Date类
Date()：空参数结构，会以以后操作系统的工夫结构一个Date对象。
long getTime()：获取到从1970年开始，到这个Date对象示意的工夫，过了多少毫秒，返回工夫戳
public static void dateApi() { Date d1 = new Date(); System.out.println(d1); //Mon Jul 19 20:42:57 CST 2021 System.out.println(d1.getTime()); //1626698635074}Date日期类型的大小比拟
办法一：java.util.Date类实现了Comparable接口，能够间接调用Date的compareTo()办法来比拟大小
String beginTime = "2018-07-28 14:42:32";String endTime = "2018-07-29 12:26:32"; SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { Date date1 = format.parse(beginTime); Date date2 = format.parse(endTime); int compareTo = date1.compareTo(date2); System.out.println(compareTo); } catch (ParseException e) { e.printStackTrace();}compareTo()办法的返回值，date1小于date2返回-1，date1大于date2返回1，相等返回0
办法二：通过Date自带的before()或者after()办法比拟
String beginTime = "2018-07-28 14:42:32";String endTime = "2018-07-29 12:26:32"; SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { Date date1 = format.parse(beginTime); Date date2 = format.parse(endTime); boolean before = date1.before(date2); System.out.println(before); } catch (ParseException e) { e.printStackTrace();}before()或者after()办法的返回值为boolean类型
办法三：通过调用Date的getTime()办法获取到毫秒数来进行比拟
String beginTime = "2018-07-28 14:42:32";String endTime = "2018-07-29 12:26:32"; SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { Date date1 = format.parse(beginTime); Date date2 = format.parse(endTime); long beginMillisecond = date1.getTime(); long endMillisecond = date2.getTime(); System.out.println(beginMillisecond > endMillisecond); } catch (ParseException e) { e.printStackTrace();}Calendar类
Calendar提供了很不便的不同日期格局的解决
public static void main(String[] args) { System.out.println("------------Calendar无参结构------------"); //Calendar对象，不传参数，默认为以后日期 Calendar calendar =new GregorianCalendar(); //获取以后年份 System.out.println(calendar.get(Calendar.YEAR)); //获取以后月份 从0开始，0代表一月，1代表二月，以此类推 System.out.println(calendar.get(Calendar.MONTH)); //获取以后日期 也能够应用DAY_OF_MONTH System.out.println(calendar.get(Calendar.DATE)); //获取以后时 24小时进制 System.out.println(calendar.get(Calendar.HOUR_OF_DAY)); //获取以后分 System.out.println(calendar.get(Calendar.MINUTE)); //获取以后秒 System.out.println(calendar.get(Calendar.SECOND)); //获取明天是这个月的第几个星期 System.out.println(calendar.get(Calendar.WEEK_OF_MONTH)); //获取明天是星期几 1示意星期天，2示意星期一，以此类推 System.out.println(calendar.get(Calendar.DAY_OF_WEEK)); System.out.println("------------Calendar有参结构------------"); /** * 有参结构 别离代表年月日时分秒，写法简单明了，很合乎咱们人类的思维 * 留神月份的设置是从0开始的，这里设置的是月份是6，理论是设置了7月份 */ calendar =new GregorianCalendar(2019, 6, 14, 16, 15,30); /** * 除了在构造方法间接设置之外，也能够通过set办法设置 * 第一个参数示意设置的参数类型，第二个示意具体值 */ calendar.set(Calendar.YEAR, 2000); calendar.set(Calendar.MONTH, 0); calendar.set(Calendar.DATE, 20); //... System.out.println("------------Calendar和Date转换------------"); Date now = calendar.getTime(); calendar.setTime(now); System.out.println("------------Calendar日期计算以及判断------------"); calendar = new GregorianCalendar(); Calendar calendar2 = new GregorianCalendar(); calendar2.set(Calendar.YEAR, 2800); //是否在某个工夫(calendar2)之后 System.out.println(calendar.after(calendar2)); //是否在某个工夫(calendar2)之前 System.out.println(calendar.before(calendar2)); //减少多少年年，月日以及时分秒同理 calendar.add(Calendar.YEAR, -10);}Time类
java.time包中的是类是不可变且线程平安的。
●Instant——它代表的是工夫戳
●LocalDate——不蕴含具体工夫的日期，比方2014-01-14。它能够用来存储生日，周年纪念日，入职日期等。
●LocalTime——它代表的是不含日期的工夫
●LocalDateTime——它蕴含了日期及工夫，不过还是没有偏移信息或者说时区。
●ZonedDateTime——这是一个蕴含时区的残缺的日期工夫，偏移量是以UTC/格林威治工夫为基准的。
