本文针对日期处理进行学习使用，主要分为两部分，下面为大家具体介绍一下
第一部分：日期处理基础知识
Date 类
作用：最主要的作用就是获得当前时间
将日期转换为标准格式
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Date date = new Date();SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String str = sdf.format(date);System.out.println(“2015-10-16 14:59:52”); |
将String转换为Date类型
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String day = "2014-6-5 10:30:30";SimpleDateFormat d2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");Date date2 = d2.parse(day);System.out.println(“Thu Jun 05 10:30:30 CST 2014”); |
Calendar 类的应用
java.util.Calendar 类是一个抽象类，可以通过调用 getInstance() 静态方法获取一个 Calendar 对象，此对象已由当前日期时间初始化，即默认代表当前时间
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Calendar c = Calendar.getInstance();int year = c.get(Calender.YEAR);int month= c.get(Calender.MONTH)+1; //获取月份，0表示1月份int day = c.get(Calender.DAY_OF_MONTH);int hour= c.get(Calender.HOUR_OF_DAY);int minute= c.get(Calender.MINUTE);int second = c.get(Calender.SECOND); |
比较2个时间相差的月份
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SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");DateTime d1 = new DateTime(format.parse("2016-10-31 00:00:00"));DateTime d2 = new DateTime(format.parse("2015-1-31 00:00:00"));System.out.println(Math.abs(Months.monthsBetween(d1,d2).getMonths())); |
第二部分：日期处理工具类
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package com.analysys.website.control; import java.text.ParseException;import java.text.ParsePosition;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar; import org.apache.commons.lang.StringUtils;import org.apache.log4j.Logger; /** * 日期处理工具类 * @author dylan_xu * @date Mar 11, 2012 * @modified by * @modified date * @since JDK1.6 * @see com.util.DateUtil */ public class DateUtil { // ~ Static fields/initializers // ============================================= private static Logger logger = Logger.getLogger(DateUtil.class); private static String defaultDatePattern = null; private static String timePattern = "HH:mm"; private static Calendar cale = Calendar.getInstance(); public static final String TS_FORMAT = DateUtil.getDatePattern() + " HH:mm:ss.S"; /** 日期格式yyyy-MM字符串常量 */ private static final String MONTH_FORMAT = "yyyy-MM"; /** 日期格式yyyy-MM-dd字符串常量 */ private static final String DATE_FORMAT = "yyyy-MM-dd"; /** 日期格式HH:mm:ss字符串常量 */ private static final String HOUR_FORMAT = "HH:mm:ss"; /** 日期格式yyyy-MM-dd HH:mm:ss字符串常量 */ private static final String DATETIME_FORMAT = "yyyy-MM-dd HH:mm:ss"; /** 某天开始时分秒字符串常量 00:00:00 */ private static final String DAY_BEGIN_STRING_HHMMSS = " 00:00:00"; /** 某天结束时分秒字符串常量 23:59:59 */ public static final String DAY_END_STRING_HHMMSS = " 23:59:59"; private static SimpleDateFormat sdf_date_format = new SimpleDateFormat(DATE_FORMAT); private static SimpleDateFormat sdf_hour_format = new SimpleDateFormat(HOUR_FORMAT); private static SimpleDateFormat sdf_datetime_format = new SimpleDateFormat(DATETIME_FORMAT); // ~ Methods // ================================================================ public DateUtil() { } /** * 获得服务器当前日期及时间，以格式为：yyyy-MM-dd HH:mm:ss的日期字符串形式返回 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getDateTime() { try { return sdf_datetime_format.format(cale.getTime()); } catch (Exception e) { logger.debug("DateUtil.getDateTime():" + e.getMessage()); return ""; } } /** * 获得服务器当前日期，以格式为：yyyy-MM-dd的日期字符串形式返回 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getDate() { try { return sdf_date_format.format(cale.getTime()); } catch (Exception e) { logger.debug("DateUtil.getDate():" + e.getMessage()); return ""; } } /** * 获得服务器当前时间，以格式为：HH:mm:ss的日期字符串形式返回 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getTime() { String temp = " "; try { temp += sdf_hour_format.format(cale.getTime()); return temp; } catch (Exception e) { logger.debug("DateUtil.getTime():" + e.getMessage()); return ""; } } /** * 统计时开始日期的默认值 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getStartDate() { try { return getYear() + "-01-01"; } catch (Exception e) { logger.debug("DateUtil.getStartDate():" + e.getMessage()); return ""; } } /** * 统计时结束日期的默认值 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getEndDate() { try { return getDate(); } catch (Exception e) { logger.debug("DateUtil.getEndDate():" + e.getMessage()); return ""; } } /** * 获得服务器当前日期的年份 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getYear() { try { return String.valueOf(cale.get(Calendar.YEAR)); } catch (Exception e) { logger.debug("DateUtil.getYear():" + e.getMessage()); return ""; } } /** * 获得服务器当前日期的月份 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getMonth() { try { java.text.DecimalFormat df = new java.text.DecimalFormat(); df.applyPattern("00;00"); return df.format((cale.get(Calendar.MONTH) + 1)); } catch (Exception e) { logger.debug("DateUtil.getMonth():" + e.getMessage()); return ""; } } /** * 获得服务器在当前月中天数 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getDay() { try { return String.valueOf(cale.get(Calendar.DAY_OF_MONTH)); } catch (Exception e) { logger.debug("DateUtil.getDay():" + e.getMessage()); return ""; } } /** * 比较两个日期相差的天数 * @author dylan_xu * @date Mar 11, 2012 * @param date1 * @param date2 * @return */ public static int getMargin(String date1, String date2) { int margin; try { ParsePosition pos = new ParsePosition(0); ParsePosition pos1 = new ParsePosition(0); Date dt1 = sdf_date_format.parse(date1, pos); Date dt2 = sdf_date_format.parse(date2, pos1); long l = dt1.getTime() - dt2.getTime(); margin = (int) (l / (24 * 60 * 60 * 1000)); return margin; } catch (Exception e) { logger.debug("DateUtil.getMargin():" + e.toString()); return 0; } } /** * 比较两个日期相差的天数 * @author dylan_xu * @date Mar 11, 2012 * @param date1 * @param date2 * @return */ public static double getDoubleMargin(String date1, String date2) { double margin; try { ParsePosition pos = new ParsePosition(0); ParsePosition pos1 = new ParsePosition(0); Date dt1 = sdf_datetime_format.parse(date1, pos); Date dt2 = sdf_datetime_format.parse(date2, pos1); long l = dt1.getTime() - dt2.getTime(); margin = (l / (24 * 60 * 60 * 1000.00)); return margin; } catch (Exception e) { logger.debug("DateUtil.getMargin():" + e.toString()); return 0; } } /** * 比较两个日期相差的月数 * @author dylan_xu * @date Mar 11, 2012 * @param date1 * @param date2 * @return */ public static int getMonthMargin(String date1, String date2) { int margin; try { margin = (Integer.parseInt(date2.substring(0, 4)) - Integer.parseInt(date1.substring(0, 4))) * 12; margin += (Integer.parseInt(date2.substring(4, 7).replaceAll("-0", "-")) - Integer.parseInt(date1.substring(4, 7).replaceAll("-0", "-"))); return margin; } catch (Exception e) { logger.debug("DateUtil.getMargin():" + e.toString()); return 0; } } /** * 返回日期加X天后的日期 * @author dylan_xu * @date Mar 11, 2012 * @param date * @param i * @return */ public static String addDay(String date, int i) { try { GregorianCalendar gCal = new GregorianCalendar( Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(5, 7)) - 1, Integer.parseInt(date.substring(8, 10))); gCal.add(GregorianCalendar.DATE, i); return sdf_date_format.format(gCal.getTime()); } catch (Exception e) { logger.debug("DateUtil.addDay():" + e.toString()); return getDate(); } } /** * 返回日期加X月后的日期 * @author dylan_xu * @date Mar 11, 2012 * @param date * @param i * @return */ public static String addMonth(String date, int i) { try { GregorianCalendar gCal = new GregorianCalendar( Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(5, 7)) - 1, Integer.parseInt(date.substring(8, 10))); gCal.add(GregorianCalendar.MONTH, i); return sdf_date_format.format(gCal.getTime()); } catch (Exception e) { logger.debug("DateUtil.addMonth():" + e.toString()); return getDate(); } } /** * 返回日期加X年后的日期 * @author dylan_xu * @date Mar 11, 2012 * @param date * @param i * @return */ public static String addYear(String date, int i) { try { GregorianCalendar gCal = new GregorianCalendar( Integer.parseInt(date.substring(0, 4)), Integer.parseInt(date.substring(5, 7)) - 1, Integer.parseInt(date.substring(8, 10))); gCal.add(GregorianCalendar.YEAR, i); return sdf_date_format.format(gCal.getTime()); } catch (Exception