Java工具类DateUtils实例详解

import java.text.parseexception;
import java.text.simpledateformat;
import java.util.calendar;
import java.util.date;
/**
 * 描述:公共日期工具类
 */
public class dateutils {

  public static string date_format = "yyyy-mm-dd";

  public static string date_time_format = "yyyy-mm-dd hh:mm:ss";

  public static string date_format_chinese = "yyyy年m月d日";

  /**
   * 获取当前日期
   * 
   * 
   * @return
   * 
   */
  public static string getcurrentdate() {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateutils.date_format);
    datestr = df.format(new date());
    return datestr;
  }

  /**
   * 获取当前日期时间
   * 
   * 
   * @return
   * 
   */
  public static string getcurrentdatetime() {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateutils.date_time_format);
    datestr = df.format(new date());
    return datestr;
  }

  /**
   * 获取当前日期时间
   * 
   * 
   * @return
   * 
   */
  public static string getcurrentdatetime(string dateformat) {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateformat);
    datestr = df.format(new date());
    return datestr;
  }

  public static string datetodatetime(date date) {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateutils.date_time_format);
    datestr = df.format(date);
    return datestr;
  }
  /**
   * 将字符串日期转换为日期格式
   * 
   * 
   * @param datestr
   * @return
   * 
   */
  public static date stringtodate(string datestr) {

      if(datestr ==null ||datestr.equals("")){
        return null;
      }
    date date = new date();
    simpledateformat df = new simpledateformat(dateutils.date_format);
    try {
      date = df.parse(datestr);
    } catch (parseexception e) {
      date=dateutils.stringtodate(datestr,"yyyymmdd");
    }
    return date;
  }

  /**
   * 将字符串日期转换为日期格式
   * 自定義格式
   * 
   * @param datestr
   * @return
   * 
   */
  public static date stringtodate(string datestr, string dateformat) {
    date date = new date();
    simpledateformat df = new simpledateformat(dateformat);
    try {
      date = df.parse(datestr);
    } catch (parseexception e) {
      e.printstacktrace();
    }
    return date;
  }




  /**
   * 将日期格式日期转换为字符串格式
   * 
   * 
   * @param date
   * @return
   * 
   */
  public static string datetostring(date date) {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateutils.date_format);
    datestr = df.format(date);
    return datestr;
  }

  /**
   * 将日期格式日期转换为字符串格式 自定義格式
   * 
   * @param date
   * @param dateformat
   * @return
   */
  public static string datetostring(date date, string dateformat) {
    string datestr = null;
    simpledateformat df = new simpledateformat(dateformat);
    datestr = df.format(date);
    return datestr;
  }

  /**
   * 获取日期的day值
   * 
   * 
   * @param date
   *      输入日期
   * @return
   * 
   */
  public static int getdayofdate(date date) {
    int d = 0;
    calendar cd = calendar.getinstance();
    cd.settime(date);
    d = cd.get(calendar.day_of_month);
    return d;
  }

  /**
   * 获取日期的month值
   * 
   * 
   * @param date
   *      输入日期
   * @return
   * 
   */
  public static int getmonthofdate(date date) {
    int m = 0;
    calendar cd = calendar.getinstance();
    cd.settime(date);
    m = cd.get(calendar.month) + 1;
    return m;
  }

  /**
   * 获取日期的year值
   * 
   * 
   * @param date
   *      输入日期
   * @return
   * 
   */
  public static int getyearofdate(date date) {
    int y = 0;
    calendar cd = calendar.getinstance();
    cd.settime(date);
    y = cd.get(calendar.year);
    return y;
  }

  /**
   * 获取星期几
   * 
   * 
   * @param date
   *      输入日期
   * @return
   * 
   */
  public static int getweekofdate(date date) {
    int wd = 0;
    calendar cd = calendar.getinstance();
    cd.settime(date);
    wd = cd.get(calendar.day_of_week) - 1;
    return wd;
  }

  /**
   * 获取输入日期的当月第一天
   * 
   * 
   * @param date
   *      输入日期
   * @return
   * 
   */
  public static date getfirstdayofmonth(date date) {
    calendar cd = calendar.getinstance();
    cd.settime(date);
    cd.set(calendar.day_of_month, 1);
    return cd.gettime();
  }

  /**
   * 获得输入日期的当月最后一天
   * 
   * @param date
   */
  public static date getlastdayofmonth(date date) {
    return dateutils.addday(dateutils.getfirstdayofmonth(dateutils.addmonth(date, 1)), -1);
  }

  /**
   * 判断是否是闰年
   * 
   * 
   * @param date
   *      输入日期
   * @return 是true 否false
   * 
   */
  public static boolean isleapyear(date date) {

    calendar cd = calendar.getinstance();
    cd.settime(date);
    int year = cd.get(calendar.year);

    if (year % 4 == 0 && year % 100 != 0 | year % 400 == 0) {
      return true;
    } else {
      return false;
    }
  }

  /**
   * 根据整型数表示的年月日，生成日期类型格式
   * 
   * @param year
   *      年
   * @param month
   *      月
   * @param day
   *      日
   * @return
   * 
   */
  public static date getdatebyymd(int year, int month, int day) {
    calendar cd = calendar.getinstance();
    cd.set(year, month-1, day);
    return cd.gettime();
  }

