硬核！万人围观，Java时间工具类，无法拒绝

一时失言乱红尘 2022-10-13 05:21 64阅读 0赞

### 第一种： 日历工具类 ###

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package com.baidu.base.util;
    
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    /**
     *
     * @Title: CalendarUtil
     * @Description: 日历工具类
     */
    public class CalendarUtil {
    
        /**
         * 
         * @Description 获得指定日期工作周的指定星期几的日期
         * @Title getDateByWeekToDate
         * @param date
         * @param week
         * @return
         */
        public static Date getDateByWeekToDate(Date date, int week) {
            if (week <= 0) {
                return date;
            }
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.set(Calendar.DAY_OF_WEEK, week);
            calendar.set(Calendar.HOUR_OF_DAY, 23);
            calendar.set(Calendar.MINUTE, 59);
            calendar.set(Calendar.SECOND, 59);
            return calendar.getTime();
        }
        /**
         * @Description 得到按当前日期往前推一个月格式化时间格式为 00:00:00
         * @Title getUpperMonthTheToDay
         * @param date
         * @return
         */
        public static Date getUpperMonthTheToDayHHMMSS(Date date) {
            Calendar c = Calendar.getInstance();
            c.setTime(date);
            c.add(Calendar.MONTH, -1);
            c.add(Calendar.DAY_OF_MONTH, 1);
            c.set(Calendar.HOUR_OF_DAY, 00);
            c.set(Calendar.MINUTE, 00);
            c.set(Calendar.SECOND, 00);
            return c.getTime();
        }
        /**
         * 
         * @Description 获得指定日期的最初时间 最初时间为00:00:00
         * @Title getDayBegin
         * @param date
         * @return
         */
        public static Date getDayBegin(Date date) {
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.set(Calendar.HOUR_OF_DAY, 0);
            calendar.set(Calendar.MINUTE, 0);
            calendar.set(Calendar.SECOND, 0);
            return calendar.getTime();
        }
    
        /**
         * @Description 获得指定日期的最终时间 最终时间为23:59:59
         * @Title getDayEnd
         * @param date
         * @return
         */
        public static Date getDayEnd(Date date) {
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.set(Calendar.HOUR_OF_DAY, 23);
            calendar.set(Calendar.MINUTE, 59);
            calendar.set(Calendar.SECOND, 59);
            return calendar.getTime();
        }
    
        /**
         * 
         * @Description 得到指定日期的天数范围， day可以为正/负数，正数为向后推day天，负数为向前推day天，不含当天
         * @Title getDateByDayToDate
         * @param date
         * @param day
         * @return
         */
        public static Date getDateByDayToDate(Date date, int day) {
            if (day == 0) {
                return date;
            }
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.add(Calendar.DAY_OF_MONTH, day);
            return calendar.getTime();
        }
    
        /**
         *
         * @Description 获得本周的第一天，周一
         * @Title getWeekDayStartTime
         * @param date
         * @return
         */
        public static Date getWeekDayStartTime(Date date) {
            Calendar c = Calendar.getInstance();
            c.setTime(date);
            c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);//设置周一
            c.set(Calendar.HOUR_OF_DAY, 0);
            c.set(Calendar.MINUTE, 0);
            c.set(Calendar.SECOND, 0);
    //        c.setFirstDayOfWeek(Calendar.MONDAY);
            return c.getTime();
    
        }
    
        /**
         * @Description 获得本周的最后一天，周日
         * @Title getWeekDayEndTime
         * @param date
         * @return
         */
        public static Date getWeekDayEndTime(Date date) {
            Calendar c = Calendar.getInstance();
            c.setTime(date);
            c.setFirstDayOfWeek(Calendar.MONDAY);
            c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6);
            c.set(Calendar.HOUR_OF_DAY, 23);
            c.set(Calendar.MINUTE, 59);
            c.set(Calendar.SECOND, 59);
            return c.getTime();
        }
        
        /**
         * @Description 得到指定年月的第一天
         * @Title getStartDayByYearMonth
         * @param year
         * @param month
         * @return
         */
        public static Date getBeginDayByYearMonth(int year, int month) {
        	Calendar c = Calendar.getInstance();
        	c.clear();
        	c.set(year, month-1, 1);
        	return getDayBegin(c.getTime());
        }
        
        /**
         * @Description 得到指定年月的最后一天
         * @Title getEndDayByYearMonth
         * @param year
         * @param month
         * @return
         */
        public static Date getEndDayByYearMonth(int year, int month) {
        	Calendar c = Calendar.getInstance();
        	c.clear();
        	c.set(year, month-1, 1);
        	int endDay = c.getActualMaximum(Calendar.DAY_OF_MONTH);
        	c.set(Calendar.DAY_OF_MONTH, endDay);
        	return getDayEnd(c.getTime());
        }
        