e) { logger.debug("DateUtil.addYear():" + e.toString()); return ""; } } /** * 返回某年某月中的最大天 * @author dylan_xu * @date Mar 11, 2012 * @param year * @param month * @return */ public static int getMaxDay(int iyear, int imonth) { int day = 0; try { if (imonth == 1 || imonth == 3 || imonth == 5 || imonth == 7 || imonth == 8 || imonth == 10 || imonth == 12) { day = 31; } else if (imonth == 4 || imonth == 6 || imonth == 9 || imonth == 11) { day = 30; } else if ((0 == (iyear % 4)) && (0 != (iyear % 100)) || (0 == (iyear % 400))) { day = 29; } else { day = 28; } return day; } catch (Exception e) { logger.debug("DateUtil.getMonthDay():" + e.toString()); return 1; } } /** * 格式化日期 * @author dylan_xu * @date Mar 11, 2012 * @param orgDate * @param Type * @param Span * @return */ @SuppressWarnings("static-access") public String rollDate(String orgDate, int Type, int Span) { try { String temp = ""; int iyear, imonth, iday; int iPos = 0; char seperater = '-'; if (orgDate == null || orgDate.length() < 6) { return ""; } iPos = orgDate.indexOf(seperater); if (iPos > 0) { iyear = Integer.parseInt(orgDate.substring(0, iPos)); temp = orgDate.substring(iPos + 1); } else { iyear = Integer.parseInt(orgDate.substring(0, 4)); temp = orgDate.substring(4); } iPos = temp.indexOf(seperater); if (iPos > 0) { imonth = Integer.parseInt(temp.substring(0, iPos)); temp = temp.substring(iPos + 1); } else { imonth = Integer.parseInt(temp.substring(0, 2)); temp = temp.substring(2); } imonth--; if (imonth < 0 || imonth > 11) { imonth = 0; } iday = Integer.parseInt(temp); if (iday < 1 || iday > 31) iday = 1; Calendar orgcale = Calendar.getInstance(); orgcale.set(iyear, imonth, iday); temp = this.rollDate(orgcale, Type, Span); return temp; } catch (Exception e) { return ""; } } public static String rollDate(Calendar cal, int Type, int Span) { try { String temp = ""; Calendar rolcale; rolcale = cal; rolcale.add(Type, Span); temp = sdf_date_format.format(rolcale.getTime()); return temp; } catch (Exception e) { return ""; } } /** * 返回默认的日期格式 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static synchronized String getDatePattern() { defaultDatePattern = "yyyy-MM-dd"; return defaultDatePattern; } /** * 将指定日期按默认格式进行格式代化成字符串后输出如：yyyy-MM-dd * @author dylan_xu * @date Mar 11, 2012 * @param aDate * @return */ public static final String getDate(Date aDate) { SimpleDateFormat df = null; String returnValue = ""; if (aDate != null) { df = new SimpleDateFormat(getDatePattern()); returnValue = df.format(aDate); } return (returnValue); } /** * 取得给定日期的时间字符串，格式为当前默认时间格式 * @author dylan_xu * @date Mar 11, 2012 * @param theTime * @return */ public static String getTimeNow(Date theTime) { return getDateTime(timePattern, theTime); } /** * 取得当前时间的Calendar日历对象 * @author dylan_xu * @date Mar 11, 2012 * @return * @throws ParseException */ public Calendar getToday() throws ParseException { Date today = new Date(); SimpleDateFormat df = new SimpleDateFormat(getDatePattern()); String todayAsString = df.format(today); Calendar cal = new GregorianCalendar(); cal.setTime(convertStringToDate(todayAsString)); return cal; } /** * 将日期类转换成指定格式的字符串形式 * @author dylan_xu * @date Mar 11, 2012 * @param aMask * @param aDate * @return */ public static final String getDateTime(String aMask, Date aDate) { SimpleDateFormat df = null; String returnValue = ""; if (aDate == null) { logger.error("aDate is null!"); } else { df = new SimpleDateFormat(aMask); returnValue = df.format(aDate); } return (returnValue); } /** * 将指定的日期转换成默认格式的字符串形式 * @author dylan_xu * @date Mar 11, 2012 * @param aDate * @return */ public static final String convertDateToString(Date aDate) { return getDateTime(getDatePattern(), aDate); } /** * 将日期字符串按指定格式转换成日期类型 * @author dylan_xu * @date Mar 11, 2012 * @param aMask 指定的日期格式，如:yyyy-MM-dd * @param strDate 待转换的日期字符串 * @return * @throws ParseException */ public static final Date convertStringToDate(String aMask, String strDate) throws ParseException { SimpleDateFormat df = null; Date date = null; df = new SimpleDateFormat(aMask); if (logger.isDebugEnabled()) { logger.debug("converting '" + strDate + "' to date with mask '" + aMask + "'"); } try { date = df.parse(strDate); } catch (ParseException pe) { logger.error("ParseException: " + pe); throw pe; } return (date); } /** * 将日期字符串按默认格式转换成日期类型 * @author dylan_xu * @date Mar 11, 2012 * @param strDate * @return * @throws ParseException */ public static Date convertStringToDate(String strDate) throws ParseException { Date aDate = null; try { if (logger.isDebugEnabled()) { logger.debug("converting date with pattern: " + getDatePattern()); } aDate = convertStringToDate(getDatePattern(), strDate); } catch (ParseException pe) { logger.error("Could not convert '" + strDate + "' to a date, throwing exception"); throw new ParseException(pe.getMessage(), pe.getErrorOffset()); } return aDate; } /** * 返回一个JAVA简单类型的日期字符串 * @author dylan_xu * @date Mar 11, 2012 * @return */ public static String getSimpleDateFormat() { SimpleDateFormat formatter = new SimpleDateFormat(); String NDateTime = formatter.format(new Date()); return NDateTime; } /** * 将指定字符串格式的日期与当前时间比较 * @author DYLAN * @date Feb 17, 2012 * @param strDate 需要比较时间 * @return * <p> * int code * <ul> * <li>-1 当前时间 < 比较时间 </li> * <li> 0 当前时间 = 比较时间 </li> * <li>>=1当前时间 > 比较时间 </li> * </ul> * </p> */ public static int compareToCurTime (String strDate) { if (StringUtils.isBlank(strDate)) { return -1; } Date curTime = cale.getTime(); String strCurTime = null; try { strCurTime = sdf_datetime_format.format(curTime); } catch (Exception e) { if (logger.isDebugEnabled()) { logger.debug("[Could not format '" + strDate + "' to a date, throwing exception:" + e.getLocalizedMessage() + "]"); } } if (StringUtils.isNotBlank(strCurTime)) { return strCurTime.compareTo(strDate); } return -1; } /** * 为查询日期添加最小时间 * * @param 目标类型Date * @param 转换参数Date * @return */ @SuppressWarnings("deprecation") public static Date addStartTime(Date param) { Date date = param; try { date.setHours(0); date.setMinutes(0); date.setSeconds(0); return date; } catch (Exception ex) { return date; } } /** * 为查询日期添加最大时间 * * @param 目标类型Date * @param 转换参数Date * @return */ @SuppressWarnings("deprecation") public static Date addEndTime(Date param) { Date date = param; try { date.setHours(23); date.setMinutes(59); date.setSeconds(0); return date; } catch (Exception ex) { return date; } } /** * 返回系统现在年份中指定月份的天数 * * @param 月份month * @return 指定月的总天数 */ @SuppressWarnings("deprecation") public static String getMonthLastDay(int month) { Date date = new Date(); int[][] day = { { 0, 30, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } }; int year = date.getYear() + 1900; if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { return day[1][month] + ""; } else { return day[0][month] + ""; } } /** * 返回指定年份中指定月份的天数 * * @param 年份year * @param 月份month * @return 指定月的总天数 */ public static String getMonthLastDay(int year, int month) { int[][] day = { { 0, 30, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } }; if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { return day[1][month] + ""; } else { return day[0][month] + ""; } } /** * 判断是平年还是闰年 * @author dylan_xu * @date Mar 11, 2012 * @param year * @return */ public static boolean isLeapyear(int year) { if ((year % 4 == 0 && year % 100 != 0) || (year % 400) == 0) { return true; } else { return false; } } /** * 取得当前时间的日戳 * @author dylan_xu * @date Mar 11, 2012 * @return */ @SuppressWarnings("deprecation") public static String getTimestamp() { Date date = cale.getTime(); String timestamp = "" + (date.getYear() + 1900) + date.getMonth() + date.getDate() + date.getMinutes() + date.getSeconds() + date.getTime(); return timestamp; } /** * 取得指定时间的日戳 * * @return */ @SuppressWarnings("deprecation") public static String getTimestamp(Date date) { String timestamp = "" + (date.getYear() + 1900) + date.getMonth() + date.getDate() + date.getMinutes() + date.getSeconds() + date.getTime(); return timestamp; } public static void main(String[] args) { System.out.println(getYear() + "|" + getMonth() + "|" + getDate()); } } |
以上就是本文的全部内容，希望对大家的学习有所帮助。