/**1.LocalDateTime相较于LocalDate、LocalTime，应用频率要高2.相似于Calendar*///now():获取以后的日期、工夫、日期+工夫LocalDate localDate = LocalDate.now(); //2021-02-04LocalTime localTime = LocalTime.now(); //10:11:34.741LocalDateTime localDateTime = LocalDateTime.now(); //2021-02-04T10:11:34.768//of():设置指定的年、月、日、时、分、秒。没有偏移量LocalDateTime localDateTime1 = LocalDateTime.of(2020, 10, 6, 13, 23, 43);System.out.println(localDateTime1); //2020-10-06T13:23:43//getXxx()：获取相干的属性System.out.println(localDateTime.getDayOfMonth()); //4 日期System.out.println(localDateTime.getDayOfWeek()); //THURSDAY 星期System.out.println(localDateTime.getMonth()); //FEBRUARY 月份 System.out.println(localDateTime.getMonthValue()); //2 月份System.out.println(localDateTime.getMinute()); //12 分//体现不可变性//withXxx():设置相干的属性LocalDate localDate1 = localDate.withDayOfMonth(22);System.out.println(localDate); //2021-02-04System.out.println(localDate1); //2021-02-22LocalDateTime localDateTime2 = localDateTime.withHour(4);System.out.println(localDateTime);System.out.println(localDateTime2);//不可变性LocalDateTime localDateTime3 = localDateTime.plusMonths(3);System.out.println(localDateTime);System.out.println(localDateTime3);LocalDateTime localDateTime4 = localDateTime.minusDays(6);System.out.println(localDateTime);System.out.println(localDateTime4);java.sql.Timestamp：工夫戳，适配于SQL中的TIMESTAMP类型而呈现的，准确到纳秒级别。
DateFormat 类 与 SimpleDateFormat类
DateFormat 类和 SimpleDateFormat 类来格式化日期
DateFormat 位于text包中，它是一个抽象类，不能被实例化
DateFormat类是SimpleDateFormat类父类
SimpleDateFormat 是一个以与语言环境无关的形式来格式化和解析日期的具体类。它容许进行格式化（日期 -> 文本）、解析（文本 -> 日期）和规范化。
应用样例
//工夫格式化DateFormat tf1 = DateFormat.getTimeInstance(DateFormat.FULL, Locale.CHINA);DateFormat tf2 = DateFormat.getTimeInstance(DateFormat.LONG, Locale.CHINA);DateFormat tf3 = DateFormat.getTimeInstance(DateFormat.MEDIUM, Locale.CHINA);DateFormat tf4 = DateFormat.getTimeInstance(DateFormat.SHORT, Locale.CHINA);String t1 = tf1.format(new Date());String t2 = tf2.format(new Date());String t3 = tf3.format(new Date());String t4 = tf4.format(new Date());// 日期格式化DateFormat df1 = DateFormat.getDateInstance(DateFormat.FULL, Locale.CHINA);DateFormat df2 = DateFormat.getDateInstance(DateFormat.LONG, Locale.CHINA);DateFormat df3 = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.CHINA);DateFormat df4 = DateFormat.getDateInstance(DateFormat.SHORT, Locale.CHINA);String d1 = df1.format(new Date());String d2 = df2.format(new Date());String d3 = df3.format(new Date());String d4 = df4.format(new Date());// 输入日期System.err.println( d1 + " |eguid| " + t1);System.err.println( d2 + " |eguid| " + t2);System.err.println( d3 + " |eguid| " + t3);System.err.println( d4 + " |eguid| " + t4);后果2018年10月15日 |eguid| 星期一 上午09时30分43秒 CST2018年10月15日 |eguid| 上午09时30分43秒2018-10-15 |eguid| 9:30:4318-10-15 |eguid| 上午9:30import java.text.SimpleDateFormat;import java.util.Date;/*** @auother eguid*/public class DateTest { public static void main(String[] args) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy 年 MM 月 dd 日 HH 点 mm 分 ss 秒"); System.err.println(sdf.format(new Date())); //格式化以后日期工夫 }}2018 年 10 月 15 日 09 点 26 分 23 秒DateFormatUtils类
//// Source code recreated from a .class file by IntelliJ IDEA// (powered by FernFlower decompiler)//package org.apache.commons.lang.time;import java.util.Calendar;import java.util.Date;import java.util.Locale;import java.util.TimeZone;public class DateFormatUtils { public static final FastDateFormat ISO_DATETIME_FORMAT = FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss"); public static final FastDateFormat ISO_DATETIME_TIME_ZONE_FORMAT = FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ssZZ"); public static final FastDateFormat ISO_DATE_FORMAT = FastDateFormat.getInstance("yyyy-MM-dd"); public static final FastDateFormat ISO_DATE_TIME_ZONE_FORMAT = FastDateFormat.getInstance("yyyy-MM-ddZZ"); public static final FastDateFormat ISO_TIME_FORMAT = FastDateFormat.getInstance("'T'HH:mm:ss"); public static final FastDateFormat ISO_TIME_TIME_ZONE_FORMAT = FastDateFormat.getInstance("'T'HH:mm:ssZZ"); public static final FastDateFormat ISO_TIME_NO_T_FORMAT = FastDateFormat.getInstance("HH:mm:ss"); public static final FastDateFormat ISO_TIME_NO_T_TIME_ZONE_FORMAT = FastDateFormat.getInstance("HH:mm:ssZZ"); public static final FastDateFormat SMTP_DATETIME_FORMAT; public DateFormatUtils() { } public static String formatUTC(long millis, String pattern) { return format((Date)(new