        /**
         * @Description 得到按当前日期往前推一个月
         * @Title getUpperMonthTheToDay
         * @param date
         * @return
         */
        public static Date getUpperMonthTheToDay(Date date) {
            Calendar c = Calendar.getInstance();
            c.setTime(date);
            c.add(Calendar.MONTH, -1);
            c.add(Calendar.DAY_OF_MONTH, 1);
            return c.getTime();
        }
        
        /**
         * 
         * @Description 得到一年的第一天
         * @Title getStartYear
         * @param year
         * @return
         */
        public static Date getBeginYear(int year) {
        	Calendar c = Calendar.getInstance();
        	c.set(year, 0, 1, 0, 0, 0);
        	return c.getTime();
        }
        
        /**
         * @Description 得到一年的最后一天
         * @Title getEndYear
         * @param year
         * @return
         */
        public static Date getEndYear(int year) {
        	Date date = getBeginYear(year);
        	Calendar c = Calendar.getInstance();
        	c.setTime(date);
        	c.add(Calendar.YEAR, 1);
        	c.set(Calendar.SECOND, -1);
        	return c.getTime();
        }
        
        /**
         * @Description 得到当前时间的年份
         * @Title getYear
         * @param date
         * @return
         */
        public static int getYear(Date date) {
        	Calendar c = Calendar.getInstance();
        	c.setTime(date);
        	return c.get(Calendar.YEAR);
        }
        
        /**
         * @Description 得到当前时间的月份
         * @Title getMonth
         * @param date
         * @return
         */
        public static int getMonth(Date date) {
        	Calendar c = Calendar.getInstance();
        	c.setTime(date);
        	return c.get(Calendar.MONTH) + 1;
        }
        
        /**
         * 
         * @Description 得到date的差别日期  
         * @Title getDifferenceDay
         * @param date 日期
         * @param day 差别天数，可以为正，可以为-
         * @return
         */
        public static Date getDifferenceDay(Date date, int day) {
        	Calendar c = Calendar.getInstance();
        	c.setTime(date);
        	c.add(Calendar.DAY_OF_MONTH, day);
        	return c.getTime();
        }
    
        
        public static void main(String[] arge) throws Exception {
        	SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        	Date date = getDifferenceDay(new Date(), -1);
        	
        	System.out.println(sdf.format(date));
        }
    }

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### 第二种：日期处理类 ###

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package com.baidu.base.util;
    
    import java.text.DateFormat;
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    /**
     *
     * @Title: DateUtil
     * @Description: 日期处理w
     */
    public class DateUtil {
    	
    	private final static SimpleDateFormat sdfYear = new SimpleDateFormat("yyyy");
    	private final static SimpleDateFormat sdfDay = new SimpleDateFormat("yyyy-MM-dd");
    	private final static SimpleDateFormat sdfDays = new SimpleDateFormat("yyyyMMdd");
    	private final static SimpleDateFormat sdfTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    	private final static SimpleDateFormat sdfTimes = new SimpleDateFormat("yyyyMMddHHmmss");
    	 /**
         * 标准的日期时间字符串格式
         */
        public static final String STANDARD_DATETIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    	
        /**
         * 标准的日期字符串格式
         */
        public static final String STANDARD_DATE_FORMAT = "yyyy-MM-dd";
        /**
    	 * 获取YYYY格式
    	 * @return
    	 */
    	public static String getSdfTimes() {
    		return sdfTimes.format(new Date());
    	}
    	
    	/**
    	 * 获取YYYY格式
    	 * @return
    	 */
    	public static String getYear() {
    		return sdfYear.format(new Date());
    	}
    
    	/**
    	 * 获取YYYY-MM-DD格式
    	 * @return
    	 */
    	public static String getDay() {
    		return sdfDay.format(new Date());
    	}
    	
    	/**
    	 * 获取YYYYMMDD格式
    	 * @return
    	 */
    	public static String getDays(){
    		return sdfDays.format(new Date());
    	}
    
    	/**
    	 * 获取YYYY-MM-DD HH:mm:ss格式
    	 * @return
    	 */
    	public static String getTime() {
    		return sdfTime.format(new Date());
    	}
    
    	/**
    	* @Title: compareDate
    	* @Description: TODO(日期比较，如果s>=e 返回true 否则返回false)
    	* @param s
    	* @param e
    	* @return boolean  
    	* @throws
    	* @author fh
    	 */
    	public static boolean compareDate(String s, String e) {
    		if(fomatDate(s)==null||fomatDate(e)==null){
    			return false;
    		}
    		return fomatDate(s).getTime() >=fomatDate(e).getTime();
    	}
    
