工具类--日期工具类

public class DateUtils {

    /**
     * 获取两个日期之间的所有日期
     */
    public static List<Date> getBetweenDates(Date begin, Date end) {
        List<Date> result = new ArrayList<Date>();
        Calendar tempStart = Calendar.getInstance();
        tempStart.setTime(begin);
        while(begin.getTime()<=end.getTime()){
            result.add(tempStart.getTime());
            tempStart.add(Calendar.DAY_OF_YEAR, 1);
            begin = tempStart.getTime();
        }
        return result;
    }

    /**
     * 获取当天 前几天的日期-1 2019-04-21 11:59:59
     * @return fewDays
     */
    public static String getBeforeDay(String fewDays){
        int days = Integer.valueOf(fewDays).intValue();
        days = days +1;
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd 00:00:00");
        //获取日历实例
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        //设置为前几天
        calendar.add(Calendar.DAY_OF_MONTH, -days);
        return sdf.format(calendar.getTime());
    }

    /**
     * 获取当天 前一天的日期 2019-04-21 11:59:59
     * @return fewDays
     */
    public static String getBeforeOneDay(){
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd 23:59:59");
        //获取日历实例
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        //设置为前几天
        calendar.add(Calendar.DAY_OF_MONTH, -1);
        return sdf.format(calendar.getTime());
    }

    /**
     * 获取当前年度
     * @author: donghaijian
     * @return
     */
    public static String getCurrentYear() {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy");
        Date date = new Date();
        return sdf.format(date);
    }

public static String parseDateToString(String pattern, Date date) {
   SimpleDateFormat sdf = new SimpleDateFormat(pattern);
   return sdf.format(date);
}

private static Date parseStringToDate(String pattern, String dateTime) {
   SimpleDateFormat sdf = new SimpleDateFormat(pattern);
   try {
      return sdf.parse(dateTime);
   } catch (ParseException e) {
      log.error(e.getMessage(), e);
      return null;
   }
}

public static boolean parseWeChatDate(String date) {
   if(date.length() != 8){
      return true;
   }
   try {
      Integer.parseInt(date);
   } catch (Exception e) {
      log.error(e.getMessage(), e);
      return true;
   }
   return false;
}

/**
 * 将一个字符串用给定的格式转换为日期类型。<br>
 * 注意：如果返回null，则表示解析失败
 *
 * @param datestr
 *            需要解析的日期字符串
 * @param pattern
 *            日期字符串的格式，默认为“yyyy-MM-dd”的形式
 * @return 解析后的日期
 */
public static Date parse(String datestr, String pattern) {
   Date date = null;
   if (null == pattern || "".equals(pattern)) {
      pattern = YYYY_MM_DD;
   }
   try {
      SimpleDateFormat dateFormat = new SimpleDateFormat(pattern);
      date = dateFormat.parse(datestr);
   } catch (ParseException e) {
   }
   return date;
}

/**
 * 获取指定时间N天前或者N天后的 日期
 * @param date 指定时间
 * @param n 正数后 负数前
 * @return date
 */
public static Date getNday(Date date, int n) {
   Calendar calendar = Calendar.getInstance();
   calendar.setTime(date);
   calendar.add(Calendar.DATE, n);
   return calendar.getTime();
}

}