformat df=new simpledateformat("yyyy-mm-dd"); simpledateformat dd=new simpledateformat("yyyy-mm-dd hh:mm:ss"); system.out.println(df.format(new date(datetime.gettime() + n * 24 * 60 * 60 * 1000l))); //system.out.println(dd.format(new date(datetime.gettime() + n * 24 * 60 * 60 * 1000l))); //注意这里一定要转换成long类型,要不n超过25时会出现范围溢出,从而得不到想要的日期值 return new date(datetime.gettime() + n * 24 * 60 * 60 * 1000l); } public static date addandsubtractdaysbycalendar(date datetime/*待处理的日期*/,int n/*加减天数*/){ //日期格式 simpledateformat df=new simpledateformat("yyyy-mm-dd"); simpledateformat dd=new simpledateformat("yyyy-mm-dd hh:mm:ss"); java.util.calendar calstart = java.util.calendar.getinstance(); calstart.settime(datetime); calstart.add(java.util.calendar.day_of_week, n); system.out.println(df.format(calstart.gettime())); //system.out.println(dd.format(calstart.gettime())); return calstart.gettime(); } }
运行结果:
2014-10-06
2014-10-16
2014-10-06
2014-10-16
代码三:
在网上查阅资料,加上自己总结的一些关于date类的工具类。
package com.data.utils; import java.text.simpledateformat; import java.util.calendar; import java.util.date; public class dateformat { /** * 日期减几年 */ public static string dateminusyear(string str) throws exception { simpledateformat sdf = new simpledateformat("yyyymm"); date dt = sdf.parse(str); calendar rightnow = calendar.getinstance(); rightnow.settime(dt); rightnow.add(calendar.year, -1);// 日期减1年 date dt1 = rightnow.gettime(); string restr = sdf.format(dt1); return restr; } /** * 日期加几年 */ public static string dateaddyear(string str) throws exception { simpledateformat sdf = new simpledateformat("yyyymm"); date dt = sdf.parse(str); calendar rightnow = calendar.getinstance(); rightnow.settime(dt); rightnow.add(calendar.year, 1);// 日期加1年 date dt1 = rightnow.gettime(); string restr = sdf.format(dt1); return restr; } /** * 日期减几月 */ public static string dateminusmonth(string str) throws exception { simpledateformat sdf = new simpledateformat("yyyymm"); date dt = sdf.parse(str);//将字符串生成date calendar rightnow = calendar.getinstance(); rightnow.settime(dt);//使用给定的 date 设置此 calendar 的时间。 rightnow.add(calendar.month, -1);// 日期减1个月 date dt1 = rightnow.gettime();//返回一个表示此 calendar 时间值的 date 对象。 string restr = sdf.format(dt1);//将给定的 date 格式化为日期/时间字符串,并将结果添加到给定的 stringbuffer。 return restr; } /** * 日期加几月 */ public static string dateaddmonth(string str) throws exception { simpledateformat sdf = new simpledateformat("yyyymm"); date dt = sdf.parse(str); calendar rightnow = calendar.getinstance(); rightnow.settime(dt); rightnow.add(calendar.month, 1);// 日期加3个月 // rightnow.add(calendar.day_of_year,10);//日期加10天 date dt1 = rightnow.gettime(); string restr = sdf.format(dt1); return restr; } /** * 获取当前年月的第一个月的str * @param str * 201505 * @return 201501 * @throws exception */ public static string dateonemonth(string str) { str = str.substring(0, str.length() - 2); str = str + "01"; return str; } /** * 算出所选月份距离一月份有几个月。 * @param str 201509 * @return 9 */ public static int datedistancemonth(string str) { int i = integer.parseint(str); int j = integer.parseint(dateformat.dateonemonth(str)); system.out.println(i - j); return i - j + 1; } /** * 获取两个时间的时间差,精确到毫秒 * @param str * @return */ public static string timedifference(long start, long end) { long between = end - start; long day = between / (24 * 60 * 60 * 1000); long hour = (between / (60 * 60 * 1000) - day * 24); long min = ((between / (60 * 1000)) - day * 24 * 60 - hour * 60); long s = (between / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60); long ms = (between - day * 24 * 60 * 60 * 1000 - hour * 60 * 60 * 1000 - min * 60 * 1000 - s * 1000); string timedifference = day + "天" + hour + "小时" + min + "分" + s + "秒" + ms + "毫秒"; return timedifference; } } /** * 获取24小时、一周、一个月的起始时间 * * @param timeinterval * : day_time_interval week_time_interval month_time_interval * @return "yyyy-mm-dd hh:mm:ss" */ public static string getstarttime(int timeinterval) { calendar cal = calendar.getinstance(); simpledateformat sdf = new simpledateformat("yyyy-mm-dd hh:mm:ss"); if (day_time_interval == timeinterval) {// 获取24小时的起始时间 cal.set(calendar.hour_of_day, 0); cal.set(calendar.minute, 0); cal.set(calendar.second, 0); string starttime = sdf.format(cal.gettime()); return starttime; } else if (week_time_interval == timeinterval) { int weekday = cal.get(calendar.day_of_week) - 1; cal.add(calendar.date, -weekday); cal.set(calendar.hour_of_day, 