时间处理工具类

package com.skjd.util;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

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 sdfMouth = new SimpleDateFormat(
            "yyyy-MM");
    
    private final static SimpleDateFormat sdfDays = new SimpleDateFormat(
    "yyyyMMdd");

    private final static SimpleDateFormat sdfTime = new SimpleDateFormat(
            "yyyy-MM-dd HH:mm:ss");
    
    public static final String DATE_FORMAT_FULL = "yyyy-MM-dd HH:mm:ss";
    
     public static final String DATE_FORMAT_FULL_MSEL = "yyyyMMddHHmmssSSSS";

    /**
     * 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());
    }

    /**
     * 传入一个时间字符串
     * 判断此时间在晚上23点到凌晨6点经过了多久分钟
     * YYYY-MM-DD HH:mm:ss
     */    
    public static int getNightSum( String s) {
        Date date = fomatDate(s);
        String str = sdfTime.format(date);
        String str2 = str.substring(11, 13);
        int i = Integer.parseInt(str2);
        if(i>=23){
         return Integer.parseInt(str.substring(14, 16));            
        }else if(i<6){
            i=6-i-1;
            int j=60-Integer.parseInt(str.substring(14, 16));
            return i*60+j;
        }else {
            return 0;
        }
    
    }
    
    
    
    
    /**
    * @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 luguosui
     */
    public static boolean compareDate(String s, String e) {
        if(fomatDate(s)==null||fomatDate(e)==null){
            return false;
        }
        return fomatDate(s).getTime() >=fomatDate(e).getTime();
    }

     /**
     * 得到时间戳
     * 
     * @param null
     * @return String 当前日期时间戳(yyyyMMddHHmmssSSSS)
     */
    public static String getTimeStamp() {
        try {
            Calendar now = Calendar.getInstance(TimeZone.getDefault());
            SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_FULL_MSEL);
            sdf.setTimeZone(TimeZone.getDefault());
            return (sdf.format(now.getTime()));
        } catch (Exception e) {
            return getCurDateTime(); // 如果无法转化，则返回默认格式的时间。
        }
    }
    
    /**
     * 得到当前日期
     * 
     * @return String 当前日期 yyyy-MM-dd HH:mm:ss格式
     */
    public static String getCurDateTime() {
        Calendar now = Calendar.getInstance(TimeZone.getDefault());
        // String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
        DateFormat sdf = new SimpleDateFormat(DATE_FORMAT_FULL);
        sdf.setTimeZone(TimeZone.getDefault());
        return (sdf.format(now.getTime()));
    }
    /**
     * 格式化日期
     * 
     * @return
     */
    public static Date fomatDate(String date) {
        DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        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;
        }
    }
    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;
    }
        
    /**
     * 将日期对象转为时间戳字符串
     * @param time
     * @return
     * @throws ParseException
     */
    public static String dateutil(String time) throws ParseException{
        SimpleDateFormat format = new  SimpleDateFormat("yyyy-MM-dd HH:mm");
        Date date = format.parse(time);
        time = ""+date.getTime();    
        return time;
    }
    
    
    /**
     * 将日期对象转为时间戳
     * @param time
     * @return
     * @throws ParseException
     */
    public static Long dateutilToLong(String time) throws ParseException{
        SimpleDateFormat format = new  SimpleDateFormat("yyyy-MM-dd HH:mm");
        Date date = format.parse(time);
        Long time2 = date.getTime();    
        return time2;
    }
    
    public static String parseDateToStr(Date thedate) {
        // String format = "yyyy-MM-dd";
        return parseDateToString(thedate, DATE_FORMAT_FULL);
    }
    
    public static String parseDateToString(Date thedate, String format) {
        DateFormat df = new SimpleDateFormat(format);
        if (thedate != null) {
            return df.format(thedate.getTime());
        }
        return "";
    }
    
    
    /**
     * 获取当前时间前一个月的时间
     * @param args
     */
    public static String getDateLastMouth(){
         Calendar c = Calendar.getInstance();
         c.setTime(new Date());
         c.add(Calendar.MONTH, -1);
         Date m = c.getTime();
        return sdfTime.format(m);
    }
    /**
     * 获取当月第一天的日期
     * @return
     */
    public static String getMouthNoOne(){       
       return sdfMouth.format(new Date())+"-01 00:00";
    }
    
    
    public static void main(String[] args) {
    
        boolean b = compareDate("2018-08-18 00:00", DateUtil.getTime());
        System.out.println(b);
    
    }
    
    
    
}