    	/**
    	 * 格式化日期
    	 * @return
    	 */
    	public static Date fomatDate(String date) {
    		DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
    		try {
    			return fmt.parse(date);
    		} catch (ParseException e) {
    			e.printStackTrace();
    			return null;
    		}
    	}
    
    	/**
    	 * 校验日期是否合法
    	 * @return
    	 */
    	public static boolean isValidDate(String s) {
    		DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
    		try {
    			fmt.parse(s);
    			return true;
    		} catch (Exception e) {
    			// 如果throw java.text.ParseException或者NullPointerException，就说明格式不对
    			return false;
    		}
    	}
    	
    	/**
    	 * @param startTime
    	 * @param endTime
    	 * @return
    	 */
    	public static int getDiffYear(String startTime,String endTime) {
    		DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
    		try {
    			//long aa=0;
    			int years=(int) (((fmt.parse(endTime).getTime()-fmt.parse(startTime).getTime())/ (1000 * 60 * 60 * 24))/365);
    			return years;
    		} catch (Exception e) {
    			// 如果throw java.text.ParseException或者NullPointerException，就说明格式不对
    			return 0;
    		}
    	}
    	 
    	/**
         * <li>功能描述：时间相减得到天数
         * @param beginDateStr
         * @param endDateStr
         * @return
         * long 
         * @author Administrator
         */
        public static long getDaySub(String beginDateStr,String endDateStr){
            long day=0;
            java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd");
            java.util.Date beginDate = null;
            java.util.Date endDate = null;
            
                try {
    				beginDate = format.parse(beginDateStr);
    				endDate= format.parse(endDateStr);
    			} catch (ParseException e) {
    				e.printStackTrace();
    			}
                day=(endDate.getTime()-beginDate.getTime())/(24*60*60*1000);
                //System.out.println("相隔的天数="+day);
          
            return day;
        }
        
        /**
         * 得到n天之后的日期
         * @param days
         * @return
         */
        public static String getAfterDayDate(String days) {
        	int daysInt = Integer.parseInt(days);
        	
            Calendar canlendar = Calendar.getInstance(); // java.util包
            canlendar.add(Calendar.DATE, daysInt); // 日期减 如果不够减会将月变动
            Date date = canlendar.getTime();
            
            SimpleDateFormat sdfd = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String dateStr = sdfd.format(date);
            
            return dateStr;
        }
        
        /**
         * 得到n天之后是周几
         * @param days
         * @return
         */
        public static String getAfterDayWeek(String days) {
        	int daysInt = Integer.parseInt(days);
            Calendar canlendar = Calendar.getInstance(); // java.util包
            canlendar.add(Calendar.DATE, daysInt); // 日期减 如果不够减会将月变动
            Date date = canlendar.getTime();
            SimpleDateFormat sdf = new SimpleDateFormat("E");
            String dateStr = sdf.format(date);
            return dateStr;
        }
        
        
        /**
         * 获取当前时间
         *
         * @return Date
         */
        public static Date getCurrentTime() {
        	SimpleDateFormat format = new SimpleDateFormat(STANDARD_DATE_FORMAT);
            try {
    			return format.parse(format.format(new Date()));
    		} catch (ParseException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
            return new Date();
        }
        
        /**
         * 获取当前时间     yyyy-MM-dd HH:mm:ss格式
         *
         * @return Date
         */
        public static Date getCurrentTimes() {
        	SimpleDateFormat format = new SimpleDateFormat(STANDARD_DATETIME_FORMAT);
            try {
    			return format.parse(format.format(new Date()));
    		} catch (ParseException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
            return new Date();
        }
        
        public static Date convertStringToDate(String dateString, String format) {
    
            SimpleDateFormat dateFormat = new SimpleDateFormat(format);
            Date date = null;
    
            try {
                date = dateFormat.parse(dateString);
            } catch (ParseException e) {
                // do nothing
            }
    
            return date;
        }
        
        /**
         * 对日期对象进行天数加减
         *
         * @param date 日期对象
         * @param days 天数,如果要将日期向前推算则使用负数
         * @return Date
         */
        public static Date addDays(Date date, int days) {
    
            Date newDate = new Date(date.getTime() + (long) days * 24 * 60 * 60 * 1000);
            return newDate;
        }
        public static void main(String[] args) {
        	System.out.println(getDays());
        	System.out.println(getAfterDayWeek("3"));
        }
    
    }

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