Java日期格式转换
1.1 返回时间类型 yyyy-MM-dd HH:mm:ss public static Date getNowDate() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); ParsePosition pos = new ParsePosition(8); Date currentTime_2 = formatter.parse(dateString, pos); return currentTime_2; } 1.2 返回短时间格式 yyyy-MM-dd DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd"); DateFormat format 2= new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒"); Date date = null; String str = null; // String转Date str = "2007-1-18"; try { date = format1.parse(str); data = format2.parse(str); } catch (ParseException e) { e.printStackTrace(); } 1.3 返回字符串格式 yyyy-MM-dd HH:mm:ss public static String getStringDate() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); return dateString; } 1.4 返回短时间字符串格式yyyy-MM-dd public static String getStringDateShort() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); String dateString = formatter.format(currentTime); return dateString; } 1.5 获取时间 小时:分;秒 HH:mm:ss public static String getTimeShort() { SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss"); Date currentTime = new Date(); String dateString = formatter.format(currentTime); return dateString; } 1.6 将长时间格式字符串转换为时间 yyyy-MM-dd HH:mm:ss public static Date strToDateLong(String strDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); ParsePosition pos = new ParsePosition(0); Date strtodate = formatter.parse(strDate, pos); return strtodate; } 1.7 将长时间格式时间转换为字符串 yyyy-MM-dd HH:mm:ss public static String dateToStrLong(java.util.Date dateDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(dateDate); return dateString; } 1.8 将短时间格式时间转换为字符串 yyyy-MM-dd public static String dateToStr(java.util.Date dateDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); String dateString = formatter.format(dateDate); return dateString; } 1.9 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; } 1.10 得到现在时间 public static Date getNow() { Date currentTime = new Date(); return currentTime; } 1.11 提取一个月中的最后一天 public static Date getLastDate(long day) { Date date = new Date(); long date_3_hm = date.getTime() - 3600000 * 34 * day; Date date_3_hm_date = new Date(date_3_hm); return date_3_hm_date; } 1.12 字符串 yyyyMMdd HHmmss public static String getStringToday() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd HHmmss"); String dateString = formatter.format(currentTime); return dateString; } 1.13 得到现在小时 public static String getHour() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); String hour; hour = dateString.substring(11, 13); return hour; } 1.14 得到现在分钟 public static String getTime() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); String min; min = dateString.substring(14, 16); return min; } 1.15 根据用户传入的时间表示格式,返回当前时间的格式 如果是yyyyMMdd,注意字母y不能大写。 public static String getUserDate(String sformat) { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat(sformat); String dateString = formatter.format(currentTime); return dateString; } -------------------------------------------------------------------------------------------------------------------------------- 二、做成方法2.1返回时间类型 yyyy-MM-dd HH:mm:ss public static Date getNowDate() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); ParsePosition pos = new ParsePosition(8); Date currentTime_2 = formatter.parse(dateString, pos); return currentTime_2; } 2.2返回短时间格式 yyyy-MM-dd public static Date getNowDateShort() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); String dateString = formatter.format(currentTime); ParsePosition pos = new ParsePosition(8); Date currentTime_2 = formatter.parse(dateString, pos); return currentTime_2; } 2.3返回字符串格式 yyyy-MM-dd HH:mm:ss public static String getStringDate() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); return dateString; } 2.4返回短时间字符串格式yyyy-MM-dd public static String getStringDateShort() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); String dateString = formatter.format(currentTime); return dateString; } 2.5小时:分;秒 HH:mm:ss public static String getTimeShort() { SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss"); Date currentTime = new Date(); String dateString = formatter.format(currentTime); return dateString; } 2.6将长时间格式字符串转换为时间 yyyy-MM-dd HH:mm:ss public static Date strToDateLong(String strDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); ParsePosition pos = new ParsePosition(0); Date strtodate = formatter.parse(strDate, pos); return strtodate; } 2.7将长时间格式时间转换为字符串 yyyy-MM-dd HH:mm:ss public static String dateToStrLong(java.util.Date dateDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(dateDate); return dateString; } 2.8将短时间格式时间转换为字符串 yyyy-MM-dd public static String dateToStr(java.util.Date dateDate) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); String dateString = formatter.format(dateDate); return dateString; } 2.9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; } 2.10得到现在时间 public static Date getNow() { Date currentTime = new Date(); return currentTime; } 2.11提取一个月中的最后一天 public static Date getLastDate(long day) { Date date = new Date(); long date_3_hm = date.getTime() - 3600000 * 34 * day; Date date_3_hm_date = new Date(date_3_hm); return date_3_hm_date; } 2.12字符串 yyyyMMdd HHmmss public static String getStringToday() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd HHmmss"); String dateString = formatter.format(currentTime); return dateString; } 2.13得到现在小时 public static String getHour() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); String hour; hour = dateString.substring(11, 13); return hour; } 2.14得到现在分钟 public static String getTime() { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String dateString = formatter.format(currentTime); String min; min = dateString.substring(14, 16); return min; } 2.15根据用户传入的时间表示格式,返回当前时间的格式 如果是yyyyMMdd,注意字母y不能大写。 