Date(millis)), pattern, DateUtils.UTC_TIME_ZONE, (Locale)null); } public static String formatUTC(Date date, String pattern) { return format((Date)date, pattern, DateUtils.UTC_TIME_ZONE, (Locale)null); } public static String formatUTC(long millis, String pattern, Locale locale) { return format(new Date(millis), pattern, DateUtils.UTC_TIME_ZONE, locale); } public static String formatUTC(Date date, String pattern, Locale locale) { return format(date, pattern, DateUtils.UTC_TIME_ZONE, locale); } public static String format(long millis, String pattern) { return format((Date)(new Date(millis)), pattern, (TimeZone)null, (Locale)null); } public static String format(Date date, String pattern) { return format((Date)date, pattern, (TimeZone)null, (Locale)null); } public static String format(Calendar calendar, String pattern) { return format((Calendar)calendar, pattern, (TimeZone)null, (Locale)null); } public static String format(long millis, String pattern, TimeZone timeZone) { return format((Date)(new Date(millis)), pattern, timeZone, (Locale)null); } public static String format(Date date, String pattern, TimeZone timeZone) { return format((Date)date, pattern, timeZone, (Locale)null); } public static String format(Calendar calendar, String pattern, TimeZone timeZone) { return format((Calendar)calendar, pattern, timeZone, (Locale)null); } public static String format(long millis, String pattern, Locale locale) { return format((Date)(new Date(millis)), pattern, (TimeZone)null, locale); } public static String format(Date date, String pattern, Locale locale) { return format((Date)date, pattern, (TimeZone)null, locale); } public static String format(Calendar calendar, String pattern, Locale locale) { return format((Calendar)calendar, pattern, (TimeZone)null, locale); } public static String format(long millis, String pattern, TimeZone timeZone, Locale locale) { return format(new Date(millis), pattern, timeZone, locale); } public static String format(Date date, String pattern, TimeZone timeZone, Locale locale) { FastDateFormat df = FastDateFormat.getInstance(pattern, timeZone, locale); return df.format(date); } public static String format(Calendar calendar, String pattern, TimeZone timeZone, Locale locale) { FastDateFormat df = FastDateFormat.getInstance(pattern, timeZone, locale); return df.format(calendar); } static { SMTP_DATETIME_FORMAT = FastDateFormat.getInstance("EEE, dd MMM yyyy HH:mm:ss Z", Locale.US); }}DateUtils类
源码
package com.xinchacha.security.utils;import org.apache.commons.lang3.StringUtils;import org.apache.commons.lang3.time.DateFormatUtils;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.*;/** * @ClassName DateUtils * @Description TODO * @Author yiGeXinDong * @Date 2020/5/11 9:53 * @Version 1.0 **/public class DateUtils { public final static int FORMAT_DEFAULT = 0; // 默认格局 /** 日时字符串格局：长格局（如：年份用4位示意） */ public final static int FORMAT_LONG = 1; // 长格局（如：年份用4位示意） /** 日时字符串格局：短格局（如：年份用2位示意） */ public final static int FORMAT_SHORT = 2; // 短格局（如：年份用2位示意） /** 默认日期字符串格局 "yyyy-MM-dd" */ public final static String DATE_DEFAULT = "yyyy-MM-dd"; /** 日期字符串格局 "yyyy" */ private final static String DATE_YYYY="yyyy"; /** 日期字符串格局 "mm" */ private final static String DATE_MM="mm"; /** 日期字符串格局 "dd" */ private final static String DATE_DD="dd"; /** 日期字符串格局 "yyyyMM" */ public final static String DATE_YYYYMM = "yyyyMM"; /** 日期字符串格局 "yyyyMMdd" */ public final static String DATE_YYYYMMDD = "yyyyMMdd"; /** 日期字符串格局 "yyyy-MM" */ public final static String DATE_YYYY_MM = "yyyy-MM"; /** 日期字符串格局 "yyyy-MM-dd" */ public final static String DATE_YYYY_MM_DD = "yyyy-MM-dd"; /** 默认日时字符串格局 "yyyy-MM-dd HH:mm:ss" */ public final static String DATETIME_DEFAULT = "yyyy-MM-dd HH:mm:ss"; /** 日时字符串格局 "yyyy-MM-dd HH:mm" */ public final static String DATETIME_YYYY_MM_DD_HH_MM = "yyyy-MM-dd HH:mm"; /** 日时字符串格局 "yyyy-MM-dd HH:mm:ss" */ public final static String DATETIME_YYYY_MM_DD_HH_MM_SS = "yyyy-MM-dd HH:mm:ss"; /** 日时字符串格局 "yyyy-MM-dd HH:mm:ss.SSS" */ public final static String DATETIME_YYYY_MM_DD_HH_MM_SS_SSS = "yyyy-MM-dd HH:mm:ss.SSS"; /** 默认工夫字符串格局 "HH:mm:ss" */ public final static String TIME_DEFAULT = "HH:mm:ss"; /** 默认工夫字符串格局 "HH:mm" */ public final static String TIME_HH_MM = "HH:mm"; /** 默认工夫字符串格局 "HH:mm:ss" */ public final static String TIME_HH_MM_SS = "HH:mm:ss"; public static final long YEAR_NUMBER=365; /** 分 */ public static final long MINUTE_TTL = 60 * 1000l; /** 时 */ public static final long HOURS_TTL = 60 * 60 * 1000l; /** 半天 */ public static final long HALF_DAY_TTL = 12 * 60 * 60 * 1000l; /** 天 */ public static final long DAY_TTL = 24 * 60 * 60 * 1000l; /** 月 */ public static final long MONTH_TTL = 30 * 24 * 60 * 60 * 1000l; /** * TODO 计算两个工夫差值 * @param startDate,endDate * @Author XuWenXiao * @return int(两个工夫相差的天数) * @throws ParseException */ public static int daysBetween(Date startDate, Date endDate) throws ParseException { Calendar calendar = Calendar.getInstance(); calendar.setTime(startDate); long sTime = calendar.getTimeInMillis(); calendar.setTime(endDate); long endTime = calendar.getTimeInMillis(); long between_days=(endTime-sTime)/DAY_TTL; return Integer.parseInt(String.valueOf(between_days)); } /** * TODO 获取以后零碎工夫 * @Author XuWenXiao * @return Date */ public static Date getNewDate(){ SimpleDateFormat df = new SimpleDateFormat(DATETIME_YYYY_MM_DD_HH_MM_SS);//设置日期格局 Date newDate=null; try { newDate=df.parse(df.format(new Date())); } catch (ParseException e) { e.printStackTrace(); } return newDate; } /** * 失去日期字符串 默认格局（yyyy-MM-dd） pattern能够为："yyyy-MM-dd" "HH:mm:ss" "E" */ public static String formatDate(Date date, Object... pattern) { String formatDate = null; if (pattern != null && pattern.length > 0) { formatDate = DateFormatUtils.format(date, pattern[0].toString()); } else { formatDate = DateFormatUtils.format(date, DATE_YYYY_MM_DD); } return formatDate; } /** * 失去以后年份字符串 格局（yyyy） */ public static String getYear() { return formatDate(new Date(), DATE_YYYY); } /** * 失去以后月份字符串 格局（MM） */ public static String getMonth() { return formatDate(new Date(), DATE_MM); } /** * 失去当天字符串 格局（dd） */ public static String getDay() { return formatDate(new Date(), DATE_DD); } /** * 获取以后工夫的字符串模式（例如；"201806291135"） * @return 年月日时分 */ public static String getDateToString(){ Calendar c = Calendar.getInstance(); return getYear()+getMonth()+getDay()+c.get(Calendar.HOUR_OF_DAY)+c.get(Calendar.MINUTE); } /** * 获取过来的年数 * @param date * @return */ public static Long pastYear(Date date) { return date==null?null:pastDays(date)/YEAR_NUMBER; } /** * 获取过来的天数 * @param date * @return */ public static long pastDays(Date date) { long t = new Date().getTime()-date.getTime(); return t/DAY_TTL; } /** * 获取过来的小时 * @param date * @return */ public static long pastHour(Date date) { long t = new Date().getTime()-date.getTime(); return t/HOURS_TTL; } /** * 获取过来的分钟 * @param date * @return */ public static long pastMinutes(Date date) { long t = new Date().getTime()-date.getTime(); return t/MINUTE_TTL; } /** * 获取两个日期之间的天数 * * @param before * @param after * @return */ public static double getDistanceOfTwoDate(Date before, Date after) { long beforeTime = before.getTime(); long afterTime = after.getTime(); return (afterTime - beforeTime) /DAY_TTL; } /** * 依据身份证计算出身日期 * */ /** * 通过身份证号码获取出生日期、性别、年齡 * @param certificateNo * @return 返回的出生日期格局：1990-01-01 性别格局：2-女，1-男 */ public static Map<String, String> getBirAgeSex(String certificateNo) { System.out.println(certificateNo); String birthday = ""; String age = ""; String sexCode = ""; int year = Calendar.getInstance().get(Calendar.YEAR); char[] number = certificateNo.toCharArray(); boolean flag = true; if (number.length == 15) { for (int x = 0; x < number.length; x++) { if (!flag) return new HashMap<String, String>(); flag = Character.isDigit(number[x]); } } else if (number.length == 18) { for (int x = 0; x < number.length - 1; x++) { if (!flag) return new