Java 时间工具类（计算距离现在多久、返回某个日期的前一天、 返回当月最后一天的日期、获取当前时间到凌晨还剩多少毫秒、获取当前时间前一个月第一天......）

package com.qycar.common.utils;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**

• 日期处理
  /
  public class DateUtils {
  /*

  • 时间格式(yyyy-MM-dd)
    /
    public static final String DATE_PATTERN = “yyyy-MM-dd”;
    public static final String MOTH_PATTERN = “yyyy-MM”;
    /*
  • 时间格式(yyyy-MM-dd HH:mm:ss)
    */
    public static final String DATE_TIME_PATTERN = “yyyy-MM-dd HH:mm:ss”;

  public static final String format(Date date) {
  return format(date, DATE_PATTERN);
  }

  public static String format(Date date, String pattern) {
  if (date != null) {
  SimpleDateFormat df = new SimpleDateFormat(pattern);
  return df.format(date);
  }
  return null;
  }

  /**

  • 计算距离现在多久，非精确
  • @param date
  • @return
    */
    public static String getTimeBefore(Date date) {
    Date now = new Date();
    long l = now.getTime() - date.getTime();
    long day = l / (24 * 60 * 60 * 1000);
    long hour = (l / (60 * 60 * 1000) - day * 24);
    long min = ((l / (60 * 1000)) - day * 24 * 60 - hour * 60);
    long s = (l / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60);
    String r = “”;
    if (day > 0) {
    r += day + “天”;
    } else if (hour > 0) {
    r += hour + “小时”;
    } else if (min > 0) {
    r += min + “分”;
    } else if (s > 0) {
    r += s + “秒”;
    }
    r += “前”;
    return r;
    }

  /**

  • 计算距离现在多久，精确
  • @param date
  • @return
    */
    public static String getTimeBeforeAccurate(Date date) {
    Date now = new Date();
    long l = now.getTime() - date.getTime();
    long day = l / (24 * 60 * 60 * 1000);
    long hour = (l / (60 * 60 * 1000) - day * 24);
    long min = ((l / (60 * 1000)) - day * 24 * 60 - hour * 60);
    long s = (l / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60);
    String r = “”;
    if (day > 0) {
    r += day + “天”;
    }
    if (hour > 0) {
    r += hour + “小时”;
    }
    if (min > 0) {
    r += min + “分”;
    }
    if (s > 0) {
    r += s + “秒”;
    }
    r += “前”;
    return r;
    }

  /**

  • 返回某个日期的前一天
    */
    public static Date getNextDay(Date date) {
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);
    calendar.add(Calendar.DAY_OF_MONTH, -1);
    date = calendar.getTime();
    return date;
    }

  /**

  • 返回当月最后一天的日期
    */
    public static Date getLastDayOfMonth(Date date) {
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);
    calendar.set(Calendar.DATE, calendar.getMaximum(Calendar.DATE));
    return calendar.getTime();
    }

  /**

  • 获取当前时间到凌晨还剩多少毫秒
    */
    public static long getMilliToDawn(){
    long milliSecondsLeftToday = 86400000 -
    org.apache.commons.lang3.time.DateUtils.getFragmentInMilliseconds(Calendar.getInstance(), Calendar.DATE);
    return milliSecondsLeftToday;
    }

  /**

  • 时间戳矫正（Java中标准的时间戳为13位）
    */
    public static long rectifyTimeStamp(long stateTime){
    //Java中标准的时间戳为13位
    String strTimeStamp = stateTime + “”;
    int len = strTimeStamp.length();
    for (int i = len; i < 13; i++) {
    strTimeStamp += “0”;
    }
    return Long.valueOf(strTimeStamp);
    }

  /**

  • 获取当前时间前一个月第一天
  • @return String
    */
    public static String getBeforeMonthFirstDay() {
    SimpleDateFormat sdf = new SimpleDateFormat(“yyyy-MM-dd”);
    Calendar calendar1 = Calendar.getInstance();
    calendar1.add(Calendar.MONTH, -1);
    calendar1.set(Calendar.DAY_OF_MONTH,1);
    String firstDay = sdf.format(calendar1.getTime());
    return firstDay;
    }

  /**

  • 获取前一个月最后一天
  • @return String
    */
    public static String getBeforeMonthLastDay() {
    //获取前一个月最后一天
    SimpleDateFormat sdf = new SimpleDateFormat(“yyyy-MM-dd”);
    Calendar calendar2 = Calendar.getInstance();
    calendar2.set(Calendar.DAY_OF_MONTH, 0);
    String lastDay = sdf.format(calendar2.getTime());
    return lastDay;
    }

}