public static String getUserDate(String sformat) { Date currentTime = new Date(); SimpleDateFormat formatter = new SimpleDateFormat(sformat); String dateString = formatter.format(currentTime); return dateString; } 2.16二个小时时间间的差值,必须保证二个时间都是"HH:MM"的格式,返回字符型的分钟 public static String getTwoHour(String st1, String st2) { String[] kk = null; String[] jj = null; kk = st1.split(":"); jj = st2.split(":"); if (Integer.parseInt(kk[0]) < Integer.parseInt(jj[0])) return "0"; else { double y = Double.parseDouble(kk[0]) + Double.parseDouble(kk[1]) / 60; double u = Double.parseDouble(jj[0]) + Double.parseDouble(jj[1]) / 60; if ((y - u) > 0) return y - u + ""; else return "0"; } } 2.17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 + ""; } 2.18时间前推或后推分钟,其中JJ表示分钟 public static String getPreTime(String sj1, String jj) { SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String mydate1 = ""; try { Date date1 = format.parse(sj1); long Time = (date1.getTime() / 1000) + Integer.parseInt(jj) * 60; date1.setTime(Time * 1000); mydate1 = format.format(date1); } catch (Exception e) { } return mydate1; } 2.19得到一个时间延后或前移几天的时间,nowdate为时间,delay为前移或后延的天数 public static String getNextDay(String nowdate, String delay) { try{ SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd"); String mdate = ""; Date d = strToDate(nowdate); long myTime = (d.getTime() / 1000) + Integer.parseInt(delay) * 24 * 60 * 60; d.setTime(myTime * 1000); mdate = format.format(d); return mdate; }catch(Exception e){ return ""; } } 2.20判断是否润年 public static boolean isLeapYear(String ddate) { /** * 详细设计: 1.被400整除是闰年,否则: 2.不能被4整除则不是闰年 3.能被4整除同时不能被100整除则是闰年 * 3.能被4整除同时能被100整除则不是闰年 */ Date d = strToDate(ddate); GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance(); gc.setTime(d); int year = gc.get(Calendar.YEAR); if ((year % 400) == 0) return true; else if ((year % 4) == 0) { if ((year % 100) == 0) return false; else return true; } else return false; } 2.21返回美国时间格式 26 Apr 2006 public static String getEDate(String str) { SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd"); ParsePosition pos = new ParsePosition(0); Date strtodate = formatter.parse(str, pos); String j = strtodate.toString(); String[] k = j.split(" "); return k[2] + k[1].toUpperCase() + k[5].substring(2, 4); } 2.22获取一个月的最后一天 public static String getEndDateOfMonth(String dat) {// yyyy-MM-dd String str = dat.substring(0, 8); String month = dat.substring(5, 7); int mon = Integer.parseInt(month); if (mon == 1 || mon == 3 || mon == 5 || mon == 7 || mon == 8 || mon == 10 || mon == 12) { str += "31"; } else if (mon == 4 || mon == 6 || mon == 9 || mon == 11) { str += "30"; } else { if (isLeapYear(dat)) { str += "29"; } else { str += "28"; } } return str; } 2.23判断二个时间是否在同一个周 public static boolean isSameWeekDates(Date date1, Date date2) { Calendar cal1 = Calendar.getInstance(); Calendar cal2 = Calendar.getInstance(); cal1.setTime(date1); cal2.setTime(date2); int subYear = cal1.get(Calendar.YEAR) - cal2.get(Calendar.YEAR); if (0 == subYear) { if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR)) return true; } else if (1 == subYear && 11 == cal2.get(Calendar.MONTH)) { // 如果12月的最后一周横跨来年第一周的话则最后一周即算做来年的第一周 if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR)) return true; } else if (-1 == subYear && 11 == cal1.get(Calendar.MONTH)) { if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2.get(Calendar.WEEK_OF_YEAR)) return true; } return false; } 2.24产生周序列,即得到当前时间所在的年度是第几周 public static String getSeqWeek() { Calendar c = Calendar.getInstance(Locale.CHINA); String week = Integer.toString(c.get(Calendar.WEEK_OF_YEAR)); if (week.length() == 1) week = "0" + week; String year = Integer.toString(c.get(Calendar.YEAR)); return year + week; } 2.25获得一个日期所在的周的星期几的日期 如要找出2002年2月3日所在周的星期一是几号 public static String getWeek(String sdate, String num) { // 再转换为时间 Date dd = VeDate.strToDate(sdate); Calendar c = Calendar.getInstance(); c.setTime(dd); if (num.equals("1")) // 返回星期一所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); else if (num.equals("2")) // 返回星期二所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.TUESDAY); else if (num.equals("3")) // 返回星期三所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY); else if (num.equals("4")) // 返回星期四所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.THURSDAY); else if (num.equals("5")) // 返回星期五所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY); else if (num.equals("6")) // 返回星期六所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY); else if (num.equals("0")) // 返回星期日所在的日期 c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY); return new SimpleDateFormat("yyyy-MM-dd").format(c.getTime()); } 2.26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 = VeDate.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 String getWeekStr(String sdate){ String str = ""; str = VeDate.getWeek(sdate); if("1".equals(str)){ str = "星期日"; }else if("2".equals(str)){ str = "星期一"; }else if("3".equals(str)){ str = "星期二"; }else if("4".equals(str)){ str = "星期三"; }else if("5".equals(str)){ str = "星期四"; }else if("6".equals(str)){ str = "星期五"; }else if("7".equals(str)){ str = "星期六"; } return str; } 2.27两个时间之间的天数 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; } 2.28形成特殊的日历 根据传入的一个时间返回一个结构 星期日 星期一 星期二 星期三 星期四 星期五 星期六 下面是当月的各个时间 此函数返回该日历第一行星期日所在的日期 public static String getNowMonth(String sdate) { // 取该时间所在月的一号 sdate = sdate.substring(0, 8) + "01"; // 得到这个月的1号是星期几 Date date = VeDate.strToDate(sdate); Calendar c = Calendar.getInstance(); c.setTime(date); int u = c.get(Calendar.DAY_OF_WEEK); String newday = VeDate.getNextDay(sdate, (1 - u) + ""); return newday; } 2.29取得数据库主键 生成格式为yyyymmddhhmmss+k位随机数 public static String getNo(int k) { return getUserDate("yyyyMMddhhmmss") + getRandom(k); }