HashMap<String, String>(); flag = Character.isDigit(number[x]); } } if (flag && certificateNo.length() == 15) { birthday = "19" + certificateNo.substring(6, 8) + "-" + certificateNo.substring(8, 10) + "-" + certificateNo.substring(10, 12); sexCode = Integer.parseInt(certificateNo.substring(certificateNo.length() - 3, certificateNo.length())) % 2 == 0 ? "2" : "1"; age = (year - Integer.parseInt("19" + certificateNo.substring(6, 8))) + ""; } else { birthday = certificateNo.substring(6, 10) + "-" + certificateNo.substring(10, 12) + "-" + certificateNo.substring(12, 14); sexCode = Integer.parseInt(certificateNo.substring(certificateNo.length() - 4, certificateNo.length() - 1)) % 2 == 0 ? "2" : "1"; age = (year - Integer.parseInt(certificateNo.substring(6, 10))) + ""; } Map<String, String> map = new HashMap<String, String>(); map.put("birthday", birthday); map.put("age", age); map.put("sexCode", sexCode); return map; } /** * 依据身份证的号码算出以后身份证持有者的年龄 18位身份证 * @author 黄涛 * @return * @throws Exception */ public static int getCarAge(String birthday){ String year = birthday.substring(0, 4);//失去年份 String yue = birthday.substring(4, 6);//失去月份 //String day = birthday.substring(6, 8);// Date date = new Date();// 失去以后的零碎工夫 SimpleDateFormat format = new SimpleDateFormat(DATE_YYYY_MM_DD); String fYear = format.format(date).substring(0, 4);// 以后年份 String fYue = format.format(date).substring(5, 7);// 月份 // String fday=format.format(date).substring(8,10); int age = 0; if (Integer.parseInt(yue) <= Integer.parseInt(fYue)) { // 以后月份大于用户出身的月份示意已过生 age = Integer.parseInt(fYear) - Integer.parseInt(year) + 1; } else {// 以后用户还没过生 age = Integer.parseInt(fYear) - Integer.parseInt(year); } return age; } /** * * 依据身份证获取性别 */ public static String getCarSex(String CardCode){ String sex; if (Integer.parseInt(CardCode.substring(16).substring(0, 1)) % 2 == 0) {// 判断性别 sex = "2"; } else { sex = "1"; } return sex; } /** * 依据传入的日历型日期，计算出执行的工夫值（准确版） * @param beginTime * @param endTime * @return */ public static String countExecTimeToString_exact(Calendar beginTime,Calendar endTime) {//计算两个日期类型之间的差值（单位：毫秒） Long timeDispersion = endTime.getTimeInMillis() - beginTime.getTimeInMillis(); String tmpMsg = "耗时: ";//拼写输入的字符串 int timeNum = 0;//记录时间的数值（几小时、几分、几秒） if(timeDispersion >= (HOURS_TTL))//判断是否足够一小时 {//若足够则计算有几小时 timeNum = (int) (timeDispersion/HOURS_TTL); tmpMsg += timeNum + "时";//拼写输入几小时 timeDispersion = timeDispersion - (timeNum*HOURS_TTL);//减去小时数（这样剩下的就是分钟数了） } if(timeDispersion >= (MINUTE_TTL))//判断是否足够一分钟 {//若足够则计算有几分钟 timeNum = (int) (timeDispersion/MINUTE_TTL); tmpMsg += timeNum + "分";//拼写输入几分钟 timeDispersion = timeDispersion - (timeNum*MINUTE_TTL);//减去分钟数（这样就剩下秒数了） } if(timeDispersion >= 1000)//判断是否足够一秒 {//若足够则计算几秒 timeNum = (int) (timeDispersion/1000); tmpMsg += timeNum + "秒";//拼写输入秒数 timeDispersion = timeDispersion - timeNum*1000;//减去秒数（这样就剩下毫秒数了） } tmpMsg += timeDispersion + "毫秒";//拼写输入毫秒数 return tmpMsg; }//重载办法，返回Long类型（毫秒） public static Long countExecTimeToLong_exact(Calendar beginTime,Calendar endTime) {//间接返回毫秒数 return (endTime.getTimeInMillis() - beginTime.getTimeInMillis()); } /** * 依据传入的long类型日期，计算出执行的工夫值（准确版） * @param beginTime * @param endTime * @return */ public static String countExecTimeToString_exact(Long beginTime,Long endTime) {//计算两个日期类型之间的差值（单位：毫秒） Long timeDispersion = endTime - beginTime; String tmpMsg = "耗时: ";//拼写输入的字符串 int timeNum = 0;//记录时间的数值（几小时、几分、几秒） if(timeDispersion >= (HOURS_TTL))//判断是否足够一小时 {//若足够则计算有几小时 timeNum = (int) (timeDispersion/(HOURS_TTL)); tmpMsg += timeNum + "时";//拼写输入几小时 timeDispersion = timeDispersion - (timeNum*HOURS_TTL);//减去小时数（这样剩下的就是分钟数了） } if(timeDispersion >= (MINUTE_TTL))//判断是否足够一分钟 {//若足够则计算有几分钟 timeNum = (int) (timeDispersion/(MINUTE_TTL)); tmpMsg += timeNum + "分";//拼写输入几分钟 timeDispersion = timeDispersion - (timeNum*MINUTE_TTL);//减去分钟数（这样就剩下秒数了） } if(timeDispersion >= 1000)//判断是否足够一秒 {//若足够则计算几秒 timeNum = (int) (timeDispersion/1000); tmpMsg += timeNum + "秒";//拼写输入秒数 timeDispersion = timeDispersion - timeNum*1000;//减去秒数（这样就剩下毫秒数了） } tmpMsg += timeDispersion + "毫秒";//拼写输入毫秒数 return tmpMsg; } /** * 获取指定年度全副月份汇合<br> * 格局为yyyy-MM * @author 王鹏 * @version 2019年11月16日 下午4:52:55 * @param year 年度 * @return */ public static List<String> getYearMonthByYear(String year) { List<String> monthList =new ArrayList<>(); for (int i = 1; i <= 12; i++) { monthList.add(year+"-"+(i<10?"0":"")+i); } return monthList; } /** * 获取下个月 * dateStr 日期 * format 格局：yyyy-MM或yyyyMM * @return */ public static String getPreMonth(String dateStr,String format) { String preMonth = ""; SimpleDateFormat sdf = new SimpleDateFormat(format); Date date; try { date = sdf.parse(dateStr); Calendar calendar = Calendar.getInstance(); calendar.setTime(date); calendar.add(calendar.MONTH, 1); sdf.format(calendar.getTime()); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return preMonth; } /** * 获取下个月 * dateStr 日期 * format 格局：yyyy-MM或yyyyMM * @return */ public static String getPreMonthFormat(String dateStr,String format) { String preMonth = ""; SimpleDateFormat sdf = new SimpleDateFormat(format); Date date; try { date = sdf.parse(dateStr); Calendar calendar = Calendar.getInstance(); calendar.setTime(date); calendar.add(calendar.MONTH, 1); preMonth= sdf.format(calendar.getTime()); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return preMonth; } /** * 日期比拟 * date1比date2大true */ public static boolean dateSize(String aDate,String bDate,SimpleDateFormat format) { boolean str = false; try { if(StringUtils.isNotBlank(aDate)&&StringUtils.isNotBlank(bDate)) { Date date1 = format.parse(aDate); Date date2 = format.parse(bDate); str = date1.after(date2); } } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return str; }}自定义DateUtil类
package com.jd.survey.common.utils;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import org.apache.commons.lang3.StringUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;public class DateUtil { private static final Logger log = LoggerFactory.getLogger(DateUtil.class); private static final String default_format = "yyyy-MM-dd HH:mm:ss"; private static final String format_yyyy = "yyyy"; private static final String format_yyyyMM = "yyyy-MM"; private static final String format_yyyyMMdd = "yyyy-MM-dd"; private static final String format_yyyyMMddHH = "yyyy-MM-dd HH"; private static final String format_yyyyMMddHHmm = "yyyy-MM-dd HH:mm"; private static final String format_yyyyMMddHHmmss = "yyyy-MM-dd HH:mm:ss"; public static final int MONDAY = 1; public static final int TUESDAY = 2; public static final int WEDNESDAY = 3; public static final int THURSDAY = 4; public static final int FRIDAY = 5; public static final int SATURDAY = 6; public static final int SUNDAY = 7; public static final int JANUARY = 1; public static final int FEBRUARY = 2; public static final int MARCH = 3; public static final int APRIL = 4; public static final int MAY = 5; public static final int JUNE = 6; public static final int JULY = 7; public static final int AUGUST = 8; public static final int SEPTEMBER = 9; public static final int OCTOBER = 10; public static final int NOVEMBER = 11; public static final int DECEMBER = 12; public static final Date parseDate(String strDate, String format) { SimpleDateFormat df = null; Date date = null; df = new SimpleDateFormat(format); try { date = df.parse(strDate); } catch (ParseException e) {} return (date); } public static Date now() { return new Date(); } public static int getYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(1); } public static int getDayOfMonth(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(5); } public static int getMonthOfYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(2) + 1; } public static int getDayOfWeek(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.setFirstDayOfWeek(2); int day = calendar.get(7) - 1; if (day == 0) { day = 7; } return