0); cal.set(calendar.minute, 0); cal.set(calendar.second, 0); string starttime = sdf.format(cal.gettime()); return starttime; } else if (month_time_interval == timeinterval) { int dayofmonthmin = cal.getactualminimum(calendar.day_of_month); // c.add(calendar.date, -dayofmonth); cal.set(calendar.date, dayofmonthmin); cal.set(calendar.hour_of_day, 0); cal.set(calendar.minute, 0); cal.set(calendar.second, 0); string starttime = sdf.format(cal.gettime()); return starttime; } return null; } /** * 获取24小时、一周、一个月的结束时间 * * @param timeinterval * : day_time_interval week_time_interval month_time_interval * @return "yyyy-mm-dd hh:mm:ss" */ public static string getendtime(int timeinterval) { calendar cal = calendar.getinstance(); cal.settimezone(timezone.gettimezone("gmt+8")); simpledateformat sdf = new simpledateformat("yyyy-mm-dd hh:mm:ss"); if (day_time_interval == timeinterval) { cal.set(calendar.hour_of_day, 23); cal.set(12, 59); cal.set(13, 59); long date = cal.gettimeinmillis(); string endtime = sdf.format(new date(date)); return endtime; } else if (week_time_interval == timeinterval) { int weekday = cal.get(calendar.day_of_week) - 1; cal.add(calendar.date, -weekday); cal.add(calendar.date, 6); cal.set(calendar.hour_of_day, 23); cal.set(12, 59); cal.set(13, 59); long date = cal.gettimeinmillis(); string endtime = sdf.format(new date(date)); return endtime; } else if (month_time_interval == timeinterval) { int dayofmonthmax = cal.getactualmaximum(calendar.day_of_month); cal.set(calendar.date, dayofmonthmax); cal.set(calendar.hour_of_day, 23); cal.set(calendar.minute, 59); cal.set(calendar.second, 59); string endtime = sdf.format(cal.gettime()); return endtime; } return null; } /** * 判断datestr是否在start和end中间,start和end都可以为null yyyymmddhhmmss或者yyyymmdd格式 * * @author you.xu * @date 2015年8月19日下午3:11:46 * @param datestr * @param start * @param end * @return */ public static boolean checkdateval(string datestr, string start, string end) { boolean isdateright = false; date date = null; date startdate = null; date enddate = null; simpledateformat sdf = null; // 判断日期格式 if (14 == datestr.length()) { sdf = new simpledateformat("yyyymmddhhmmss"); } else if (8 == datestr.length()) { sdf = new simpledateformat("yyyymmdd"); } else return false; try { // 更改判断日期格式 date = sdf.parse(datestr); } catch (parseexception e) { log.error(e, e); } if ((start == null) && (end != null)) { try { enddate = sdf.parse(end); } catch (parseexception ex1) { log.error(ex1, ex1); } if ((date != null) && (enddate != null))// check parameters for { if (date.compareto(enddate) <= 0) isdateright = true; } } else if ((start != null) && (end == null)) { try { startdate = sdf.parse(start); } catch (parseexception ex1) { log.error(ex1, ex1); } if ((date != null) && (startdate != null)) { if (date.compareto(startdate) >= 0) isdateright = true; } } else if ((start != null) && (end != null)) { try { startdate = sdf.parse(start); enddate = sdf.parse(end); } catch (parseexception ex2) { system.out.println(ex2.tostring()); } if ((startdate != null) && (date != null) && (enddate != null)) { if ((date.compareto(startdate) >= 0) && (date.compareto(enddate) <= 0)) isdateright = true; } } return isdateright; } /** * 判断datestr是否在start和end中间,start和end都可以为null long形格式 * * @author you.xu * @date 2015年8月19日下午3:12:35 * @param datestr * @param start * @param end * @return */ public static boolean checkdatev(string datestr, string start, string end) { boolean isdateright = false; long date = -1; long fromdate = -1; long todate = -1; date = java.lang.long.parselong(datestr); if ((start == null) && (end == null)) { isdateright = true; } else if ((start == null) && (end != null)) { try { todate = java.lang.long.parselong(end); } catch (numberformatexception nfe) { log.error(nfe, nfe); } if (date <= todate) { isdateright = true; } } else if ((start != null) && (end == null)) { try { fromdate = java.lang.long.parselong(start); } catch (numberformatexception nfe) { log.error(nfe, nfe); } if (date >= fromdate) { isdateright = true; } } else if ((start != null) && (end != null)) { try { todate = java.lang.long.parselong(end); fromdate = java.lang.long.parselong(start); } catch (numberformatexception nfe) { log.error(nfe, nfe); } if ((date <= todate) && (date >= fromdate)) { isdateright = true; } } return isdateright; }
目前就用到了这些,随时添加,有简单方便的时间工具类,希望和大家一起学习,在评论中指出。thanks!!!