  /**
   * 获取年周期对应日
   * 
   * @param date
   *      输入日期
   * @param iyear
   *      年数  負數表示之前
   * @return
   * 
   */
  public static date getyearcycleofdate(date date, int iyear) {
    calendar cd = calendar.getinstance();
    cd.settime(date);

    cd.add(calendar.year, iyear);

    return cd.gettime();
  }

  /**
   * 获取月周期对应日
   * 
   * @param date
   *      输入日期
   * @param i
   * @return
   * 
   */
  public static date getmonthcycleofdate(date date, int i) {
    calendar cd = calendar.getinstance();
    cd.settime(date);

    cd.add(calendar.month, i);

    return cd.gettime();
  }

  /**
   * 计算 fromdate 到 todate 相差多少年
   * 
   * @param fromdate
   * @param todate
   * @return 年数
   * 
   */
  public static int getyearbyminusdate(date fromdate, date todate) {
    calendar df=calendar.getinstance();
    df.settime(fromdate);

    calendar dt=calendar.getinstance();
    dt.settime(todate);

    return dt.get(calendar.year)-df.get(calendar.year);
  }

  /**
   * 计算 fromdate 到 todate 相差多少个月
   * 
   * @param fromdate
   * @param todate
   * @return 月数
   * 
   */
  public static int getmonthbyminusdate(date fromdate, date todate) {
    calendar df=calendar.getinstance();
    df.settime(fromdate);

    calendar dt=calendar.getinstance();
    dt.settime(todate);

    return dt.get(calendar.year)*12+dt.get(calendar.month)-
        (df.get(calendar.year)*12+df.get(calendar.month));
  }

  /**
   * 计算 fromdate 到 todate 相差多少天
   * 
   * @param fromdate
   * @param todate
   * @return 天数
   * 
   */
  public static long getdaybyminusdate(object fromdate, object todate) {

    date f=dateutils.chgobject(fromdate);

    date t=dateutils.chgobject(todate);

    long fd=f.gettime();
    long td=t.gettime();

    return (td-fd)/(24l * 60l * 60l * 1000l);
  }

  /**
   * 计算年龄
   * 
   * @param birthday
   *      生日日期
   * @param calcdate
   *      要计算的日期点
   * @return
   * 
   */
  public static int calcage(date birthday, date calcdate) {

    int cyear=dateutils.getyearofdate(calcdate);
    int cmonth=dateutils.getmonthofdate(calcdate);
    int cday=dateutils.getdayofdate(calcdate);   
    int byear=dateutils.getyearofdate(birthday);
    int bmonth=dateutils.getmonthofdate(birthday);
    int bday=dateutils.getdayofdate(birthday);

    if(cmonth>bmonth||(cmonth==bmonth&&cday>bday)){
      return cyear-byear;
    }else{
      return cyear-1-byear;
    }
  }

  /**
   * 从身份证中获取出生日期
   * 
   * @param idno
   *      身份证号码
   * @return
   * 
   */
  public static string getbirthdayfromidcard(string idno) {
    calendar cd = calendar.getinstance();
    if (idno.length() == 15) {
      cd.set(calendar.year, integer.valueof("19" + idno.substring(6, 8))
          .intvalue());
      cd.set(calendar.month, integer.valueof(idno.substring(8, 10))
          .intvalue() - 1);
      cd.set(calendar.day_of_month,
          integer.valueof(idno.substring(10, 12)).intvalue());
    } else if (idno.length() == 18) {
      cd.set(calendar.year, integer.valueof(idno.substring(6, 10))
          .intvalue());
      cd.set(calendar.month, integer.valueof(idno.substring(10, 12))
          .intvalue() - 1);
      cd.set(calendar.day_of_month,
          integer.valueof(idno.substring(12, 14)).intvalue());
    }
    return dateutils.datetostring(cd.gettime());
  }

  /**
   * 在输入日期上增加（+）或减去（-）天数
   * 
   * @param date
   *      输入日期
   * @param imonth
   *      要增加或减少的天数
   */
  public static date addday(date date, int iday) {
    calendar cd = calendar.getinstance();

    cd.settime(date);

    cd.add(calendar.day_of_month, iday);

    return cd.gettime();
  }

  /**
   * 在输入日期上增加（+）或减去（-）月份
   * 
   * @param date
   *      输入日期
   * @param imonth
   *      要增加或减少的月分数
   */
  public static date addmonth(date date, int imonth) {
    calendar cd = calendar.getinstance();

    cd.settime(date);

    cd.add(calendar.month, imonth);

    return cd.gettime();
  }

  /**
   * 在输入日期上增加（+）或减去（-）年份
   * 
   * @param date
   *      输入日期
   * @param imonth
   *      要增加或减少的年数
   */
  public static date addyear(date date, int iyear) {
    calendar cd = calendar.getinstance();

    cd.settime(date);

    cd.add(calendar.year, iyear);

    return cd.gettime();
  }

  /**
   * 將object類型轉換為date
   * @param date
   * @return
   */
  public static date chgobject(object date){

    if(date!=null&&date instanceof date){
      return (date)date;
    }

    if(date!=null&&date instanceof string){
      return dateutils.stringtodate((string)date);
    }

    return null;

  }

  public static long getagebybirthday(string date){

    date birthday = stringtodate(date, "yyyy-mm-dd");
    long sec = new date().gettime() - birthday.gettime();

    long age = sec/(1000*60*60*24)/365;

    return age;
  }


  /**
   * @param args
   */
  public static void main(string[] args) {
    //string temp = dateutil.datetostring(getlastdayofmonth(new date()),
    ///   dateutil.date_format_chinese);
    //string s=dateutil.datetostring(dateutil.addday(dateutil.addyear(new date(),1),-1));


    long s=dateutils.getdaybyminusdate("2012-01-01", "2012-12-31");
    system.err.println(s);


  }

}