day; } public static Date getTodayEndTime(){ Calendar calendar = Calendar.getInstance(); calendar.setTime(new Date()); calendar.set(Calendar.HOUR_OF_DAY,23); calendar.set(Calendar.MINUTE,59); calendar.set(Calendar.SECOND,59); return calendar.getTime(); } public static int getDayOfYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(6); } public static int getHourField(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(11); } public static int getMinuteField(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(12); } public static int getSecondField(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(13); } public static int getMillisecondField(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.get(14); } public static long getDays(Date datetime) { return datetime.getTime() / 86400000L; } public static long getHours(Date datetime) { return datetime.getTime() / 3600000L; } public static long getMinutes(Date datetime) { return datetime.getTime() / 60000L; } public static long getSeconds(Date datetime) { return datetime.getTime() / 1000L; } public static long getMilliseconds(Date datetime) { return datetime.getTime(); } public static int getWeekOfMonth(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.setFirstDayOfWeek(2); return calendar.get(4); } public static int getWeekOfYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.setFirstDayOfWeek(2); return calendar.get(3); } public static int getMaxDateOfMonth(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.getActualMaximum(5); } public static int getMaxDateOfYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); return calendar.getActualMaximum(6); } public static int getMaxWeekOfMonth(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.setFirstDayOfWeek(2); return calendar.getActualMaximum(4); } public static int getMaxWeekOfYear(Date datetime) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.setFirstDayOfWeek(2); return calendar.getActualMaximum(3); } public static Date toDatetime(String datetimeString, String format) { Date result = null; try { SimpleDateFormat simpleDateFormat = new SimpleDateFormat(format); result = simpleDateFormat.parse(datetimeString); } catch (Exception e) { log.error("Fail to parse datetime.", e); } return result; } public static String toString(Date datetime) { return toString(datetime, null); } public static String toString(Date datetime, String format) { String result = null; SimpleDateFormat simpleDateFormat = null; try { if (StringUtils.isNoneBlank(new CharSequence[] { format })) { simpleDateFormat = new SimpleDateFormat(format); } else { simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); } result = simpleDateFormat.format(datetime); } catch (Exception e) { log.error("Fail to parse datetime.", e); } return result; } public static int diffYears(Date datetime1, Date datetime2) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime1); int month1 = calendar.get(1); calendar.setTime(datetime2); int month2 = calendar.get(1); return month1 - month2; } public static int diffMonths(Date datetime1, Date datetime2) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime1); int month1 = calendar.get(2); calendar.setTime(datetime2); int month2 = calendar.get(2); return month1 - month2; } public static long diffDays(Date datetime1, Date datetime2) { return (datetime1.getTime() - datetime2.getTime()) / 86400000L; } public static long diffDaysByCalendar(Date datetime1, Date datetime2) throws Exception { try { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); return diffDays(sdf.parse(sdf.format(datetime1)), sdf.parse(sdf.format(datetime2))); } catch (Exception e) { throw e; } } public static long diffHours(Date datetime1, Date datetime2) { return (datetime1.getTime() - datetime2.getTime()) / 3600000L; } public static long diffMiniutes(Date datetime1, Date datetime2) { return (datetime1.getTime() - datetime2.getTime()) / 60000L; } public static long diffSeconds(Date datetime1, Date datetime2) { return (datetime1.getTime() - datetime2.getTime()) / 1000L; } public static Date add(Date datetime1, Date datetime2) { Calendar calendar = Calendar.getInstance(); Date date = new Date(datetime1.getTime() + datetime2.getTime()); return date; } public static Date minus(Date datetime1, Date datetime2) { Calendar calendar = Calendar.getInstance(); Date date = new Date(datetime1.getTime() - datetime2.getTime()); return date; } public static boolean isBefore(Date datetime1, Date datetime2) { return datetime2.getTime() - datetime1.getTime() > 0L; } public static boolean isBeforeOrEqual(Date datetime1, Date datetime2) { return datetime2.getTime() - datetime1.getTime() >= 0L; } public static boolean isEqual(Date datetime1, Date datetime2) { return datetime2.getTime() == datetime1.getTime(); } public static boolean isAfter(Date datetime1, Date datetime2) { return datetime2.getTime() - datetime1.getTime() < 0L; } public static boolean isAfterOrEqual(Date datetime1, Date datetime2) { return datetime2.getTime() - datetime1.getTime() <= 0L; } public static Date addMilliseconds(Date datetime, int milliseconds) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(14, milliseconds); return calendar.getTime(); } public static Date addSeconds(Date datetime, int seconds) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(13, seconds); return calendar.getTime(); } public static Date addMinutes(Date datetime, int minutes) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(12, minutes); return calendar.getTime(); } public static Date addHours(Date datetime, int hours) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(10, hours); return calendar.getTime(); } public static Date addDays(Date datetime, int days) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(5, days); return calendar.getTime(); } public static Date addMonths(Date datetime, int months) { Calendar calendar = Calendar.getInstance(); calendar.setTime(datetime); calendar.roll(2, months); return calendar.getTime(); } public static boolean isSameSecond(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameMinute(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameHour(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameDay(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameMonth(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameYear(Date datetime1, Date datetime2) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy"); return sdf.format(datetime1).equals(sdf.format(datetime2)); } public static boolean isSameWeek(Date datetime1, Date datetime2) { boolean result = false; int year1 = getYear(datetime1); int year2 = getYear(datetime2); int month1 = getMonthOfYear(datetime1); int month2 = getMonthOfYear(datetime2); int dayOfWeek1 = getDayOfWeek(datetime1); int dayOfWeek2 = getDayOfWeek(datetime2); long diffDays = diffDays(datetime1, datetime2); Calendar calendar = Calendar.getInstance(); calendar.setFirstDayOfWeek(2); if (Math.abs(diffDays) < calendar.getMaximum(7)) { if (year1 == year2) { if (getWeekOfYear(datetime1) == getWeekOfYear(datetime2)) { result = true; } } else if ((year1 - year2 == 1) && (month1 == 1) && (month2 == 12)) { calendar.set(year1, 0, 1); int dayOfWeek = getDayOfWeek(calendar.getTime()); if ((dayOfWeek2 < dayOfWeek) && (dayOfWeek <= dayOfWeek1)) { result = true; } } else if ((year2 - year1 == 1) && (month1 == 12) && (month2 == 1)) { calendar.set(year2, 0, 1); int dayOfWeek = getDayOfWeek(calendar.getTime()); if ((dayOfWeek1 < dayOfWeek) && (dayOfWeek <= dayOfWeek2)) { result = true; } } } return result; }}参考资料
Java中罕用的Date类型
https://blog.csdn.net/qiuwenjie123/article/details/79846621
Calendar类简介
https://blog.csdn.net/qq_42815754/article/details/95896544
java中time的工夫类
https://blog.csdn.net/ppppppushcar/article/details/113704597
Java日期格式化：DateFormat类和SimpleDateFormat类详解
https://blog.csdn.net/eguid/article/details/116054105